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Compressing js file?

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  Compressing js file? emf <emfril@gmail.com> - 2013-12-23 14:31 -0500
    Re: Compressing js file? Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2013-12-23 22:08 -0200
    Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2013-12-23 16:40 -0800
      Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-24 13:23 -0500
      Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-26 21:56 -0500
        Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-27 09:52 +0100
          Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-27 08:18 -0500
            Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-27 16:59 +0100
              Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-27 15:32 -0500
                Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 15:12 -0500
                  Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 02:17 -0500
          Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-28 20:20 +0000
        XHR with timing issues (was: Compressing js file?) Christoph Michael Becker <cmbecker69@arcor.de> - 2013-12-27 22:33 +0100
          Re: XHR with timing issues (was: Compressing js file?) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-12-27 23:26 +0100
            Re: XHR with timing issues Christoph Michael Becker <cmbecker69@arcor.de> - 2013-12-28 12:08 +0100
              Re: XHR with timing issues emf <emfril@gmail.com> - 2013-12-28 09:04 -0500
    Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-27 22:33 +0100
      Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 00:16 -0500
        Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-28 11:13 +0100
          Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 11:26 -0500
            Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-28 13:53 -0500
              Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-28 21:00 +0100
                Re: Compressing js file? emf <emfril@gmail.com> - 2013-12-29 21:47 -0500
                  Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2013-12-31 14:05 -0800
                    Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 02:50 -0500
                      Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 01:16 -0800
                        Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 08:13 -0500
                          Re: Compressing js file? Tim Streater <timstreater@greenbee.net> - 2014-01-01 14:17 +0000
                          Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 15:31 -0800
                          Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-01 18:38 -0500
                            Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-01 15:45 -0800
                              Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-02 11:43 -0500
                                Re: Compressing js file? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-01-02 09:34 -0800
                                  OT: Compressing js file? Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-02 19:52 +0100
                                  Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-03 07:19 -0500
                                  Re: Compressing js file? emf <emfril@gmail.com> - 2014-01-03 07:31 -0500
                            Re: Compressing js file? Tim Streater <timstreater@greenbee.net> - 2014-01-02 09:14 +0000
                      Re: Compressing js file? Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-01 16:25 +0000
                        Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-01 21:36 +0100
            Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-29 20:06 +0100
              Re: Compressing js file? wolfgang zeidler <invalid@invalid.invalid> - 2013-12-29 20:27 +0100
          Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-29 18:02 +0000
            Re: Compressing js file? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2013-12-30 18:17 +0100
              Re: Compressing js file? John Harris <niam@jghnorth.org.uk.invalid> - 2013-12-31 10:52 +0000
              Re: Compressing js file? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-12-31 13:38 +0000
                Re: Compressing js file? John Harris <niam@jghnorth.org.uk.invalid> - 2013-12-31 15:02 +0000
                  Re: Compressing js file? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-01-01 16:42 +0000
                  Re: Compressing js file? Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-01-01 21:32 +0000
              Re: Compressing js file? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-31 21:44 +0000

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#22375 — Compressing js file?

Since Java has security problems and soon I might have to buy a 
certificate, I decided to convert my Natal Transits Calculator Java 
program to JavaScript:

Java program, calculating 5 planets:

https://files.nyu.edu/emf202/public/jv/nataltransits.html

JavaScript program, calculating 2 planets (page still under construction):

https://files.nyu.edu/emf202/public/nt/natalTransits.html

The issue is this:

The programs use a large ephemeris file. The size of the original 
ephemeris.csv with 5 planets is 2.141 KB. It's in the form of

19000101,01i08,27i43,10i08,25c13,15c15
19000102,01i20,27i50,10i12,25c12,15c14
...

The size of the jar file that includes the compressed ephemeris.csv, the 
program files, and the code files is only 735 KB!

The size of the ephemeris.js with only 2 planets is 1,606 KB. It 
includes the ephem array that is in the form:

var ephem = [["19000101","27i43","10i08"], ["19000102","27i50","10i12"], 
... ];

The choice of including only 2 planets was *not* made mainly on file 
size considerations. And BTW, with the JavaScript program I was able to 
use the Unicode sign symbols, something problematic with the Java 
program. (I hope everybody out there can see them.)

My question is: Is there a way to make the data file smaller and still 
be able to read it with the JavaScript program?

And by smaller, of course, I do not mean eliminating the spaces between 
the elements of the array that would save only 3%.

Thanks,

Eustace

PS. I remember that last time I visited the newsgroup, more than 1 year 
ago, it was more active. Where have all the other programmers gone?

-- 
Google's *top* Spherical Triangle Calculator search result!
https://files.nyu.edu/emf202/public/js/spherical.html

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#22376

On 23-12-2013 17:31, emf wrote:
> Since Java has security problems and soon I might have to buy a
> certificate, I decided to convert my Natal Transits Calculator Java
> program to JavaScript:

Then you might be using Scala instead, because JavaScript is not a 
better option in terms of security.

<snip>

> My question is: Is there a way to make the data file smaller and still
> be able to read it with the JavaScript program?

Maybe gzip or minification? I know there are some JavaScript libraries 
that work with zipped files too, but I'll pass on this one.

> PS. I remember that last time I visited the newsgroup, more than 1 year
> ago, it was more active. Where have all the other programmers gone?
>

There have been some important casualties in c.l.js: Kangax, David Mark, 
Richard Cornford, Asen Bozhilov, Dmitry Soshnikov. The long-term 
survivors seem to be Thomas Lahn, Dr John Stockton, Evertjian.

--
Joao Rodrigues (J.R)

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#22379

On Monday, December 23, 2013 1:31:41 PM UTC-6, emf wrote:
> Since Java has security problems and soon I might have to buy a 
> certificate, I decided to convert my Natal Transits Calculator Java 
> program to JavaScript:
> 
> Java program, calculating 5 planets:
> 
> https://files.nyu.edu/emf202/public/jv/nataltransits.html
> 
> JavaScript program, calculating 2 planets (page still under construction):
> 
> https://files.nyu.edu/emf202/public/nt/natalTransits.html
> 
> The issue is this:
> 
> The programs use a large ephemeris file. The size of the original 
> ephemeris.csv with 5 planets is 2.141 KB. It's in the form of
> 
> 19000101,01i08,27i43,10i08,25c13,15c15
> 19000102,01i20,27i50,10i12,25c12,15c14
> ...
> 
> The size of the jar file that includes the compressed ephemeris.csv, the 
> program files, and the code files is only 735 KB!
> 
> The size of the ephemeris.js with only 2 planets is 1,606 KB. It 
> includes the ephem array that is in the form:
> 
> var ephem = [["19000101","27i43","10i08"], ["19000102","27i50","10i12"], 
> ... ];
> 
> The choice of including only 2 planets was *not* made mainly on file 
> size considerations. And BTW, with the JavaScript program I was able to 
> use the Unicode sign symbols, something problematic with the Java 
> program. (I hope everybody out there can see them.)
> 
> My question is: Is there a way to make the data file smaller and still 
> be able to read it with the JavaScript program?
> 
> And by smaller, of course, I do not mean eliminating the spaces between 
> the elements of the array that would save only 3%.

I'd suggest leaving the data in csv form. On the fly, parse the desired elements using a regular expression to get its components. Alternatively|additionally, use gzip.

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#22385

On 2013-12-23 19:40 Michael Haufe (TNO) wrote:
> On Monday, December 23, 2013 1:31:41 PM UTC-6, emf wrote:
>> Since Java has security problems and soon I might have to buy a
>> certificate, I decided to convert my Natal Transits Calculator Java
>> program to JavaScript:
>>
>> Java program, calculating 5 planets:
>>
>> https://files.nyu.edu/emf202/public/jv/nataltransits.html
>>
>> JavaScript program, calculating 2 planets (page still under construction):
>>
>> https://files.nyu.edu/emf202/public/nt/natalTransits.html
>>
>> The issue is this:
>>
>> The programs use a large ephemeris file. The size of the original
>> ephemeris.csv with 5 planets is 2.141 KB. It's in the form of
>>
>> 19000101,01i08,27i43,10i08,25c13,15c15
>> 19000102,01i20,27i50,10i12,25c12,15c14
>> ...
>>
>> The size of the jar file that includes the compressed ephemeris.csv, the
>> program files, and the code files is only 735 KB!
>>
>> The size of the ephemeris.js with only 2 planets is 1,606 KB. It
>> includes the ephem array that is in the form:
>>
>> var ephem = [["19000101","27i43","10i08"], ["19000102","27i50","10i12"],
>> ... ];
>>
>> The choice of including only 2 planets was *not* made mainly on file
>> size considerations. And BTW, with the JavaScript program I was able to
>> use the Unicode sign symbols, something problematic with the Java
>> program. (I hope everybody out there can see them.)
>>
>> My question is: Is there a way to make the data file smaller and still
>> be able to read it with the JavaScript program?
>>
>> And by smaller, of course, I do not mean eliminating the spaces between
>> the elements of the array that would save only 3%.
>
> I'd suggest leaving the data in csv form. On the fly, parse the
> desired elements using a regular expression to get its components.
> Alternatively|additionally, use gzip.

I was not aware that I could read a file with JavaScript. I googled it 
and I started looking on this. I'll follow up here if I encounter 
insurmountable obstacles and need further expert advice. BTW, I 
corrected the code so that the program runs in IE too.

Thanks,

Eustace

-- 
Google's top Spherical Triangle Calculator search result!
https://files.nyu.edu/emf202/public/js/spherical.html

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#22419

On 2013-12-23 19:40 Michael Haufe (TNO) wrote:
> On Monday, December 23, 2013 1:31:41 PM UTC-6, emf wrote:
>> Since Java has security problems and soon I might have to buy a
>> certificate, I decided to convert my Natal Transits Calculator Java
>> program to JavaScript:
>>
>> Java program, calculating 5 planets:
>>
>> https://files.nyu.edu/emf202/public/jv/nataltransits.html
>>
>> JavaScript program, calculating 2 planets (page still under construction):
>>
>> https://files.nyu.edu/emf202/public/nt/natalTransits.html
>>
>> The issue is this:
>>
>> The programs use a large ephemeris file. The size of the original
>> ephemeris.csv with 5 planets is 2.141 KB. It's in the form of
>>
>> 19000101,01i08,27i43,10i08,25c13,15c15
>> 19000102,01i20,27i50,10i12,25c12,15c14
>> ...
>>
>> The size of the jar file that includes the compressed ephemeris.csv, the
>> program files, and the code files is only 735 KB!
>>
>> The size of the ephemeris.js with only 2 planets is 1,606 KB. It
>> includes the ephem array that is in the form:
>>
>> var ephem = [["19000101","27i43","10i08"], ["19000102","27i50","10i12"],
>> ... ];
>>
>> The choice of including only 2 planets was *not* made mainly on file
>> size considerations. And BTW, with the JavaScript program I was able to
>> use the Unicode sign symbols, something problematic with the Java
>> program. (I hope everybody out there can see them.)
>>
>> My question is: Is there a way to make the data file smaller and still
>> be able to read it with the JavaScript program?
>>
>> And by smaller, of course, I do not mean eliminating the spaces between
>> the elements of the array that would save only 3%.
>
> I'd suggest leaving the data in csv form. On the fly, parse the
> desired elements using a regular expression to get its components.
> Alternatively|additionally, use gzip.

I had read about AJAX and reading files, but had not payed attention to 
its possibilities and had managed to forget about it. Using a csv file 
is of course better since it's 1178 KB while the js was 1606 KB. (I have 
uploaded it at https://files.nyu.edu/emf202/public/nt/ephemeris.csv). 
I'll come to the gzip and other issues at a later point.

For now I've written a test webpage to access a local csv file. The code is:

<!DOCTYPE html>
<html>
   <head><meta charset="utf-8" />
     <title>Read File</title>
     <script type="text/javascript">

       var reader, ephem = [];
       reader = new XMLHttpRequest();

       function loadFile() {
         reader.open('get', 'ephemeris.csv', true);
         reader.send(null);
       }

       function leapDay(yyyy) {
         var lDay;
         lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy % 400 ===
           0) ? 1 : 0;
         return lDay;
       }
       function isValid(yyyy, mm, dd) {
         var valid;
         if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
           && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
           mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
           valid = true;
         } else {
           valid = false;
         }
         return valid;
       }

       function findBDay() {
         var yyyy, mm, dd, yyyyS, mmS, ddS, birthday, i;
         yyyy = +document.dataForm.yField.value;
         mm = +document.dataForm.mField.value;
         dd = +document.dataForm.dField.value;
         if ( ((yyyy < 1900) || (yyyy > 2049)) || (!isValid(yyyy, mm,
           dd)) ) {
           i = -1;
         } else {
           yyyyS = yyyy.toString();
           mmS = (mm < 10) ? "0" + mm : mm;
           ddS = (dd < 10) ? "0" + dd : dd;
           document.dataForm.mField.value = mmS;
           document.dataForm.dField.value = ddS;
           birthday = yyyyS + mmS + ddS;
           //alert("Press OK to continue.");
           for (i = 0; i < ephem.length; i += 1) {
             if (birthday === ephem[i][0]) {
               break;
             }
           }
         }
         return i;
       }

       function ephemArray(data) {
         var i, j, birthday, saturn, uranus;
         for (i = 0; i < data.length / 22; i += 1) {
           ephem[i] = [];
         }
         for (i = 0; i < data.length / 22; i += 1) {
           j = i * 22;
           birthday = data.substr(j, 8);
           saturn = data.substr(j + 9, 5);
           uranus = data.substr(j + 15, 5);
           ephem[i][0] = birthday;
           ephem[i][1] = saturn;
           ephem[i][2] = uranus;
         }
       }

       function loadData() {
         var data;
         if(reader.readyState === 4) {
           data = reader.responseText;
           ephemArray(data);
         }
       }

       function findBirthData() {
         var bDay;
         loadFile();
         reader.onreadystatechange = loadData;
         bDay = findBDay();
         if (bDay >= 0) {
           document.dataForm.outputArea.value +=
             "\n" + ephem[bDay][0] + " " + ephem[bDay][1] + " " +
             ephem[bDay][2];
         } else {
           document.dataForm.outputArea.value +=
             "\n" + "Invalid entry";
         }
       }
     </script>
     </head>
     <body onLoad="document.dataForm.outputArea.value='';">
       <form name="dataForm" action="">
         Enter birthday (yyyy-m-d):
         <input type="text" name="yField" value="" size=4> -
         <input type="text" name="mField" value="" size=2> -
         <input type="text" name="dField" value="" size=2>
         <input type="button" value="  Find  "
           onclick="findBirthData()">
         <textarea name="outputArea" rows="16" cols="43"></textarea></td>
       </form>
     </body>
</html>

The problem is that unless I un-comment the alert in the findBDay 
function, the first time I click on the button nothing happens because 
ephem hasn't yet be loaded. When I click the button a second time it 
works OK.

I tried to start the loadFile() with <body onload="...> but it doesn't 
work. I've also tried to delay the execution of the for loop in the 
findBDay function while ephem.length is 0, but haven't managed to find a 
working solution. Only the alert works, but of course this is not a 
satisfactory solution.

Suggestions?

emf

-- 
It ain't THAT, babe! - A radical reinterpretation
https://files.nyu.edu/emf202/public/bd/itaintmebabe.html

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#22420

emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:

>      function leapDay(yyyy) {
>          var lDay;
>          lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy % 400 ===
>            0) ? 1 : 0;
>          return lDay;
>        }

Better call this isLeapYear(y), 
[I presume that is what you ment]
use the Javascript Date object,
and have it return true/false:
[warning: Javascript Januari = month 0]

function isLeapYear(y) {
   return !(new Date(y, 1, 29).getMonth()-1);
};


>        function isValid(yyyy, mm, dd) {
>          var valid;
>          if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
>            && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
>            mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
>            valid = true;
>          } else {
>            valid = false;
>          }
>          return valid;
>        }

same objection to dubious function naming 
and lack of possible compactness here:

function isValidDate(y, m, d) {
   var t = new Date(y, m-1, d);
   return t.getMonth()+1 == m  &&  t.getDate() == d;
};

if you prefer, 
[and if you still need the isLeapDayYear at all?]
you could now also do:

function isLeapYear(y) {
   return isValidDate(y, 2, 29);
};



-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#22424

On 2013-12-27 03:52 Evertjan. wrote:
> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>
>>       function leapDay(yyyy) {
>>           var lDay;
>>           lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy % 400 ===
>>             0) ? 1 : 0;
>>           return lDay;
>>         }
>
> Better call this isLeapYear(y),
> [I presume that is what you ment]
> use the Javascript Date object,
> and have it return true/false:
> [warning: Javascript Januari = month 0]
>
> function isLeapYear(y) {
>     return !(new Date(y, 1, 29).getMonth()-1);
> };
>
>
>>         function isValid(yyyy, mm, dd) {
>>           var valid;
>>           if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
>>             && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
>>             mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
>>             valid = true;
>>           } else {
>>             valid = false;
>>           }
>>           return valid;
>>         }
>
> same objection to dubious function naming
> and lack of possible compactness here:
>
> function isValidDate(y, m, d) {
>     var t = new Date(y, m-1, d);
>     return t.getMonth()+1 == m  &&  t.getDate() == d;
> };
>
> if you prefer,
> [and if you still need the isLeapDayYear at all?]
> you could now also do:
>
> function isLeapYear(y) {
>     return isValidDate(y, 2, 29);
> };

I first wrote my date subroutines in QBasic in the early '90s soon after 
taking a 1 credit course at a Community College. I've kept updating them 
as my understanding of programming changed over the years, as I do with 
the code of my webpages. Their latest reincarnation is in the JavaScript 
program:

https://files.nyu.edu/emf202/public/js/dateCalculator.html

which still works perfectly well and it has historical importance for 
me, besides presenting a historian's view on the issue. I haven't, 
however, updated the page for some time, and I am well aware I need to 
do it, because since I wrote it I've learned Java, which modified my 
views for variable names etc. a lot.

Every time I visit this newsgroup and the issue comes up, Dr. John 
Stockton always finds some (valid) reason to express his dissatisfaction 
with my program, and I've come to accept it as an inevitable fact of life.

I wish I would delve now on your suggestions, but it will have to wait 
until I decide to sit down and revise the whole date program.

Cheers,

Eustace

-- 
It ain't THAT, babe! - A radical reinterpretation
https://files.nyu.edu/emf202/public/bd/itaintmebabe.html

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#22428

emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:

> On 2013-12-27 03:52 Evertjan. wrote:
>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>>
>>>       function leapDay(yyyy) {
>>>           var lDay;
>>>           lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy % 400 ===
>>>             0) ? 1 : 0;
>>>           return lDay;
>>>         }
>>
>> Better call this isLeapYear(y),
>> [I presume that is what you ment]
>> use the Javascript Date object,
>> and have it return true/false:
>> [warning: Javascript Januari = month 0]
>>
>> function isLeapYear(y) {
>>     return !(new Date(y, 1, 29).getMonth()-1);
>> };
>>
>>
>>>         function isValid(yyyy, mm, dd) {
>>>           var valid;
>>>           if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
>>>             && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
>>>             mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
>>>             valid = true;
>>>           } else {
>>>             valid = false;
>>>           }
>>>           return valid;
>>>         }
>>
>> same objection to dubious function naming
>> and lack of possible compactness here:
>>
>> function isValidDate(y, m, d) {
>>     var t = new Date(y, m-1, d);
>>     return t.getMonth()+1 == m  &&  t.getDate() == d;
>> };
>>
>> if you prefer,
>> [and if you still need the isLeapDayYear at all?]
>> you could now also do:
>>
>> function isLeapYear(y) {
>>     return isValidDate(y, 2, 29);
>> };
> 
> I first wrote my date subroutines in QBasic in the early '90s soon after 
> taking a 1 credit course at a Community College. I've kept updating them 
> as my understanding of programming changed over the years, as I do with 
> the code of my webpages. Their latest reincarnation is in the JavaScript 
> program:
> 
> https://files.nyu.edu/emf202/public/js/dateCalculator.html
> 
> which still works perfectly well and it has historical importance for 
> me, besides presenting a historian's view on the issue. I haven't, 
> however, updated the page for some time, and I am well aware I need to 
> do it, because since I wrote it I've learned Java, which modified my 
> views for variable names etc. a lot.
> 
> Every time I visit this newsgroup and the issue comes up, Dr. John 
> Stockton always finds some (valid) reason to express his dissatisfaction 
> with my program, and I've come to accept it as an inevitable fact of life.
> 
> I wish I would delve now on your suggestions, but it will have to wait 
> until I decide to sit down and revise the whole date program.

Dear Eustace,

Then why do you post those functions, if not to discuss them in this 
discussion group? 

Methinks such optimalisation mind games cannot wait till you do a complete 
revision, as then you would not have the time nor the inclination to play 
with these concepts and improve on detailed knowledge of the possibilities 
of this modern computer language. [Yes, I project my way of thinking and 
learning on you, sorry if you don't like that].

That does not mean you should implement it now in your code, but why not 
play with it, like I just did, so that it comes naturally when you enter the 
revision state? 

Giving comrehensice and sensible names to functions, subroutines if you 
like, has come a long way and makes remarks remarkably less obligatory as 
compared to the days of assembler programming.

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#22438

On 2013-12-27 10:59 Evertjan. wrote:
> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>
>> On 2013-12-27 03:52 Evertjan. wrote:
>>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>>>
>>>>        function leapDay(yyyy) {
>>>>            var lDay;
>>>>            lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy % 400 ===
>>>>              0) ? 1 : 0;
>>>>            return lDay;
>>>>          }
>>>
>>> Better call this isLeapYear(y),
>>> [I presume that is what you ment]
>>> use the Javascript Date object,
>>> and have it return true/false:
>>> [warning: Javascript Januari = month 0]
>>>
>>> function isLeapYear(y) {
>>>      return !(new Date(y, 1, 29).getMonth()-1);
>>> };
>>>
>>>
>>>>          function isValid(yyyy, mm, dd) {
>>>>            var valid;
>>>>            if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
>>>>              && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
>>>>              mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
>>>>              valid = true;
>>>>            } else {
>>>>              valid = false;
>>>>            }
>>>>            return valid;
>>>>          }
>>>
>>> same objection to dubious function naming
>>> and lack of possible compactness here:
>>>
>>> function isValidDate(y, m, d) {
>>>      var t = new Date(y, m-1, d);
>>>      return t.getMonth()+1 == m  &&  t.getDate() == d;
>>> };
>>>
>>> if you prefer,
>>> [and if you still need the isLeapDayYear at all?]
>>> you could now also do:
>>>
>>> function isLeapYear(y) {
>>>      return isValidDate(y, 2, 29);
>>> };
>>
>> I first wrote my date subroutines in QBasic in the early '90s soon after
>> taking a 1 credit course at a Community College. I've kept updating them
>> as my understanding of programming changed over the years, as I do with
>> the code of my webpages. Their latest reincarnation is in the JavaScript
>> program:
>>
>> https://files.nyu.edu/emf202/public/js/dateCalculator.html
>>
>> which still works perfectly well and it has historical importance for
>> me, besides presenting a historian's view on the issue. I haven't,
>> however, updated the page for some time, and I am well aware I need to
>> do it, because since I wrote it I've learned Java, which modified my
>> views for variable names etc. a lot.
>>
>> Every time I visit this newsgroup and the issue comes up, Dr. John
>> Stockton always finds some (valid) reason to express his dissatisfaction
>> with my program, and I've come to accept it as an inevitable fact of life.
>>
>> I wish I would delve now on your suggestions, but it will have to wait
>> until I decide to sit down and revise the whole date program.
>
> Dear Eustace,
>
> Then why do you post those functions, if not to discuss them in this
> discussion group?

You are right. I made a mistake. I should have included just 1 line in 
the code:

<script type="text/javascript" src="dateCalculations.js"></script>

so that I wouldn't inadvertently have shifted the focus away from the 
immediate problem. Here is the revised code with 3 new alerts:

<!DOCTYPE html>
<html>
   <head><meta charset="utf-8" />
     <title>Read File</title>
     <script type="text/javascript" src="dateCalculations.js"></script>
     <script type="text/javascript">

       var reader, ephem = [];
       reader = new XMLHttpRequest();

       function ephemArray(data) {
         var i, j, birthday, saturn, uranus;
         for (i = 0; i < data.length / 22; i += 1) {
           ephem[i] = [];
         }
         for (i = 0; i < data.length / 22; i += 1) {
           j = i * 22;
           birthday = data.substr(j, 8);
           saturn = data.substr(j + 9, 5);
           uranus = data.substr(j + 15, 5);
           ephem[i][0] = birthday;
           ephem[i][1] = saturn;
           ephem[i][2] = uranus;
         }
         alert("1 " + ephem.length);
       }

       function loadData() {
         var data;
         if(reader.readyState === 4) {
           data = reader.responseText;
           ephemArray(data);
         }
       }

       function loadFile() {
         reader.open('get', 'ephemeris.csv', true);
         reader.send(null);
       }

       function findBDay() {
         var yyyy, mm, dd, yyyyS, mmS, ddS, birthday, i;
         yyyy = +document.dataForm.yField.value;
         mm = +document.dataForm.mField.value;
         dd = +document.dataForm.dField.value;
         if ( ((yyyy < 1900) || (yyyy > 2049)) || (!isValid(yyyy, mm,
           dd)) ) {
           i = -1;
         } else {
           yyyyS = yyyy.toString();
           mmS = (mm < 10) ? "0" + mm : mm;
           ddS = (dd < 10) ? "0" + dd : dd;
           document.dataForm.mField.value = mmS;
           document.dataForm.dField.value = ddS;
           birthday = yyyyS + mmS + ddS;
alert("3 " + ephem.length);
           for (i = 0; i < ephem.length; i += 1) {
             if (birthday === ephem[i][0]) {
               break;
             }
           }
         }
         return i;
       }

       function findBirthData() {
         var bDay;
         loadFile();
         reader.onreadystatechange = loadData;
alert("2 " + ephem.length);
         bDay = findBDay();
         if (bDay >= 0) {
           document.dataForm.outputArea.value +=
             "\n" + ephem[bDay][0] + " " + ephem[bDay][1] + " " +
             ephem[bDay][2];
         } else {
           document.dataForm.outputArea.value +=
             "\n" + "Invalid entry";
         }
       }
     </script>
     </head>
     <body onLoad="document.dataForm.outputArea.value='';">
       <form name="dataForm" action="">
         Enter birthday (yyyy-m-d):
         <input type="text" name="yField" value="" size=4> -
         <input type="text" name="mField" value="" size=2> -
         <input type="text" name="dField" value="" size=2>
         <input type="button" value="  Find  "
           onclick="findBirthData()">
         <textarea name="outputArea" rows="16" cols="43"></textarea></td>
       </form>
     </body>
</html>

I have included 3 alerts to get the ephem.length. In alert 1 the length 
is given correctly as 54787. In alert 2, before calling the findBDay 
functions it has become 0! In alert 3, inside the bDay function, it has 
reverted to 54787.

In the chart below - means that the alert has been commented out. OK 
means that I get results without having to click again on the button.

alert 1    alert 2    alert 3    results
54787      0          54787      OK
-          0          54787      OK
54787      -          0          OK
54787      0          -          OK
-          -          0          OK
-          0          -          OK
-          -          0          OK
-          -          -          !OK

So if any one alert is executed, we get results with the first click.

Alert 1 always gives 54787.

Alert 2 always gives 0.

Alert 3 gives 54787 if alert 2 has execute before, otherwise it gives 0.

We get results on the first click if any of the 3 alerts has been executed.

Can anybody make sense out of this? I cannot.

Eustace

-- 
Google's top Spherical Triangle Calculator search result!
https://files.nyu.edu/emf202/public/js/spherical.html

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#22456

On 2013-12-27 15:32 emf wrote:
> On 2013-12-27 10:59 Evertjan. wrote:
>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>>
>>> On 2013-12-27 03:52 Evertjan. wrote:
>>>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>>>>
>>>>>        function leapDay(yyyy) {
>>>>>            var lDay;
>>>>>            lDay = ((yyyy % 4 === 0 && yyyy % 100 !== 0) || yyyy %
>>>>> 400 ===
>>>>>              0) ? 1 : 0;
>>>>>            return lDay;
>>>>>          }
>>>>
>>>> Better call this isLeapYear(y),
>>>> [I presume that is what you ment]
>>>> use the Javascript Date object,
>>>> and have it return true/false:
>>>> [warning: Javascript Januari = month 0]
>>>>
>>>> function isLeapYear(y) {
>>>>      return !(new Date(y, 1, 29).getMonth()-1);
>>>> };
>>>>
>>>>
>>>>>          function isValid(yyyy, mm, dd) {
>>>>>            var valid;
>>>>>            if (yyyy > 0 && mm > 0 && mm <= 12 && dd > 0 && dd <= 31
>>>>>              && !(dd === 31 && (mm === 4 || mm === 6 || mm === 9 ||
>>>>>              mm === 11)) && !(mm === 2 && dd > 28 + leapDay(yyyy))) {
>>>>>              valid = true;
>>>>>            } else {
>>>>>              valid = false;
>>>>>            }
>>>>>            return valid;
>>>>>          }
>>>>
>>>> same objection to dubious function naming
>>>> and lack of possible compactness here:
>>>>
>>>> function isValidDate(y, m, d) {
>>>>      var t = new Date(y, m-1, d);
>>>>      return t.getMonth()+1 == m  &&  t.getDate() == d;
>>>> };
>>>>
>>>> if you prefer,
>>>> [and if you still need the isLeapDayYear at all?]
>>>> you could now also do:
>>>>
>>>> function isLeapYear(y) {
>>>>      return isValidDate(y, 2, 29);
>>>> };
>>>
>>> I first wrote my date subroutines in QBasic in the early '90s soon after
>>> taking a 1 credit course at a Community College. I've kept updating them
>>> as my understanding of programming changed over the years, as I do with
>>> the code of my webpages. Their latest reincarnation is in the JavaScript
>>> program:
>>>
>>> https://files.nyu.edu/emf202/public/js/dateCalculator.html
>>>
>>> which still works perfectly well and it has historical importance for
>>> me, besides presenting a historian's view on the issue. I haven't,
>>> however, updated the page for some time, and I am well aware I need to
>>> do it, because since I wrote it I've learned Java, which modified my
>>> views for variable names etc. a lot.
>>>
>>> Every time I visit this newsgroup and the issue comes up, Dr. John
>>> Stockton always finds some (valid) reason to express his dissatisfaction
>>> with my program, and I've come to accept it as an inevitable fact of
>>> life.
>>>
>>> I wish I would delve now on your suggestions, but it will have to wait
>>> until I decide to sit down and revise the whole date program.
>>
>> Dear Eustace,
>>
>> Then why do you post those functions, if not to discuss them in this
>> discussion group?
>
> You are right. I made a mistake. I should have included just 1 line in
> the code:
>
> <script type="text/javascript" src="dateCalculations.js"></script>
>
> so that I wouldn't inadvertently have shifted the focus away from the
> immediate problem. Here is the revised code with 3 new alerts:
>
> <!DOCTYPE html>
> <html>
>    <head><meta charset="utf-8" />
>      <title>Read File</title>
>      <script type="text/javascript" src="dateCalculations.js"></script>
>      <script type="text/javascript">
>
>        var reader, ephem = [];
>        reader = new XMLHttpRequest();
>
>        function ephemArray(data) {
>          var i, j, birthday, saturn, uranus;
>          for (i = 0; i < data.length / 22; i += 1) {
>            ephem[i] = [];
>          }
>          for (i = 0; i < data.length / 22; i += 1) {
>            j = i * 22;
>            birthday = data.substr(j, 8);
>            saturn = data.substr(j + 9, 5);
>            uranus = data.substr(j + 15, 5);
>            ephem[i][0] = birthday;
>            ephem[i][1] = saturn;
>            ephem[i][2] = uranus;
>          }
>          alert("1 " + ephem.length);
>        }
>
>        function loadData() {
>          var data;
>          if(reader.readyState === 4) {
>            data = reader.responseText;
>            ephemArray(data);
>          }
>        }
>
>        function loadFile() {
>          reader.open('get', 'ephemeris.csv', true);
>          reader.send(null);
>        }
>
>        function findBDay() {
>          var yyyy, mm, dd, yyyyS, mmS, ddS, birthday, i;
>          yyyy = +document.dataForm.yField.value;
>          mm = +document.dataForm.mField.value;
>          dd = +document.dataForm.dField.value;
>          if ( ((yyyy < 1900) || (yyyy > 2049)) || (!isValid(yyyy, mm,
>            dd)) ) {
>            i = -1;
>          } else {
>            yyyyS = yyyy.toString();
>            mmS = (mm < 10) ? "0" + mm : mm;
>            ddS = (dd < 10) ? "0" + dd : dd;
>            document.dataForm.mField.value = mmS;
>            document.dataForm.dField.value = ddS;
>            birthday = yyyyS + mmS + ddS;
> alert("3 " + ephem.length);
>            for (i = 0; i < ephem.length; i += 1) {
>              if (birthday === ephem[i][0]) {
>                break;
>              }
>            }
>          }
>          return i;
>        }
>
>        function findBirthData() {
>          var bDay;
>          loadFile();
>          reader.onreadystatechange = loadData;
> alert("2 " + ephem.length);
>          bDay = findBDay();
>          if (bDay >= 0) {
>            document.dataForm.outputArea.value +=
>              "\n" + ephem[bDay][0] + " " + ephem[bDay][1] + " " +
>              ephem[bDay][2];
>          } else {
>            document.dataForm.outputArea.value +=
>              "\n" + "Invalid entry";
>          }
>        }
>      </script>
>      </head>
>      <body onLoad="document.dataForm.outputArea.value='';">
>        <form name="dataForm" action="">
>          Enter birthday (yyyy-m-d):
>          <input type="text" name="yField" value="" size=4> -
>          <input type="text" name="mField" value="" size=2> -
>          <input type="text" name="dField" value="" size=2>
>          <input type="button" value="  Find  "
>            onclick="findBirthData()">
>          <textarea name="outputArea" rows="16" cols="43"></textarea></td>
>        </form>
>      </body>
> </html>
>
> I have included 3 alerts to get the ephem.length. In alert 1 the length
> is given correctly as 54787. In alert 2, before calling the findBDay
> functions it has become 0! In alert 3, inside the bDay function, it has
> reverted to 54787.
>
> In the chart below - means that the alert has been commented out. OK
> means that I get results without having to click again on the button.
>
> alert 1    alert 2    alert 3    results
> 54787      0          54787      OK
> -          0          54787      OK
> 54787      -          0          OK
> 54787      0          -          OK
> -          -          0          OK
> -          0          -          OK
> -          -          0          OK

this is duplicate; the correct is:
   54787      -          -          !OK

> -          -          -          !OK
>
> So if any one alert is executed, we get results with the first click.
>
> Alert 1 always gives 54787.
>
> Alert 2 always gives 0.
>
> Alert 3 gives 54787 if alert 2 has execute before, otherwise it gives 0.
>
> We get results on the first click if any of the 3 alerts has been executed.
>
> Can anybody make sense out of this? I cannot.
>
> Eustace

Forget the other alerts. Just add 2 alerts before printing in the output 
area:

         if (bDay >= 0) {
alert(ephem.length);
alert(ephem.length);
           document.dataForm.outputArea.value +=
             "\n" + ephem[bDay][0] + " " + ephem[bDay][1] + " "
             + ephem[bDay][2];
         } else {
           document.dataForm.outputArea.value +=
           "\n" + "Invalid entry";
         }

The first will return 0 and the second 54787! Clearly the first alert 
restores the array. This should be a JavaScript bug.

If instead of these 2 alerts we introduce these 2:

alert(typeof(ephem[1]));
alert(typeof(ephem[1]));

they return undefined and object.

So far I have found 2 methods of restoring the array: Introducing an 
alert in a later function, or double=clicking the button.I am looking 
for a possible third way of bypassing the problem that does not require 
user intervention, though it seems I may have to settle with requesting 
the user to double-click the Find button.

emf

-- 
Google's top Spherical Triangle Calculator search result!
https://files.nyu.edu/emf202/public/js/spherical.html

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#22500

On 2013-12-28 15:12 emf wrote:
> On 2013-12-27 15:32 emf wrote:
>> On 2013-12-27 10:59 Evertjan. wrote:
>>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
>>>
>>>> On 2013-12-27 03:52 Evertjan. wrote:
>>>>> emf <emfril@gmail.com> wrote on 27 dec 2013 in comp.lang.javascript:
...
>
> Forget the other alerts. Just add 2 alerts before printing in the output
> area:
>
>          if (bDay >= 0) {
> alert(ephem.length);
> alert(ephem.length);
>            document.dataForm.outputArea.value +=
>              "\n" + ephem[bDay][0] + " " + ephem[bDay][1] + " "
>              + ephem[bDay][2];
>          } else {
>            document.dataForm.outputArea.value +=
>            "\n" + "Invalid entry";
>          }
>
> The first will return 0 and the second 54787! Clearly the first alert
> restores the array. This should be a JavaScript bug.
>
> If instead of these 2 alerts we introduce these 2:
>
> alert(typeof(ephem[1]));
> alert(typeof(ephem[1]));
>
> they return undefined and object.
>
> So far I have found 2 methods of restoring the array: Introducing an
> alert in a later function, or double=clicking the button.I am looking
> for a possible third way of bypassing the problem that does not require
> user intervention, though it seems I may have to settle with requesting
> the user to double-click the Find button.
>
> emf

The problem was corrected after I moved the loadFile() command right 
after the loadFile() function. It does make more sense this way.

emf

-- 
Natal Transits Calculator
https://files.nyu.edu/emf202/public/nt/nataltransits.html

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#22459

In comp.lang.javascript message <XnsA2A364854EA0Eeejj99@194.109.133.133>
, Fri, 27 Dec 2013 09:52:53, Evertjan. <exxjxw.hannivoort@inter.nl.net>
posted:

>function isValidDate(y, m, d) {
>   var t = new Date(y, m-1, d);
>   return t.getMonth()+1 == m  &&  t.getDate() == d;
>};


ISTM that the OP's argument d, originally two-decimal-digit, will
invariably have a numerical value in the inclusive range 0 to 99.  His
dates should be either reliably constructed with exactly 8 digits or
checked to have exactly 8 digits.

For which values of y, m, d is the getDate test beneficial?

<http://jibbering.com/faq/> section 5.2, statement with != .

Aside:  To the OP : only if Evertjan does not do it first.

-- 
 (c) John Stockton, nr London UK        Reply address via Merlyn Home Page.
   news:comp.lang.javascript FAQ <http://www.jibbering.com/faq/index.html>.
   <http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
   <http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.

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#22440 — XHR with timing issues (was: Compressing js file?)

emf wrote:

> The problem is that unless I un-comment the alert in the findBDay
> function, the first time I click on the button nothing happens because
> ephem hasn't yet be loaded. When I click the button a second time it
> works OK.

You'd better call open(..., ..., true) on the XHR object *after* you
have set the onreadystatechange property.

-- 
Christoph M. Becker

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#22444 — Re: XHR with timing issues (was: Compressing js file?)

Christoph Michael Becker wrote:

> emf wrote:
>> The problem is that unless I un-comment the alert in the findBDay
>> function, the first time I click on the button nothing happens because
>> ephem hasn't yet be loaded. When I click the button a second time it
>> works OK.
> 
> You'd better call open(..., ..., true) on the XHR object *after* you
> have set the onreadystatechange property.

How did you get *that* idea?  In some implementations, the call resets the 
property value.
 
-- 
PointedEars

Twitter: @PointedEars2
Please do not Cc: me. / Bitte keine Kopien per E-Mail.

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#22447 — Re: XHR with timing issues

Thomas 'PointedEars' Lahn wrote:

> Christoph Michael Becker wrote:
> 
>> emf wrote:
>>> The problem is that unless I un-comment the alert in the findBDay
>>> function, the first time I click on the button nothing happens because
>>> ephem hasn't yet be loaded. When I click the button a second time it
>>> works OK.
>>
>> You'd better call open(..., ..., true) on the XHR object *after* you
>> have set the onreadystatechange property.
> 
> How did you get *that* idea?  In some implementations, the call resets the 
> property value.

My bad -- I had intented to write:

You'd better call send() on an XHR object initialized with open(...,
..., true) *after* you have set the onreadystatechange property.

-- 
Christoph M. Becker

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#22448 — Re: XHR with timing issues

On 2013-12-28 06:08 Christoph Michael Becker wrote:
> Thomas 'PointedEars' Lahn wrote:
>
>> Christoph Michael Becker wrote:
>>
>>> emf wrote:
>>>> The problem is that unless I un-comment the alert in the findBDay
>>>> function, the first time I click on the button nothing happens because
>>>> ephem hasn't yet be loaded. When I click the button a second time it
>>>> works OK.
>>>
>>> You'd better call open(..., ..., true) on the XHR object *after* you
>>> have set the onreadystatechange property.
>>
>> How did you get *that* idea?  In some implementations, the call resets the
>> property value.
>
> My bad -- I had intented to write:
>
> You'd better call send() on an XHR object initialized with open(...,
> ..., true) *after* you have set the onreadystatechange property.

OK. though I did not have problems with it, but then I haven't yet 
started working on the web. -emf

-- 
Natal Transits Calculator
https://files.nyu.edu/emf202/public/jv/nataltransits.html

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#22441

emf wrote:
> [...]
 >
> The size of the ephemeris.js with only 2 planets is 1,606 KB. It
> includes the ephem array that is in the form:
>
> var ephem = [["19000101","27i43","10i08"], ["19000102","27i50","10i12"], ... ];
>
>  [...]
>
> My question is: Is there a way to make the data file smaller and still
> be able to read it with the JavaScript program?

++--------------------------------------++
||   saving bytes for "19000101" etc.   ||
++--------------------------------------++

[A]:
var ephem = [[19000101,"27i43","10i08"], [...
and replacing calls like
   x = ephem [n] [0]
with
   x = ephem [n] [0] . toString ()
should save ~ 6.5%.

[B]:
var ep_off = 19000000
var ephem = [[101,"27i43","10i08"], [...
and replacing calls like
   x = ephem [n] [0]
with
   x = ( ep_off + ephem [n] [0] ) . toString ()
should save more than 20%.

[C], assuming ephem [n] [0] always
      contains the date ( 1900/01/01 + n days ):
Replace calls like
   x = ephem [n] [0]
with
   x = ephem_func_0 ( n )
with an easy_to_write-function ephem_func_0.
You won't need the first column of ephem furthermore
and you will save ~ 35%.


++--------------------------------------------++
||   saving bytes for "27i43","10i08"" etc.   ||
++--------------------------------------------++

[A], imho a little dirty way to write code
      ( but sometimes done by me ):
var ephem = [19000101,"27i43","10i08", 19000102,...
Replace calls like
   x = ephem [n] [0]
   y = ephem [n] [m]  // m > 0
with
   x = ephem [n*3]
   y = ephem [n*3+m]
and save ~ 6.5%.

[B], imho a _very_ dirty way to write code:
var ephem = [19000101,"27i4310i08", 19000102,...
Replace calls like
   x = ephem [n] [0]
   y = ephem [n] [1]
   z = ephem [n] [2]
with
   x = ephem [n*2]  // or ephem [n<<1] to avoid multiplikation
   y = ephem [n*2+1] . substr ( 0 , 5 )
   z = ephem [n*2+1] . substr ( 5 , 5 )
and save ~ 16.5%.

[C]:
if ( you don't need all rows of ephem at once or
      you don't need all columns of ephem at once )
and there is an easy way to calculate ephem [n] [m]
replace calls like
   y = ephem [n] [m]  // m > 0
with
   y = ephem_func_m ( n )
and save a lot of bytes.

>
> Thanks,
>
> Eustace
>
> PS. I remember that last time I visited the newsgroup, more than 1 year
> ago, it was more active. Where have all the other programmers gone?
>

Regards, Wolfgang,

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#22445

On 2013-12-27 16:33 wolfgang zeidler wrote:
> emf wrote:
>> [...]
>  >
>> The size of the ephemeris.js with only 2 planets is 1,606 KB. It
>> includes the ephem array that is in the form:
>>
>> var ephem = [["19000101","27i43","10i08"],
>> ["19000102","27i50","10i12"], ... ];
>>
>>  [...]
>>
>> My question is: Is there a way to make the data file smaller and still
>> be able to read it with the JavaScript program?
>
> ++--------------------------------------++
> ||   saving bytes for "19000101" etc.   ||
> ++--------------------------------------++
>
> [A]:
> var ephem = [[19000101,"27i43","10i08"], [...
> and replacing calls like
>    x = ephem [n] [0]
> with
>    x = ephem [n] [0] . toString ()
> should save ~ 6.5%.
>
> [B]:
> var ep_off = 19000000
> var ephem = [[101,"27i43","10i08"], [...
> and replacing calls like
>    x = ephem [n] [0]
> with
>    x = ( ep_off + ephem [n] [0] ) . toString ()
> should save more than 20%.

Another idea is to omit the date altogether. And if I use csv instead,

[19000101,"27i43","10i08"],.  : 28 characters
becomes
27i43,10i08.   : 12 characters

which is about 57% reduction. Then I would subtract 1900-01-01 from the 
one entered to get the index of the array and avoid going through a loop.

I'll have to consider these and your other suggestions after I have 
given up on compressing the file. If I could compress it, I won't 
consider further reductions necessary.

Thanks,

Eustace

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#22446

emf <emfril@gmail.com> wrote on 28 dec 2013 in comp.lang.javascript:

> Another idea is to omit the date altogether. And if I use csv instead,
> 
> [19000101,"27i43","10i08"],.  : 28 characters
> becomes
> 27i43,10i08.   : 12 characters
> 
> which is about 57% reduction. Then I would subtract 1900-01-01 from the 
> one entered to get the index of the array and avoid going through a loop.
> 
> I'll have to consider these and your other suggestions after I have 
> given up on compressing the file. If I could compress it, I won't 
> consider further reductions necessary.

While I do not see much use in compression,
integer math is fun,
so if you want it, try to compress/decompress to/from base 36,
using the functions Javascript has in store,
toString() and parseInt():

<script type="text/javascript">

dateCompression(19130101);
dateCompression(20131228);

function dateCompression(d) {
		document.write(d + ' [original number]<br>');
	var substrac = 19500000;
	d = d - substrac;
	var dCompressed = d.toString(36).toUpperCase();
		document.write(dCompressed + ' [string base 36]<br>');
	var dNew = parseInt(dCompressed,36) + substrac;
		document.write(dNew + ' [reconstructed number]<br><br>');
};

</script>

The number dnew is in binary 
expressed as a decimal string by document.write(),
while the base 36 is a string by itself.

The inputparameter d can be a number or string, try:

dateCompression('19130101');

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#22450

On 2013-12-28 05:13 Evertjan. wrote:
> emf <emfril@gmail.com> wrote on 28 dec 2013 in comp.lang.javascript:
>
>> Another idea is to omit the date altogether. And if I use csv instead,
>>
>> [19000101,"27i43","10i08"],.  : 28 characters
>> becomes
>> 27i43,10i08.   : 12 characters
>>
>> which is about 57% reduction. Then I would subtract 1900-01-01 from the
>> one entered to get the index of the array and avoid going through a loop.
>>
>> I'll have to consider these and your other suggestions after I have
>> given up on compressing the file. If I could compress it, I won't
>> consider further reductions necessary.
>
> While I do not see much use in compression,
> integer math is fun,
> so if you want it, try to compress/decompress to/from base 36,
> using the functions Javascript has in store,
> toString() and parseInt():
>
> <script type="text/javascript">
>
> dateCompression(19130101);
> dateCompression(20131228);
>
> function dateCompression(d) {
> 		document.write(d + ' [original number]<br>');
> 	var substrac = 19500000;
> 	d = d - substrac;
> 	var dCompressed = d.toString(36).toUpperCase();
> 		document.write(dCompressed + ' [string base 36]<br>');
> 	var dNew = parseInt(dCompressed,36) + substrac;
> 		document.write(dNew + ' [reconstructed number]<br><br>');
> };
>
> </script>
>
> The number dnew is in binary
> expressed as a decimal string by document.write(),
> while the base 36 is a string by itself.
>
> The inputparameter d can be a number or string, try:
>
> dateCompression('19130101');

As I said elsewhere, eventually I may consider eliminating the date 
altogether. I am wondering, however, if I could compress the planetary 
positions, which can be expressed as integer minutes. (For example, 
17c22 equals (((c-a)*30) + 17) * 60 + 22, where c-a = 2.) How much could 
I save compressing these?

emf

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