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How to do this?

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  How to do this? Ana Dionísio <anadionisio257@gmail.com> - 2013-04-01 03:14 -0700
    Re: How to do this? Vincent Vande Vyvre <vincent.vandevyvre@swing.be> - 2013-04-01 12:58 +0200
      Re: How to do this? Ana Dionísio <anadionisio257@gmail.com> - 2013-04-01 04:08 -0700
        Re: How to do this? Peter Otten <__peter__@web.de> - 2013-04-01 13:32 +0200
        Re: How to do this? Dave Angel <davea@davea.name> - 2013-04-01 07:53 -0400
      Re: How to do this? Ana Dionísio <anadionisio257@gmail.com> - 2013-04-01 04:08 -0700
    Re: How to do this? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-04-01 13:28 +0100

#42451 — How to do this?

So I have this script:

"
from numpy import array

vt=[0]*20
vt = array(vt, dtype=dict)

for t in range(20):
    if t == 4:
        vt[t]=1

    else:
        vt[t]=0
"

And have this output:

[0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

What I need is when t == 4 I need to put 1 in that position and in the next 3, for example the following output:

[0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0]

Do you have any suggestions?


I'm sorry if I can't explain this in a better way, English is not my first language

Thank you

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#42452

Le 01/04/13 12:14, Ana Dionísio a écrit :
> for t in range(20):
>     if t == 4:
>         vt[t]=1
Sets only the needed values:

for t in range(4, 8):
    vt[t]=1



-- 
Vincent V.V.
Oqapy <https://launchpad.net/oqapy> . Qarte
<https://launchpad.net/qarte> . PaQager <https://launchpad.net/paqager>

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#42453

Nice! Thank you!

And if I need something like this?

[0 0 0 0 0.17 0.17 0.17 0.17 0 0 0 0.17 0.17 0.17 0 0 0 0 0 0 0]

How can I do this?

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#42455

Ana Dionísio wrote:

> Nice! Thank you!
> 
> And if I need something like this?
> 
> [0 0 0 0 0.17 0.17 0.17 0.17 0 0 0 0.17 0.17 0.17 0 0 0 0 0 0 0]
> 
> How can I do this?

With vanilla Python:

>>> vt = [0] * 20
>>> for i, v in enumerate(vt):
...     if 4 <= i < 8 or 13 <= i < 16:
...             vt[i] = .17
... 
>>> vt
[0, 0, 0, 0, 0.17, 0.17, 0.17, 0.17, 0, 0, 0, 0, 0, 0.17, 0.17, 0.17, 0, 0, 
0, 0]

With vanilla Python using slices:

>>> vt = [0] * 20
>>> vt[4:8] = [.17]*4
>>> vt[13:16] = [.17]*3
>>> vt
[0, 0, 0, 0, 0.17, 0.17, 0.17, 0.17, 0, 0, 0, 0, 0, 0.17, 0.17, 0.17, 0, 0, 
0, 0]

With numpy:

>>> vt = numpy.zeros(20)
>>> vt[4:8] = vt[13:16] = .17
>>> vt
array([ 0.  ,  0.  ,  0.  ,  0.  ,  0.17,  0.17,  0.17,  0.17,  0.  ,
        0.  ,  0.  ,  0.  ,  0.  ,  0.17,  0.17,  0.17,  0.  ,  0.  ,
        0.  ,  0.  ])

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#42458

On 04/01/2013 07:08 AM, Ana Dionísio wrote:
> [0 0 0 0 0.17 0.17 0.17 0.17 0 0 0 0.17 0.17 0.17 0 0 0 0 0 0 0]


I'd do
res = "[0 0 0 0 0.17 0.17 0.17 0.17 0 0 0 0.17 0.17 0.17 0 0 0 0 0 0 0]"

Unless there's a pattern you're trying to accomplish (like maybe next 
time you want to do "it" for a list of two million items), there's 
little point in writing code to do what you've already predetermined. 
And if there is a pattern, you'd probably better let us know.

But if it's for fun,



vt = [0] * 21
for index, val in enumerate(vt):
     if 3<index<8 or 10<index<14:
         vt[index] = 0.17


or


vt = [0] * 21
for index, val in enumerate(vt):
     if index in (4,5,6,7,11,12,13):
         vt[index] = 0.17


-- 
-- 
DaveA

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#42454

Nice! Thank you!

And if I need something like this?

[0 0 0 0 0.17 0.17 0.17 0.17 0 0 0 0.17 0.17 0.17 0 0 0 0 0 0 0]

How can I do this?

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#42461

On 01/04/2013 11:14, Ana Dionísio wrote:
> So I have this script:
>
> "
> from numpy import array

Are you aware that this overrides the Python builtin array?  It's 
usually but not always better to do this

import numpy as np
vt = np.array(vt, dtype=dict)

>
> vt=[0]*20
> vt = array(vt, dtype=dict)
>
> for t in range(20):
>      if t == 4:
>          vt[t]=1
>
>      else:
>          vt[t]=0

Why the loop, you've already initialise the array to zeroes?

> "
>
> And have this output:
>
> [0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
>
> What I need is when t == 4 I need to put 1 in that position and in the next 3, for example the following output:
>
> [0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0]
>
> Do you have any suggestions?

Use slicing.
vt[4:8] = 1

>
>
> I'm sorry if I can't explain this in a better way, English is not my first language
>
> Thank you
>

-- 
If you're using GoogleCrap™ please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence

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