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Re: Contour interpolated plot from scattered data

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On Friday, March 20, 2015 at 3:47:09 AM UTC-4, Karl wrote:
> Am 20.03.2015 um 03:01 schrieb ronsnetquest@gmail.com:
> > On Thursday, March 19, 2015 at 9:15:06 PM UTC-4, ronsne...@gmail.com wrote:
> >> On Thursday, March 19, 2015 at 6:40:52 PM UTC-4, ronsne...@gmail.com wrote:
> >>> On Thursday, March 19, 2015 at 6:05:23 PM UTC-4, ronsne...@gmail.com wrote:
> >>>> On Thursday, March 19, 2015 at 5:55:57 PM UTC-4, Karl wrote:
> >>>>> Am 19.03.2015 um 22:32 schrieb ronsnetquest@gmail.com:
> >>>>>> How do you do a color contour plot (map view) with interpolation
> >>>>>> between values from a data set when the values don't follow a
> >>>>>> consistent matrix?  The x axis is time (a date), the y axis is water
> >>>>>> depth (e.g., 0-20 meters), and the z value is water temperature
> >>>>>> (0-30C).
> >>>>>>
> >>>>>> The data is scattered enough that it cannot be put into a matrix
> >>>>>> usable by pm3d (AFAIK).  This is because the time values are not
> >>>>>> always consistently spaced and may have large gaps in them and there
> >>>>>> are some missing values here and there for water temperatures at
> >>>>>> various depths.
> >>>>>>
> >>>>>> Thanks much for any insight you can provide!
> >>>>>>
> >>>>>> Ron
> >>>>>>
> >>>>>
> >>>>> Have you tried "set dgrid3d"? I also has several options to control the
> >>>>> interpolation algorithm.
> >>>>>
> >>>>>   Karl
> >>>>
> >>>> No I hadn't.  But I see now that that may be what I was missing.  I'll keep working on it.  Thanks!
> >>>
> >>> OK, yes I have this working now!!  Thanks for the quick response.
> >>>
> >>> Ron
> >>
> >> Scratch that.  The dgrid3d interpolation will change the values themselves--not the missing values between the values which is what I need.
> > 
> > Here's my best attempt.  To simplify setting this up, I'm not using time data but a simple x value and some test data values.  If I do a simple plot:
> > 
> >     splot "test.dat" notitle
> > 
> > This looks fine.  But when I try to make this a color image, I can't get accurate results:
> > 
> >     splot "test.dat" using 1:2:3 with image notitle
> > 
> > Here's my best attempt:
> > 
> >     set xrange [0:10]
> >     set yrange [130:100]
> >     set xlabel "July"
> >     set ylabel "Depth (m)"
> >     set cblabel "Temperature (C)"
> >     set cbrange [0:30]
> > 
> >     set view map
> >     set hidden3d
> >     splot "test.dat" using 1:2:3 with image notitle
> > 
> 
> 
> The 2D plot "with image" seemingly ignores dgrid3d mode.
> 
> How about this?
> 
> (gnuplot 5.0 syntax, for older versions you have to plot the table to a
> temporary file instead of "$interpol")
> 
> set dgrid3d 20,30
> set table $interpol
> splot dataf using 1:2:3
> unset table
> 
> plot $interpol using 1:2:3 with image

Thanks, but dgrid3d doesn't do the type of interpolation that is needed.  I still haven't found a solution.

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Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-19 14:32 -0700
  Re: Contour interpolated plot from scattered data Karl <mail.kfr@gmx.net> - 2015-03-19 22:55 +0100
    Re: Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-19 15:05 -0700
      Re: Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-19 15:40 -0700
        Re: Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-19 18:15 -0700
          Re: Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-19 19:01 -0700
            Re: Contour interpolated plot from scattered data Karl <mail.kfr@gmx.net> - 2015-03-20 08:47 +0100
              Re: Contour interpolated plot from scattered data ronsnetquest@gmail.com - 2015-03-23 09:04 -0700

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