Re: heat map ?

[Ethan A M. <sf...@us...>]

On Friday, 22 April, 2016 18:43:10 Valerio Schiavoni wrote:
> Help everyone,
> following Ethan advice, i've tried to simply the .gp file. Now it looks
> like this:
> 
> set term pdfcairo
> set output "macrobench_latency_heat.pdf"
> load "../styles.inc"
> set size 0.9,1.0
> set lmargin 20
> set rmargin 20
> set palette defined (0.0 "white", 1.0 "blue")
> set tic scale 0
> set cblabel "Latency (ms)"
> set datafile separator comma
> plot\
>  "heatmap_latencies_handmade.txt" matrix rowheaders columnheaders u 1:2:3
> with image notable
> 
> Now, how do I show you the result ? I've uploaded it here
> http://postimg.org/image/sssos6q9j/full/
> but here, it shows it something that is completely different from the PDF
> that I see, in which the cells are smoothed/interpolated...for some reason..
> 
> Ideas?

The smoothing is probably happening in the program that you use to
view the pdf file.

Try adding the keyword "pixels":

     plot ... with image pixels

That will change the gnuplot output such that the viewer program
will probably not recognize it as something that can be smoothed.  
See for example the 5th plot in this set of examples

     http://gnuplot.sourceforge.net/demo_svg_5.1/heatmaps.html

	Ethan

> 
> --
> Valerio
> 
> 
> On Fri, Apr 22, 2016 at 5:50 PM, sfeam <sf...@us...> wrote:
> 
> > On Friday, 22 April 2016 09:46:50 AM Valerio Schiavoni wrote:
> > > Hello,
> > > i've been trying to make an heat map that looks like the one in this blog
> > > entry
> > > https://learnr.wordpress.com/2010/01/26/ggplot2-quick-heatmap-plotting/
> > > Unfortunately they don't use gnuplot.
> > >
> > > My attempt so far produces a poor result, i think because I'm not using
> > the
> > > right approach.
> > >
> > > Here's my current version:
> > >
> > > set term pdfcairo
> > > set output "latency_heat.pdf"
> > > load "../styles.inc"
> > > set size 0.9,1.0
> > > set lmargin 15
> > > set rmargin 20
> > > set pm3d #interpolate 0,100
> > > set view map scale 1
> > > set style func pm3d
> > > set style data pm3d;
> > > set dgrid3d
> > > set pal defined ( 0 0 0 0, 1 1 1 1 )
> > > set tic scale 0
> > > set cblabel "Latency (ms)"
> > > set datafile separator comma
> > > splot "heatmap_latencies.txt" matrix rowheaders columnheaders using 1:2:3
> > > with image title ""
> > >
> > > Where the input file is:
> > >
> > > ,One,Two,Three
> > > a,675.0, 1177.0, 1975.0
> > > b,744.0, 13908.0, 20191.0
> > > c,1767.0, 4374.0  ,5165.0
> > > d,678.0, 1101.0  ,1888.0
> > > e, 771.0, 13842.0 ,18648.0
> > > f, 1372.0, 4264.0  ,5187.0
> > > g,753.0 , 1541.0  ,1729.0
> > > h,791.0 , 5832.0  ,20528.0
> > > i,1310.0, 1225.0  ,5436.0
> > > l,747.0,  1516.0  ,2118.0
> > > m,825.0 , 16719.0 ,0
> > > n,1341.0, 4427.0 ,9040.0
> > >
> > >
> > > Any idea on how to improve this ?
> >
> > Most of those commands are irrelevant to what you want.
> > This is not a 3D surface, so you don't need "splot".
> > The colors are categorical, not smoothed, so you don't want pm3d.
> > Disregarding labels, it is sufficient to say
> >
> >   set datafile separator comma
> >   set palette defined (0.0 "white", 1.0 "blue")
> >   plot "heatmap_latencies.txt" matrix rowheaders columnheaders with image
> >
> >
> >         Ethan
> >