gnuplot-py-users Mailing List for Gnuplot.py

Hi folks,

forgive me as I am new to gnuplot-py, but how can I pass dates as x data to=
 the=20
gnuplot.data function? When I try something like ["2004-10-05",10] the
module barfs and tells me that a float value is required.

Any help would be greatly appreciated!=20

cheers, uwe=20

From within python:=20

>>> data=3D[["2005-01-01", 20], ["2005-01-20", 19]]
>>> d=3DGnuplot.Data(data, with=3D'linespoints', using=3D'1:2')
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/lib/python2.3/site-packages/Gnuplot/PlotItems.py", line
513, in Data
    set =3D utils.float_array(set[0])
  File "/usr/lib/python2.3/site-packages/Gnuplot/utils.py", line 41,
in float_array
    return Numeric.asarray(m, Numeric.Float)
  File "/usr/lib/python2.3/site-packages/Numeric/Numeric.py", line
134, in asarray
    return multiarray.array(a, typecode, copy=3D0, savespace=3Dsavespace)
TypeError: a float is required

Hi

I have been trying to save plots generated using gnuplot-py to files that
can be read by the python imaging library (PIL), such as png, pbm. Every
time I try this I get the message:

" png does not support continuous colors"

I am using splot, pm3d, from within python on  a mac OSX_10.3.

I tried ' set palette maxcolors 100' but no luck.

Any ideas

Many thanks

mark
-- 
Dr Mark Thomas
Department of Biology
University College London
Gower Street
London WC1E 6BT
Tel:   (020) 7 679 2654
Fax:   (020) 7 679 7096
Mobile: 07973 725955
Email: m.t...@uc...
Web:   www.ucl.ac.uk/tcga/

Hi,

The problem is a little bit obscure.  You are passing splot() a 2-D 
array, but it really wants a 3-D array (the third axis would accomodate 
multiple data at each (x,y) point.  Probably this should be handled 
better, but a solution for you is to add a third axis explicitly:

     g.splot(a[..., N.NewAxis])

At least that works for me.

Michael

Mark Thomas wrote:
> I have been producing 2d arrays in python containing z values that I would
> like to plot then turn into animated gifs. Up until now I have been using
> gist (pli) to plot them. However, gist is very limited in the output file
> formats and I can't get any of the output file formats into for example
> Python Imaging Library in order to make animated gifs. So I decided to try
> drawing plots with Gnuplot in python. I have tried various examples that
> work in gnuplot but not when I try to put them into python.
> 
> An example is below (adapted from
> http://gnuplot.sourceforge.net/demo/pm3d.html):
> 
> 
> import Gnuplot
> import numarray as N
> g = Gnuplot.Gnuplot(debug=1)
> # set terminal png transparent nocrop enhanced font arial 8 size 420,320
> # set output 'pm3d.9.png'
> g('set border 4095 lt -1 lw 1.000')
> g('set view map')
> g('set samples 30, 30')
> #g('set isosamples 30, 30')
> g('unset surface')
> g('set style data pm3d')
> g('set style function pm3d')
> g('set ticslevel 0')
> g('set title "colour map, using default rgbformulae 7,5,15 ... traditional
> pm3d (black-blue-red-yellow)" 0.000000,0.000000  font ""')
> g('set xlabel "x" 0.000000,0.000000  font ""')
> g('set xrange [0:30] ')
> g('set ylabel "y" 0.000000,0.000000  font ""')
> g('set yrange [ 0:30]')
> g('set y2range [ * : * ] reverse nowriteback  # (currently
> [-10.0000:10.0000] )')
> g('set zrange [ 0.0001 : 1.00000 ] noreverse nowriteback')
> g('set pm3d at b')
> 
> 
> a = N.zeros([30,30]) +.3
> a[5:10,1:22] = .9
> g.splot(a)
> 
> Any thoughts would be greatly appreciated.

I have been producing 2d arrays in python containing z values that I would
like to plot then turn into animated gifs. Up until now I have been using
gist (pli) to plot them. However, gist is very limited in the output file
formats and I can't get any of the output file formats into for example
Python Imaging Library in order to make animated gifs. So I decided to try
drawing plots with Gnuplot in python. I have tried various examples that
work in gnuplot but not when I try to put them into python.

An example is below (adapted from
http://gnuplot.sourceforge.net/demo/pm3d.html):


import Gnuplot
import numarray as N
g = Gnuplot.Gnuplot(debug=1)
# set terminal png transparent nocrop enhanced font arial 8 size 420,320
# set output 'pm3d.9.png'
g('set border 4095 lt -1 lw 1.000')
g('set view map')
g('set samples 30, 30')
#g('set isosamples 30, 30')
g('unset surface')
g('set style data pm3d')
g('set style function pm3d')
g('set ticslevel 0')
g('set title "colour map, using default rgbformulae 7,5,15 ... traditional
pm3d (black-blue-red-yellow)" 0.000000,0.000000  font ""')
g('set xlabel "x" 0.000000,0.000000  font ""')
g('set xrange [0:30] ')
g('set ylabel "y" 0.000000,0.000000  font ""')
g('set yrange [ 0:30]')
g('set y2range [ * : * ] reverse nowriteback  # (currently
[-10.0000:10.0000] )')
g('set zrange [ 0.0001 : 1.00000 ] noreverse nowriteback')
g('set pm3d at b')


a = N.zeros([30,30]) +.3
a[5:10,1:22] = .9
g.splot(a)

Any thoughts would be greatly appreciated.

-- 
Dr Mark Thomas
Department of Biology
University College London
Gower Street
London WC1E 6BT
Tel:   (020) 7 679 2654
Fax:   (020) 7 679 7096
Mobile: 07973 725955
Email: m.t...@uc...
Web:   www.ucl.ac.uk/tcga/

Hi again, mailing list!!

After solving some problems thank to the help of Michael, I succeed with 
my proyect, but there is still a little detail that I can't find out. 
And this is: how to make the dates appear successfully on the screen. 
I'll explain:
    My x axis must print dates, and as the gnuplot tutorial sais, I've 
done something like this:
           


            $fp = popen("gnuplot -","w");
            fputs($fp,"set title \"".$ejey." de los 
telefonos:".$telefonos." desde: ".$limite_inferior." hasta: 
".$limite_superior." \"\n");
            fputs($fp,"set format y \"%.3f\"\n");
            fputs($fp,"set xlabel \"Fecha\"\n");
            fputs($fp,"set ylabel \"".$ejey."\"\n");
            fputs($fp,"set yrange [:]\n");
            fputs($fp,"set timefmt \"%Y-%m-%d %H:%M:%S\"\n");
            fputs($fp,"set xdata time\n");
            fputs($fp,"set format x \"%Y-%m-%d %H:%M\"\n");
            fputs($fp,"set ytics 0.25\n");
           // fputs($fp,"set xtics autofreq\n");
            fputs($fp,"set nomx2tics\n");
            fputs($fp,"set nomy2tics\n");
            fputs($fp,"set grid\n");
            fputs($fp,"set size 2\n");
            fputs($fp,"set lmargin 7\n");
            fputs($fp,"set rmargin 2\n");
            fputs($fp,"set tmargin 3\n");
            fputs($fp,"set bmargin 3\n");
            fputs($fp,"set boxwidth 10\n");
            fputs($fp,"set output 
\"/var/www/smtustat/salida_gnuplot.png\"\n");
            fputs($fp,"set terminal png\n");
            fputs($fp,$string_plot."\n");
          

And if the points that I'm sending to the program are from 2005-01-01 
00:00:00 to 2005-05-01 23:59:59, ..... why the x axis is divided into 
parts from 2000-01-01 00:00  to 2000-01-01 00:08?????
I've tried with everythin, tried to put xranges but it's useless, tried 
to change the order of the instructions but it's useless, and the really 
matter is that if dates don't appear correctly.... my proyect has no 
much sense.

Thank you very much if you can help me!!

Thank you all very much. I finally found that the problem was with 
"using" . This is the code with which my program works!

             $fp = popen("gnuplot -","w");
            fputs($fp,"set title \"".$ejey." de los telefonos: 
".$telefonos." desde: ".$limite_inferior." hasta: ".$limite_superior." 
\"\n");
            fputs($fp,"set format y \"%.3f\"\n");
            fputs($fp,"set xlabel \"Fecha\"\n");
            fputs($fp,"set ylabel \"".$ejey."\"\n");
            fputs($fp,"set yrange [:]\n");
            fputs($fp,"set timefmt \"%Y-%m-%d %H:%M:%S\"\n");
            fputs($fp,"set xdata time\n");
            fputs($fp,"set format x \"%Y-%m-%d %H:%M\"\n");
            fputs($fp,"set ytics 0.25\n");
            fputs($fp,"set xtics autofreq\n");
            //fputs($fp, "set xrange [\"".$limite_inferior."\" : 
\"".$limite_superior."\"\n");
            fputs($fp,"set nomx2tics\n");
            fputs($fp,"set nomy2tics\n");
            fputs($fp,"set grid\n");
            fputs($fp,"set size 2\n");
            fputs($fp,"set lmargin 7\n");
            fputs($fp,"set rmargin 2\n");
            fputs($fp,"set tmargin 3\n");
            fputs($fp,"set bmargin 3\n");
            fputs($fp,"set boxwidth 10\n");
            fputs($fp,"set output 
\"/var/www/smtustat/salida_gnuplot.png\"\n");
            fputs($fp,"set terminal png\n");
            fputs($fp,$string_plot."\n");
            for($i=0; $i<$total; $i++)

Do you know if there is any way to call from php to gnuplot, send all 
the points that I send... but not creating a file called 
"salida_gnuplot.png", but simply createn an image on the screen?? I am 
interested in this fact so that more than one user can have access to 
the file at the same time.
Thank you very much again! and I hope this little and simple code can 
help somebody.

See you!!

Hello people, I'm working with a simple php program. I'm suppossed to 
send some variables to gnuplot and wait for it to plot what I want. The 
problem is that I must be doing it really bad, since no plot appears at 
all. I'll explain better: I'm using the "exec" instruction, but I don't 
know how to tell my program that gnuplot must open. I directly write:
       
        exec(""set title \"Evolucion de las SMTU en el tiempo\"");
        exec("set format y \"%.3f\"");
        exec("set xlabel \"Fecha\"");
        exec("set ylabel ".$ejey);
        exec("set yrange [:]");
        exec("set xdata time");
        exec("set ytics 0.25");
        exec("set xtics");
        exec("set nomx2tics");
        exec("set nomy2tics");
        exec("set grid");
        exec("set size 2");
        exec("set lmargin 7");
        exec("set rmargin 2");
        exec("set tmargin 3");
        exec("set bmargin 3");
        exec("set boxwidth 10");
        exec("set output \"salida_gnuplot.png\"");
        exec("set terminal png");
           
        exec("plot '-' with linespoints, '-' with linespoints, '-' with 
linespoints);
            (and here, I star a bucle to send all the values like this:
               3
                4
                6
                0
.... and so on)

Another problem I have is that my xaxis is a date, and I don't 
understand very well how this structure of plot '-' works with dates.

No error message appears on my screen, but neither the plot appears.

thank you very much if you could help me!!

   

BBands wrote:

>I'd like to use the new xticlabels function. I have
>tried this:
>
>pData = Gnuplot.Data(date, open, high, low, close,
>using = '0:2:3:4:5:xticlabels(1)', with =
>'financebars')
>
>but gnuplot.py wants date to be a float.
>
>Any thoughts?
>  
>

Gnuplot.py doesn't know how to output dates.  And since it uses Numeric 
arrays to store data, it wouldn't be trivial to fix this for the general 
case.

So you probably need to write your data to a temporary file yourself 
(using a date format that can be understood by gnuplot), then plot the 
data directly from the file.

If you want to get fancier, then you can define a new PlotItem that 
knows how to output dates, then the whole Gnuplot.py infrastructure 
should simply work.

There was just a discussion on this mailing list about plotting dates.  
See the archives.

Michael

This is the well-known problem that the temporary files can be deleted 
before gnuplot is done using them.  Please see the first question of the 
FAQ.

Michael

Florian Lindner wrote:

>Hello,
>I've the python script:
>
>import Gnuplot
>
>g = Gnuplot.Gnuplot(debug=1)
>g.title('A simple example')
>g('set data style linespoints')
>g.plot([[0,1.1], [1,5.8], [2,3.3], [3,4.2]]
>
>taken from demo.py.
>
>When I try to execute:
>
>florian@horus ~/python $ python plot.py
>gnuplot> set title "A simple example"
>gnuplot> set data style linespoints
>gnuplot> plot '/tmp/tmpzCyAzN' notitle
>
>gnuplot> plot '/tmp/tmpzCyAzN' notitle
>              ^
>         can't read data file "/tmp/tmpzCyAzN"
>         line 0: util.c: No such file or directory
>
>
>What is wrong there?
>  
>

Hello,

I'd like to use the new xticlabels function. I have
tried this:

pData = Gnuplot.Data(date, open, high, low, close,
using = '0:2:3:4:5:xticlabels(1)', with =
'financebars')

but gnuplot.py wants date to be a float.

Any thoughts?

John

John Bollinger, CFA, CMT
www.BollingerBands.com

If you advance far enough, you arrive at the beginning.

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Sent another time, because the other mail didn't got through to the list after 
more than 2 hours.

Hello,
I've the python script:

import Gnuplot

g = Gnuplot.Gnuplot(debug=1)
g.title('A simple example')
g('set data style linespoints')
g.plot([[0,1.1], [1,5.8], [2,3.3], [3,4.2]]

taken from demo.py.

When I try to execute:

florian@horus ~/python $ python plot.py
gnuplot> set title "A simple example"
gnuplot> set data style linespoints
gnuplot> plot '/tmp/tmpzCyAzN' notitle

gnuplot> plot '/tmp/tmpzCyAzN' notitle
              ^
         can't read data file "/tmp/tmpzCyAzN"
         line 0: util.c: No such file or directory


What is wrong there?

Thx,

Florian

Hello,
I've the python script:

import Gnuplot

g = Gnuplot.Gnuplot(debug=1)
g.title('A simple example')
g('set data style linespoints')
g.plot([[0,1.1], [1,5.8], [2,3.3], [3,4.2]]

taken from demo.py.

When I try to execute:

florian@horus ~/python $ python plot.py
gnuplot> set title "A simple example"
gnuplot> set data style linespoints
gnuplot> plot '/tmp/tmpzCyAzN' notitle

gnuplot> plot '/tmp/tmpzCyAzN' notitle
              ^
         can't read data file "/tmp/tmpzCyAzN"
         line 0: util.c: No such file or directory


What is wrong there?

Thx,

Florian