gnuplot-beta — Developers and beta testers of new gnuplot code

More efficient "dbl_raise"

[Daniel J S. <dan...@ie...>]

I've placed a patch on SourceForge that fixes a pathological example of range 
setting involving NaN.  Yes, I know, no big deal.  But, I've changed things to 
remove a routine for which Hans put forth the following question:

/* {{{ dbl_raise() used by quantize_normal_tics */
/* FIXME HBB 20000426: is this really useful? */
static double
dbl_raise(double x, int y)

The issue in dbl_raise is a multiplying loop for raising a value to an integer 
power.  I'm guessing the library function pow() does such a thing more 
efficiently in addition to handling the pathological NaN.  So, the following 
mimics the behavior of dbl_raise():

     exponent = floor(log(arg)/log(12.0));
     power = floor(pow(12.0, abs(exponent)) + 0.5);
     if (exponent < 0)
	power = 1.0 / power;
     /* approx number of "duodecades" */
     xnorm = arg / power;

The line of logic is that we know 10^E where E is a positive integer is an 
integer value, therefore rounding to the nearest integer should remove any 
arithmetic precision error that pow() might introduce.

That fixes the original issue I had in mind.  And I've generated all.dem output 
in PostScript format.  Everything agrees, except the dates and times inside the 
PS files.

In some way it also removes the question that Hans raised in the code.  I'm sure 
you can't recall that far back, Hans, but a question I have is just exactly was 
this approach supposed to achieve?  I'm assuming it had something to do with 
nice tic range generation.  But at the same time I wonder if there isn't a more 
straightforward computation.

One thing I wonder about is the following.  Say I modify the above code to be:

     /* order of magnitude of argument: */
     exponent = floor(log(arg)/log(12.0));
     power = floor(pow(12.0, abs(exponent)) + 0.5);
     /* approx number of "duodecades" */
     if (exponent < 0)
	xnorm = arg * power;
     else
	xnorm = arg / power;

Wouldn't you think that this is a better formulation in terms of precision? 
That is, we've a direct division in one case, and avoid a double division in 
another case.  But if I run this version of gnuplot on all.dem, the result is 
differences other than just the times and dates.  So which is the preferred 
result formulation?

Dan

Re: 4D data missing

[Daniel J S. <dan...@ie...>]

Daniel J Sebald wrote:
> I was just checking all.dem.  There is a 4D data demo for which there seems to 
> be no data.  I've done a "make all" in the demo directory and still nothing 
> appears.  Was a file not checked into the CVS version?

Oops, I'm wrong on that one.  4D-data.dem is the name of the file, whereas this 
is spelled "4D_data.dem" inside all.dem.

Dan

4D data missing

[Daniel J S. <dan...@ie...>]

I was just checking all.dem.  There is a 4D data demo for which there seems to 
be no data.  I've done a "make all" in the demo directory and still nothing 
appears.  Was a file not checked into the CVS version?

Dan

Re: May I translate Gnuplot - programm - to portuguese ?

[<tim...@en...>]

> I would like to translate Gnuplot (the commands and the Help) to
> portuguese. May I do that ?
>
> If I can, can I have some help to start with (a road map to the programm
> so I can see here from to make the firsts changes).
> I have download the source, from the CVS repository.
>
> Thanks for your attention,
>
> Tarcisio
> tar...@me...

Hi Tarcisio,

Thanks for your interest in gnuplot. A translation in Portuguese will
undoubtedly be welcome.
As far as the help is concerned, the source file is docs/gnuplot.doc. For
example, gnuplot.doc has been translated in japanese, it's the file
gnuplot-ja.doc
However, gnuplot doesn't have any framework to translate the commands
messages. If you want to take a look at existing solutions to do that, it
will appreciated too. I am especially thinking of gettext.

Best regards,

Timothée Lecomte

Re: ANN: Gnuplot Web Interface, a simple demo for how to use gnuplot in an interactive way on a web page

[Thomas H. <tph...@gm...>]

The money page seems to be at:

http://skuld.bmsc.washington.edu/scatter/AS_form.html

Very interesting. I'm reading more about how this works, while I try
to determine if there's any thing new in my approach, or if basically
the above-linked project covers it all.

2007/3/28, Ethan A Merritt <merritt@u.washington.edu>:
> On Wednesday 28 March 2007 07:27, Thomas Hartman wrote:
> > Gnuplotters, I cooked up a simple demo for using gnuplot in a web
> > page, and pushed the source out to google project hosting in case this
> > could be useful to anyone.
>
> See also:
>
>         http://www.bmsc.washington.edu/people/merritt/gnuplot_test.html
>
> > If anyone has ideas on how this could be improved and/or would like
> > repo commit to add their own refinements, please let me know and I
> > will be glad to accomodate.
> >
> > Also, I am a newcomer to the gnuplot scene, so let me know if it would
> > be appropriate to post this to other mailing lists.
> >
> > Demot: http://64.22.71.11/gnuplot/gnuplot.html
> > Source:: http://code.google.com/p/gnuplotwebinterface/
> >
> > Enjoy!
> >
> > Thomas.
> >
> > -------------------------------------------------------------------------
> > Take Surveys. Earn Cash. Influence the Future of IT
> > Join SourceForge.net's Techsay panel and you'll get the chance to share your
> > opinions on IT & business topics through brief surveys-and earn cash
> > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
> > _______________________________________________
> > gnuplot-beta mailing list
> > gnu...@li...
> > https://lists.sourceforge.net/lists/listinfo/gnuplot-beta
> >
>
> --
> Ethan A Merritt
> Biomolecular Structure Center
> University of Washington, Seattle 98195-7742
>

Re: ANN: Gnuplot Web Interface, a simple demo for how to use gnuplot in an interactive way on a web page

[Ethan A M. <merritt@u.washington.edu>]

On Wednesday 28 March 2007 07:27, Thomas Hartman wrote:
> Gnuplotters, I cooked up a simple demo for using gnuplot in a web
> page, and pushed the source out to google project hosting in case this
> could be useful to anyone.

See also:

	http://www.bmsc.washington.edu/people/merritt/gnuplot_test.html
 
> If anyone has ideas on how this could be improved and/or would like
> repo commit to add their own refinements, please let me know and I
> will be glad to accomodate.
> 
> Also, I am a newcomer to the gnuplot scene, so let me know if it would
> be appropriate to post this to other mailing lists.
> 
> Demot: http://64.22.71.11/gnuplot/gnuplot.html
> Source:: http://code.google.com/p/gnuplotwebinterface/
> 
> Enjoy!
> 
> Thomas.
> 
> -------------------------------------------------------------------------
> Take Surveys. Earn Cash. Influence the Future of IT
> Join SourceForge.net's Techsay panel and you'll get the chance to share your
> opinions on IT & business topics through brief surveys-and earn cash
> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
> _______________________________________________
> gnuplot-beta mailing list
> gnu...@li...
> https://lists.sourceforge.net/lists/listinfo/gnuplot-beta
> 

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742

ANN: Gnuplot Web Interface, a simple demo for how to use gnuplot in an interactive way on a web page

[Thomas H. <tph...@gm...>]

Gnuplotters, I cooked up a simple demo for using gnuplot in a web
page, and pushed the source out to google project hosting in case this
could be useful to anyone.

There is functionality for creating 2d graphs, 3d graphs, and
financial data. It's very basic, ~ 300 LOC including the html form; I
just wanted to get something out there.

If anyone has ideas on how this could be improved and/or would like
repo commit to add their own refinements, please let me know and I
will be glad to accomodate.

Also, I am a newcomer to the gnuplot scene, so let me know if it would
be appropriate to post this to other mailing lists.

Demot: http://64.22.71.11/gnuplot/gnuplot.html
Source:: http://code.google.com/p/gnuplotwebinterface/

Enjoy!

Thomas.

help fails after load pipe

[Shigeharu T. <sh...@ie...>]

shige 03/27 2007
----------------

After the load command with pipe

 load "< some_command"

help command may fail. For example, in the case PAGER=less, 

 gnuplot> load "< awk 'BEGIN{print \"print 3\"}'"
 3
 gnuplot> help
 Missing filename ("less -\?" for help)
 Help topic: 

Environment:

 OS: Solaris 9 (sparc)
 gnuplot: 4.2.0, 4.3 (Feb.2007) 
   (config.h: #define PIPES 1, #define PIPE_IPC 1)

+========================================================+
 Shigeharu TAKENO     NIigata Institute of Technology
                       kashiwazaki,Niigata 945-1195 JAPAN
 sh...@ie...   TEL(&FAX): +81-257-22-8161
+========================================================+

Re: Delete files after use possible?

[Daniel J S. <dan...@ie...>]

Petr Mikulik wrote:

> That's exactly how I do it in Octave, e.g.
> 
> tmpfile=tmpnam;
> savegpbin(x, y, z, tmpfile);
> gpbin2png(out_file, tmpfile);
> graw( sprintf("!rm -f %s\n", tmpfile) );
> 
> But note that you cannot do "replot".

Good point, but I don't think it will matter much in Octave's new setup as data 
is redone each time a plot is redrawn.  Not sure.

Dan

Re: Delete files after use possible?

[Petr M. <mi...@mo...>]

> >> Is it possible, or would it be a useful feature for gnuplot to have a 
> >> datafile mode setting for which data files are deleted after they have 
> >> been read and are no longer required for gnuplot's use?  
> >
> > So what exactly is keeping them from issuing a "! rm file" into 
> > gnuplot's command queue directly after the "plot" command?

That's exactly how I do it in Octave, e.g.

tmpfile=tmpnam;
savegpbin(x, y, z, tmpfile);
gpbin2png(out_file, tmpfile);
graw( sprintf("!rm -f %s\n", tmpfile) );

But note that you cannot do "replot".

---
PM

Re: Delete files after use possible?

[Daniel J S. <dan...@ie...>]

Hans-Bernhard Bröker wrote:
> Daniel J Sebald wrote:
> 
>> Is it possible, or would it be a useful feature for gnuplot to have a 
>> datafile mode setting for which data files are deleted after they have 
>> been read and are no longer required for gnuplot's use?  
> 
> 
> So what exactly is keeping them from issuing a "! rm file" into 
> gnuplot's command queue directly after the "plot" command?

Ah, interesting.  Not sure that is portable, but I will toss that idea to the 
discussion list.  Thanks.

Dan

Delete files after use possible?

[Daniel J S. <dan...@ie...>]

Is it possible, or would it be a useful feature for gnuplot to have a datafile 
mode setting for which data files are deleted after they have been read and are 
no longer required for gnuplot's use?  A complaint from someone using Octave was 
that temporary image files used to send data to gnuplot were hanging around 
until the app exits and that disk space ran out.  There are options available 
now to put all data through the pipe so that files are no longer necessary, but 
I'm still inquiring if generally speaking it would be good to have such a thing, 
e.g.,

set datafile discard
set datafile temporary

?

I guess another approach is for the app to somehow wait on gnuplot finishing 
it's plot request.  Should that be the preferred use?

Dan

May I translate Gnuplot - programm - to portuguese ?

[tarcisio praciano-p. <pra...@gm...>]

I would like to translate Gnuplot (the commands and the Help) to 
portuguese. May I do that ? 

If I can, can I have some help to start with (a road map to the programm
so I can see here from to make the firsts changes).
I have download the source, from the CVS repository.

Thanks for your attention,

Tarcisio
tar...@me...

Re: Loop into parametric plot or splot

[Brouard N. <br...@in...>]

Le lundi 19 mars 2007 à 03:42 -0600, Daniel J Sebald a écrit : 
> Brouard Nicolas wrote:
> > Hi,
> > I have been subscribed to gnuplot-dev some years ago and you could find
> > my name in old archives concerning a patch on logscale (if I remember
> > well).
> > 
> > I am back to your gnuplot-beta list, because I discovered your new gif
> > animated function in 4.2 and 4.3 (I made a Mandriva rpm of your latest
> > snapshot for my own use but I will submit it to Cooker soon if you don't
> > see any objection).
> > 
> > You can have a look at the animations that I did for Wikipedia at
> > http://commons.wikimedia.org/wiki/Image:Foucault-anim.gif but also at
> > http://commons.wikimedia.org/wiki/Image:Foucault-rotz.gif . You can get
> > the gnuplot sources in the description of theses pages. Any hint to
> > improve the drawings? 
> > 
> > Also the mathematics are in fr.wikipedia.org/wiki/Pendule_de_Foucault
> > but the size of the second drawing is too big (for the memory of
> > commons, see http://bugzilla.wikimedia.org/show_bug.cgi?id=2888) and
> > can't be processed easily. Another Wikipedian used Gimp in order to
> > decrease the size of it and got a thumb, but now I uploaded a newer
> > version and the thumb can't get through. Any hint to play with lower
> > number of colors and reduced indexed colors.
> 
> Try
> 
>    gifsicle -O Foucault-anim.gif > anim.gif
> 
> which will reduce the color table from 256 to 16.  (You may use
> 
>    gifsicle --info Foucault-anim.gif
>    gifsicle --info anim.gif
> 
> to verify this.  It reduces the file by maybe 5 to 10%.
> 
> What you will also see in the info is the size of successive images in the 
> animation.  Although not much changes from frame to frame in your demo, GIF 
> works with subimages so has to include the whole subimage that includes all 
> parts of the image that change.

Sorry for my late reply.
The most memory consuming animated gif file is the second
http://commons.wikimedia.org/wiki/Image:Foucault-rotz.gif 
where the view is from the oscillation plane (using a rotating set
view).

Thank you for the information on gifsicle. I don't know why ungifsicle
is still distributed (by Mandriva for example) because the LZH patent is
out now.

Using 

   gifsicle -O2 -k8 foucault-rotz.gif -o foucault-rotz-O2-k8.gif

gives a 8.3% smaller output file from 426182 bytes to 390847 bytes.

But for the static view (anim.gif) the reduction is 43% from 232333 to
133267.

In both cases the terminal is open with:
set ter gif animate optimize size 640,480  xffffff x000000 xa0a0a0
xff0000 x00c000 x0080ff xc000ff x00eeee;

I don't know exactly what influences this reduction and its so varying
factor (from 8.3% to 43%).

Adding the crop terminal option for the '-anim.gif' gives a mostly left
shifted image (cropped) which is only slightly smaller, from  232333 to
231954 bytes because the left part of the image is white.

For the '-rotz' image, the crop option doesn't work as it should (I
think): all frames ares left shifted (cropped) but their centers are not
translated back correctly. I think that the crop option in an animated
gif should crop the outmost largest image and centered them, for example
like gifsicle does with its --crop 100,10+-Ox-0 option.

Any hint on what gnuplot part of the sources I should look to fix this?

For example, here are the first lines of the output of the command
> gifsicle --info foucault-rotz.gif
 foucault-rotz.gif 72 images
  logical screen 640x480
  global color table [256]
  background 0
  loop forever
  + image #0 640x480
    disposal asis delay 0.10s
  + image #1 472x456 at 127,6
    disposal asis delay 0.10s
  + image #2 470x456 at 128,6
    disposal asis delay 0.10s
  + image #3 468x455 at 129,6
    disposal asis delay 0.10s
  + image #4 468x455 at 129,6
    disposal asis delay 0.10s
  + image #5 466x454 at 130,6
 
in order to see how each frame is shifted from the biggest first #0
640x480 frame: frame #5 top left corner is 130 right and 6 pixels lower
than top corner of frame #0, but frame #2 is only 127 right, in order to
keep the same center (equilibrium of the pendulum and coordinates 0,0,0
of gnuplot) at the same position of the screen when the system is
rotating and image growing or shrinking.


>Nice demo though.

You can access to the Gnuplot code of the drawing at
http://commons.wikimedia.org/wiki/Image:Foucault-rotz.gif . It is
licensed under GPL in order to be improved by anyone who wants to. The
image itself is under FGDL and CC, but I would like that more and more
scientific figures from Wikipedia are reproductible and thus move from
'Art' to 'Science'. I don't know which licence is the most appopriate
for Gnuplot drawings but I suggested GPL. Any opinion?

Regards,

Nicolas




> Nice demo though.
> 
> Dan

Re: gnu plot doc links fail

[Ethan A M. <merritt@u.washington.edu>]

On Wednesday 21 March 2007 20:19, Colin Dick wrote:
> hi guys
> 
> on this page
> http://gnuplot.sourceforge.net/documentation.html
> 
> ALL the links fail for
> Official gnuplot reference card and tutorial

Thanks.  
I've placed a copy of the version 4.2 tutorial.pdf and tutorial.ps.gz 
in that directory.

It seems that no one has updated gpcard for 4.2
Any volunteers?

-- 
Ethan A Merritt

gnu plot doc links fail

[Colin D. <col...@ho...>]

hi guys

on this page
http://gnuplot.sourceforge.net/documentation.html

ALL the links fail for
Official gnuplot reference card and tutorial

they give this error message
An error has been encountered in accessing this page.

1. Server: gnuplot.sourceforge.net
2. URL path: /docs/gpcard.pdf
3. Error notes: File does not exist: 
/home/groups/g/gn/gnuplot/htdocs/docs/gpcard.pdf
4. Error type: 404
5. Request method: GET
6. Request query string:
7. Time: 2007-03-21 20:14:24 PDT (1174533264)

thanx

_________________________________________________________________
Live Search delivers results the way you like it. Try live.com now! 
http://www.live.com

Re: Loop into parametric plot or splot

[Ethan M. <merritt@u.washington.edu>]

On Sunday 18 March 2007 13:41, Brouard Nicolas wrote:
> Trying to still improve the drawings I tested your for loop, but in
> parametrics mode something like:
>    plot [t=0:2.*pi] for[i=0:2] sin(t+i),t
> will give strange results (not stupid result) and something like
>    plot [t=0:2.*pi] for[i=1:2] sin(t+i),t
> outputs a warning
>   parametric function not fully specified

Hmm. Yes, I can believe that.
Both of my recent plot extensions (iteration and '+' as a pseudo-file)
came with a caveat that I wasn't familiar enough with the parametric
plot modes to test them thoroughly.

The problem is poorly chosen syntax for parametric plots, syntax
that we are now stuck with even though it is a pain to parse correctly.
In "normal" plot commands a comma indicates the end of one plot and 
the beginning of another.  In parametric plot commands the comma means
something else entirely.  The iteration code is not smart enough to
distinguish the two cases.  Fixing this will probably be a headache,
but I'm sure it's possible.


-- 
Ethan A Merritt

Possible 4.2 release branch bug fix

[Daniel J S. <dan...@ie...>]

I placed a simple patch on SourceForge to fix a bug from a change on 2007-02-25 
in which setup_tics() was moved from inside the colorbox routine to plot3d.c. 
The oversight is that graphics.c also needs such a call if the routine is 
removed from colorbox draw.  (This is a case where some unification of 2D/3D 
layout similarities would have obviated such oversights.)

Please consider moving that bug fix into the 4.2 branch updates if that is what 
is being done for 4.2.

Dan

Re: Loop into parametric plot or splot

[Daniel J S. <dan...@ie...>]

Brouard Nicolas wrote:
> Hi,
> I have been subscribed to gnuplot-dev some years ago and you could find
> my name in old archives concerning a patch on logscale (if I remember
> well).
> 
> I am back to your gnuplot-beta list, because I discovered your new gif
> animated function in 4.2 and 4.3 (I made a Mandriva rpm of your latest
> snapshot for my own use but I will submit it to Cooker soon if you don't
> see any objection).
> 
> You can have a look at the animations that I did for Wikipedia at
> http://commons.wikimedia.org/wiki/Image:Foucault-anim.gif but also at
> http://commons.wikimedia.org/wiki/Image:Foucault-rotz.gif . You can get
> the gnuplot sources in the description of theses pages. Any hint to
> improve the drawings? 
> 
> Also the mathematics are in fr.wikipedia.org/wiki/Pendule_de_Foucault
> but the size of the second drawing is too big (for the memory of
> commons, see http://bugzilla.wikimedia.org/show_bug.cgi?id=2888) and
> can't be processed easily. Another Wikipedian used Gimp in order to
> decrease the size of it and got a thumb, but now I uploaded a newer
> version and the thumb can't get through. Any hint to play with lower
> number of colors and reduced indexed colors.

Try

   gifsicle -O Foucault-anim.gif > anim.gif

which will reduce the color table from 256 to 16.  (You may use

   gifsicle --info Foucault-anim.gif
   gifsicle --info anim.gif

to verify this.  It reduces the file by maybe 5 to 10%.

What you will also see in the info is the size of successive images in the 
animation.  Although not much changes from frame to frame in your demo, GIF 
works with subimages so has to include the whole subimage that includes all 
parts of the image that change.

Nice demo though.

Dan

Loop into parametric plot or splot

[Brouard N. <br...@in...>]

Hi,
I have been subscribed to gnuplot-dev some years ago and you could find
my name in old archives concerning a patch on logscale (if I remember
well).

I am back to your gnuplot-beta list, because I discovered your new gif
animated function in 4.2 and 4.3 (I made a Mandriva rpm of your latest
snapshot for my own use but I will submit it to Cooker soon if you don't
see any objection).

You can have a look at the animations that I did for Wikipedia at
http://commons.wikimedia.org/wiki/Image:Foucault-anim.gif but also at
http://commons.wikimedia.org/wiki/Image:Foucault-rotz.gif . You can get
the gnuplot sources in the description of theses pages. Any hint to
improve the drawings? 

Also the mathematics are in fr.wikipedia.org/wiki/Pendule_de_Foucault
but the size of the second drawing is too big (for the memory of
commons, see http://bugzilla.wikimedia.org/show_bug.cgi?id=2888) and
can't be processed easily. Another Wikipedian used Gimp in order to
decrease the size of it and got a thumb, but now I uploaded a newer
version and the thumb can't get through. Any hint to play with lower
number of colors and reduced indexed colors.

Trying to still improve the drawings I tested your for loop, but in
parametrics mode something like:
   plot [t=0:2.*pi] for[i=0:2] sin(t+i),t
will give strange results (not stupid result) and something like
   plot [t=0:2.*pi] for[i=1:2] sin(t+i),t
outputs a warning
  parametric function not fully specified

Many thanks for any answer.

Nicolas

Re: On ranges in gnuplot

[Lutz M. <ma...@be...>]

Dear Andrey,

I believe the features you are proposing might already be available in 
gnuplot, albeit with a less concise syntax.

On Saturday 17 March 2007 11:40, Andrey V. Komolkin wrote:
> First. In the "plot" command I propose to allow to setup range of 'x'
> (independent) variable to each of functions/files. For instance:
>
> set xrange [0:10]
> plot sin(x), cos(x) range [1:9], 'file.dat' range [1:9] with lines

This can be done using

set xrange [0:10]
plot sin(x), (x >= 1 && x <= 9 ? cos(x) : 1/0), 'file.dat' using 1:($1 >= 1 
&& $1 <= 9 ? $2 : 1/0) with lines

(This assumes that file.dat contains rows of (x,y) pairs. If instead it 
contains rows of single numbers, replace $1 by $0 and $2 by $1).

> Imagine, the data we like to approximate have two parts:
>
> f1(x)=a*x+b
> fit [0:5] f1(x) 'file.dat' via a,b
> f2(x)=c*x+d
> fit [6:10] f2(x) 'file.dat' via c,d
> set xr [0:10]
> plot 'file.dat' w p, [0:5] f1(x), [6:10] f2(x)

Try

plot 'file.dat' w p, (x >= 0 && x <= 5 ? f1(x) : 1/0), (x >= 6 && x <= 10 ? 
f2(x) : 1/0)

> Second. Let me propose "dashed" ranges: [0:10,20:30]. This feature may
> be useful for approximation of experimental data.

> t(x)=a*x+b
> fit [*:-5,5:*] t(x) 'file.dat' via a,b
> set xr [-10:10]
> plot t(x) range [-10:-5,5:10], 'file.dat' with points

t(x)=a*x+b
fit t(x) 'file.dat' using 1:($1 < -5 || $1 > 5 ? $2 : 1/0) via a,b
set xr [-10:10]
plot (x < -5 || x > 5 ? t(x) : 1/0), 'file.dat' with points

You can find the details in "help using" and "help ternary".

Hope this helps, 

  Lutz

On ranges in gnuplot

[Andrey V. K. <kom...@es...>]

Dear colleagues,

I am frequent user and enthusiast of "gnuplot", but not a developer. Let 
me propose some new features for the program. I hope these are new, 
because I did not find any references to such features in documentation 
for new version 4.3.

---------------

First. In the "plot" command I propose to allow to setup range of 'x' 
(independent) variable to each of functions/files. For instance:

set xrange [0:10]
plot sin(x), cos(x) range [1:9], 'file.dat' range [1:9] with lines

In this example, sin(x) should be shown in range [0:10], but cos(x) and 
data from 'file.dat' in different ranges, which are set individually for 
these graphs. This may be useful in the case we like to plot tabulated 
data and its approximation (analytical function) in the same plot.

Imagine, the data we like to approximate have two parts:

f1(x)=a*x+b
fit [0:5] f1(x) 'file.dat' via a,b
f2(x)=c*x+d
fit [6:10] f2(x) 'file.dat' via c,d
set xr [0:10]
plot 'file.dat' w p, [0:5] f1(x), [6:10] f2(x)

I do not like to plot analytical function f1(x) outside the range [0:5], 
where it was fitted and (in general) defined. And vice versa, f2(x) was 
defined in range [6:10]...

-----------------

Second. Let me propose "dashed" ranges: [0:10,20:30]. This feature may be 
useful for approximation of experimental data.

Imagine, experimental data g(x) contains several peaks f(x) on the 
"basement" -0.02*x+1.0. We need to remove trend (-0.02*x+1.0) from the 
data.

set xr [-10:10]
set yr [0:7]
f(x,a,x0,dx)=a*exp(-(x-x0)**2/dx**2)
g(x)=f(x,5,1,1)+f(x,2,-3,0.5)+1.0-0.02*x

This trend can not be determined on the whole range [-10:10],
but on two ends of the range:

t(x)=a*x+b
fit [*:-5,5:*] t(x) 'file.dat' via a,b
set xr [-10:10]
plot t(x) range [-10:-5,5:10], 'file.dat' with points

------------------

Conclusion. I proposed in this letter two new features for the 'gnuplot'.

First: separate ranges for each functions/files in 'plot' command

Second: "dashed" ("united" or however it will be called) ranges which 
consist of several (two, three or even more) subranges.

------------------

I like to receive comments on my proposals.

Best wishes,

Andrei Komolkin.
======================================================================
Dr. Andrei V. Komolkin
Senior Lecturer (University Reader)

V. A. Fock Institute of Physics       Tel.:   +7-(812)-428-44-79
Saint-Petersburg State University     Fax:    +7-(812)-428-72-40
198504, Saint-Petersburg              E-mail: kom...@es...
Russia

Re: piping stdin to gnuplot to postscript viewer --one way works, the other doesn't. is this a bug?

[Ethan M. <merritt@u.washington.edu>]

On Friday 16 March 2007 08:00, Thomas Hartman wrote:
> I have two commands, that it seems to me should have the same result:
> a plot is opened with a postscript viewer.
> 
> However, with one way the postscript output can be read, and with the
> other it can't.
> 
> I also show the diff of the output below.
> 
> Is this as it should be, or a bug?

Incorrect command issued from the bash prompt.
This would have worked from csh/tcsh but you need to be more careful
if you are using bash.

Your command:

  cat save-sin.plt | gnuplot - > out-bad.ps

Correct command:

  cat save-sin.plt | gnuplot > out-good.ps

Note the important difference:

  If gnuplot sees "-" in the command line, it enters interactive mode
  and issues user prompts on stderr.  Your bash command redirects both
  the user prompts (stderr) and the plot (stdout) into a file.


> hartman@ds0207:~/learning/gnuplot>cat make-out-bad.sh
> #!/bin/bash
> outfile=out-bad.ps
> rm -f $outfile
> ( cat save-sin.plt | gnuplot - ) > out-bad.ps;
> kghostview $outfile;
> #rm $outfile
> 
> hartman@ds0207:~/learning/gnuplot>cat make-out-good.sh
> #!/bin/bash
> outfile=out-good.ps
> rm -f $outfile
> ( gnuplot save-sin.plt ) > $outfile;
> kghostview $outfile;
> #rm $outfile
> 
> hartman@ds0207:~/learning/gnuplot>cat save-sin.plt
> # File name: save.plt - save a Gnuplot plot as a PostScript file
> set terminal postscript portrait enhanced mono dashed lw 1 "Helvetica" 14
> plot sin(x)
> 
> hartman@ds0207:~/learning/gnuplot>./compare-out-good-out-bad.sh
> Terminal type set to 'postscript'
> Options are 'portrait enhanced monochrome blacktext \
>    dashed dashlength 1.0 linewidth 1.0 defaultplex \
>    palfuncparam 2000,0.003 \
>    butt "Helvetica" 14'
> 
> 1c1
> < gnuplot> gnuplot> gnuplot> %!PS-Adobe-2.0
> ---
> > %!PS-Adobe-2.0
> 3c3
> < %%CreationDate: Fri Mar 16 15:49:56 2007
> ---
> > %%CreationDate: Fri Mar 16 15:49:54 2007
> 638c638
> < gnuplot> %%Trailer
> ---
> > %%Trailer

-- 
Ethan A Merritt            Courier Deliveries: 1959 NE Pacific
Dept of Biochemistry
Health Sciences Building
University of Washington - Seattle WA 98195-7742

piping stdin to gnuplot to postscript viewer --one way works, the other doesn't. is this a bug?

[Thomas H. <tph...@gm...>]

I have two commands, that it seems to me should have the same result:
a plot is opened with a postscript viewer.

However, with one way the postscript output can be read, and with the
other it can't.

I also show the diff of the output below.

Is this as it should be, or a bug?

I'd like to be able to do something like what I attempted in
make-out-bad.sh, eg, hook up gnuplot to an arbitrary source of input,
and then pipe it out to wherever. Otherwise, I'm stuck feeding gnuplot
files, can't use arbitrary stdin under all circumstances.

***********************

hartman@ds0207:~/learning/gnuplot>gnuplot --version
gnuplot 4.0 patchlevel 0

hartman@ds0207:~/learning/gnuplot>cat make-out-bad.sh
#!/bin/bash
outfile=out-bad.ps
rm -f $outfile
( cat save-sin.plt | gnuplot - ) > out-bad.ps;
kghostview $outfile;
#rm $outfile

hartman@ds0207:~/learning/gnuplot>cat make-out-good.sh
#!/bin/bash
outfile=out-good.ps
rm -f $outfile
( gnuplot save-sin.plt ) > $outfile;
kghostview $outfile;
#rm $outfile

hartman@ds0207:~/learning/gnuplot>cat save-sin.plt
# File name: save.plt - save a Gnuplot plot as a PostScript file
set terminal postscript portrait enhanced mono dashed lw 1 "Helvetica" 14
plot sin(x)

hartman@ds0207:~/learning/gnuplot>./compare-out-good-out-bad.sh
Terminal type set to 'postscript'
Options are 'portrait enhanced monochrome blacktext \
   dashed dashlength 1.0 linewidth 1.0 defaultplex \
   palfuncparam 2000,0.003 \
   butt "Helvetica" 14'

1c1
< gnuplot> gnuplot> gnuplot> %!PS-Adobe-2.0
---
> %!PS-Adobe-2.0
3c3
< %%CreationDate: Fri Mar 16 15:49:56 2007
---
> %%CreationDate: Fri Mar 16 15:49:54 2007
638c638
< gnuplot> %%Trailer
---
> %%Trailer

Re: gnuplot projects, terminal modules

[Petr M. <mi...@mo...>]

> Furthermore, it would be possible to do a more efficient job
> of "replot" in the core code that would benefit all terminals.
> Perhaps I am overlooking something, but I don't see any hard
> requirement to re-read the original data from a file on each
> replot command.  Yes, this is sometimes exactly what you want
> because you know the data has changed.  But more often you
> just want to redraw the plot with a different plot option,
> or zoom or view angle.  In these cases there should be enough,
> or almost enough, information already stored in the data structures
> from the previous plot.  Why re-read the data file when it is
> just storing the same information all over again?  This would in
> particular be of  plot '-', where it is very annoying to type in
> the same data all over again.  

Mousing in 3D -- rotating by mouse -- does not reread the data, but uses 
those in the memory. It would be useful for those "-" to do the same.

Thus there could be two replots, e.g. replot and Replot, where the second 
would not reread the data from disk.

---
PM