gnuplot-info — For questions and discussion about gnuplot

Re: [Gnuplot-info] confusing result

[BBands <bb...@gm...>]

Interger division: Try (1/4.0)*x**4.

     John

On Wed, Mar 4, 2015 at 8:49 AM, Wolfgang Schwanzer
<wol...@go...> wrote:
> Dear all!
>
>
>
> I'm a gnuplot novice and I'm really confused at the moment.
>
> Why is 0.25*x**4 not the same as (1/4)*x**4?

Re: [Gnuplot-info] confusing result

[Dave H. <da...@ho...>]

On Wed, 4 Mar 2015, Wolfgang Schwanzer wrote:

> Why is 0.25*x**4 not the same as (1/4)*x**4?

Because (1/4) evaluates to zero?

-- 
Dave Horsfall DTM (VK2KFU)  "Bliss is a MacBook with a FreeBSD server."
http://www.horsfall.org/spam.html (and check the home page whilst you're there)

[Gnuplot-info] confusing result

[Wolfgang S. <wol...@go...>]

Dear all!

 

I'm a gnuplot novice and I'm really confused at the moment.

Why is 0.25*x**4 not the same as (1/4)*x**4?

 

Please help.

 

Thanks

Wolfgang

 

[Gnuplot-info] Plot waltzes across screen with "Save As..."

[Dave H. <da...@ho...>]

Gnuplot 4.6.6 on Yosemite 10.10.2

Not sure if this is a Gnuplot/Aqua/Mac issue, so...

Plotting a graph (to an Aqua window) and using "Save As...", the window 
itself waltzes across the screen, diagonally, by about half a cm, each 
time.  When it hits the opposite corner it resets :-)

Even quitting and restarting it remembers where it left off (I've just 
tried it), so perhaps it isn't a Gnuplot issue after all?

Anyone else see this?  It's mildly annoying.

-- 
Dave Horsfall DTM (VK2KFU)  "Bliss is a MacBook with a FreeBSD server."
http://www.horsfall.org/spam.html (and check the home page whilst you're there)

Re: [Gnuplot-info] How to change default properties?

[theozh <th...@gm...>]

sorry, again...
not "lc" but "tc" was missing...

set label 1 "Text1" tc lt 1
...

is correct.

Re: [Gnuplot-info] How to change default properties?

[theozh <th...@gm...>]

just for completeness...
correction:
for labels "lc" was missing

set label 1 "Text1" lc lt 1
...

Re: [Gnuplot-info] How to change default properties?

[theozh <th...@gm...>]

aah... so easy...
ok, spending an "lt 1" for each label
and defining lt 1 beforehand and in case of change just redefining that
single line.

set linetype lc rgb "rgb"  # or whatever
set label 1 "Text1" lt 1
set label 2 "Text2" lt 1
...
set label n "TextN" lt 1

Thanks!

> 'set linetype' is your friend.
> 
> Details at 'help set linetype'
> 
>     John
> 

Re: [Gnuplot-info] How to change default properties?

[BBands <bb...@gm...>]

'set linetype' is your friend.

Details at 'help set linetype'

    John

On Thu, Feb 12, 2015 at 1:10 AM, theozh <th...@gm...> wrote:
> a simple question...
>
> I haven't yet found a way to change e.g. the default textcolor (or other
> properties) of labels (or other objects).

[Gnuplot-info] How to change default properties?

[theozh <th...@gm...>]

a simple question...

I haven't yet found a way to change e.g. the default textcolor (or other
properties) of labels (or other objects).

For example, the standard textcolor is black, so if you type:

set label 1 "Text1" tc rgb "red"
set label 2 "Text2"
...
set label n "TextN"

Text2 to "TextN" will be in black. OK, fine, it seems if you want n
labels in red you have to specify each time the color for each label.
I was hoping that there is something like:

set textcolor rgb "red"   # from now on all labels are in red
or
set style label tc rgb "red"

set label 1 "Text1"
set label 2 "Text2"
...
set label n "TextN"

Which would make it easier to change the color at once of all following
labels or objects by simply change a single line of code.
Is there another simple way to do that?

Re: [Gnuplot-info] using hypertext labels with multiple datasets and a key/legend

[Kevin K. <kk...@gm...>]

Thanks for the tips.  I was able to get a plot with both data points and
hypertext labels on the plot but with only data points visible in the
legend using a command of this form:

plot <filename> using 1:2 title <title> w points, <filename> using 1:2:3
notitle w labels hypertext point lc rgb #FFFFFFFF

note that I made the points associated with the hypertext labels
transparent.  I did this because I did not want to see visible points on
the graph associated with the hypertext labels (that's what the first plot
statement is for - to create the actual visible data points on the graph),
yet the hypertext labels apparently don't work unless there is an actual
point on the graph associated with the label via the "point" statement that
follows "w labels hypertext".  I tried setting the hypertext point size to
0 and also tried using nopoint, but these prevented the labels from showing
up.

Kevin

On Sun, Feb 8, 2015 at 6:56 PM, Ethan A Merritt <EAM...@gm...> wrote:

> On Tuesday, 03 February 2015 05:37:50 PM Kevin Klein wrote:
> > I am trying to use Gnuplot 5's hypertext labels in conjunction with
> > multiple datasets on the same plot and am finding that when I add the
> > hypertext labels it removes the identifying color markings in my key.
> >
> > The following works fine and produces a plot with a legend/key in the
> upper
> > right with a blue box next to v5 and a green box next to v6:
> >
> > set term svg size 600,400 dynamic mousing name "test"
> > set output "test.svg"
> > plot "data_file.txt" using 1:2 title 'v5' w point pt 5 lc rgb 'blue',
> > "data_file.txt" using 4:5 title 'v6' w point pt 5 lc rgb 'green'
> >
> > Now I want to recreate the same plot with some hypertext labels:
> >
> > set term svg size 600,400 dynamic mousing name "test"
> > set output "test.svg"
> > plot "data_file.txt" using 1:2:3 title 'v5' w labels hypertext point pt 5
> > lc rgb 'blue', "data_file.txt" using 4:5:6 title 'v6' w labels hypertext
> > point pt 5 lc rgb 'green'
> >
> > The plot is created and the hypertext labels appear when I mouse over the
> > data points, but my legend/key in the upper right no longer contains a
> blue
> > and green box next to the dataset titles.  It is just blank white where
> the
> > two separate color points should be.  Why is this happening?
>
>
> Each plot style places a corresponding symbol in the key together with
> its title.  "with lines" places a line, "with boxes" places a box,
> "with points" places a point, and so on.  "with labels" does not place
> a separate symbol because its primary feauture text and the corresponding
> title already representes text.
>
> So your plot "with points" showed a point in the key.
> Your plot "with labels" did not.  Hypertext is actually not relevant here.
>
> Having said that, I am sympathetic to the idea that a plot using
> "with labels point pointtype 7 lc 'green'" could place a filled green
> circle next to the plot title just as it does next to each label in
> the plot itself.  I suggest you add that as a Feature Request on the
> issues tracker on the project's SourceForge page.
>
> Meanwhile you could use the approach in the hypertext demo
>    http://gnuplot.sourceforge.net/demo_svg_5.0/hypertext.html
> The data is plotted twice, once "with points" and then again
> "with labels hypertext".  The demo doesn't use a key, but if you
> enable the key then the "with points" plot will be represented
> by a corresponding point sample in the key.
>
>         Ethan
>
>
>
> >
> >
> > Here are the contents of data_file.txt:
> >
> > 150            1                 x1   185            1                 x1
> > 105            1                 x2   140            1                 x2
> > 140            1                 x3   180            1                 x3
>
>

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Elias A. <eli...@gm...>]

On 02/09/2015 09:15 PM, Ethan Merritt wrote:
> Ah, sorry, so what I really misunderstood was your statement "I do see
> the difference with and without antialiasing".  I thought you meant
> you saw the same asymmetry with and without antialiasing.

Now that I read it again I have to agree that sentence was not very well 
written.

> But I am mystified about the asymmetry in the x11 screenshot.  I can't
> reproduce that.

I only see it on one of the two machines I tried, although the setup is 
more or less the same (same configure options, “same” OS).  If there is 
anything you want me to try on that machine, just ask.

On the other hand, for me this problem is actually not severe.  It does 
not affect my ability to read the plots, and for production quality 
plots I will use the pdf or png terminals anyway.


	Elias

[Gnuplot-info] Interpolated topographic map from matrix data

[theozh <th...@gm...>]

Dear gnuplot experts,

if I have for example a 10x10 matrix like:

0.005 0.383 0.666 0.947 1.258 1.618 1.959 2.185 2.250 2.180
0.153 0.860 1.875 2.945 3.915 4.680 5.048 4.982 4.614 4.139
0.217 1.251 2.932 4.764 6.179 6.880 6.819 6.250 5.533 4.879
0.271 1.619 3.837 6.069 7.347 7.533 6.963 6.145 5.396 4.827
0.320 1.897 4.345 6.407 7.147 6.848 6.117 5.385 4.830 4.459
0.346 1.962 4.201 5.708 5.961 5.523 4.932 4.447 4.134 3.985
0.326 1.756 3.502 4.473 4.521 4.186 3.821 3.570 3.467 3.484
0.273 1.371 2.582 3.184 3.212 3.041 2.873 2.800 2.833 2.952
0.201 0.964 1.750 2.149 2.205 2.153 2.114 2.151 2.263 2.448
0.134 0.633 1.141 1.423 1.504 1.517 1.556 1.644 1.792 1.997


I thought it should be possible to draw a "topological" map with contour
lines.

Searching the web I found this description:
http://stackoverflow.com/questions/20977368/filled-contour-plot-with-constant-color-between-contour-lines

My gnuplot code:
reset
set contour base
set cntrparam level 10
unset surface
set table "Matrix3c.dat"
splot "Matrix3.dat" matrix w l
unset table
set palette maxcolors 10
plot "Matrix3.dat" matrix with image, "Matrix3c.dat" w l lc rgb "black"

Since in my case it is not a continous function but a matrix of 10x10
datapoints I still get a pattern of 10x10 color squares instead of
uniform color areas between the contour lines.
Do I have to interpolate and blow up the 10x10 matrix e.g. to a 100x100
matrix or are there better ways which I do not see?

Thanks for any hints, Theo.

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Ethan M. <eam...@gm...>]

Ah, sorry, so what I really misunderstood was your statement "I do see
the difference with and without antialiasing".  I thought you meant
you saw the same asymmetry with and without antialiasing.

So I take it we now agree that the problem is with qt's antialiasing.

But I am mystified about the asymmetry in the x11 screenshot.  I can't
reproduce that.


On Mon, Feb 9, 2015 at 10:51 AM, Elias Assmann <eli...@gm...> wrote:
> On 02/09/2015 06:34 PM, Ethan A Merritt wrote:
>>
>> On Monday, 09 February 2015 01:24:00 PM Elias Assmann wrote:
>>>
>>> I now managed to compile gnuplot 5 against Qt5 on my laptop (the second
>>> machine I referred to), and I do see the difference with and without
>>> antialiasing.
>>
>>
>> Maybe I'm still not understanding fully what you mean by asymmetric.
>> Here is an enlargement of your attached screenshot qt_no-antialias.png.
>> To my eye the '+' and '*' symbols for point types 1 and 2 look
>> perfectly symmetric.
>
>
> Please look at ‘qt_antialias.png’ instead.  You will see that the ‘+’s are
> symmetric, but the ‘x’s are not (in the +, x, and * markers).
>
>
>         Elias
>

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Elias A. <eli...@gm...>]

On 02/09/2015 06:34 PM, Ethan A Merritt wrote:
> On Monday, 09 February 2015 01:24:00 PM Elias Assmann wrote:
>> I now managed to compile gnuplot 5 against Qt5 on my laptop (the second
>> machine I referred to), and I do see the difference with and without
>> antialiasing.
>
> Maybe I'm still not understanding fully what you mean by asymmetric.
> Here is an enlargement of your attached screenshot qt_no-antialias.png.
> To my eye the '+' and '*' symbols for point types 1 and 2 look
> perfectly symmetric.

Please look at ‘qt_antialias.png’ instead.  You will see that the ‘+’s 
are symmetric, but the ‘x’s are not (in the +, x, and * markers).


	Elias

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[BBands <bb...@gm...>]

+1 for Post of the Month

On Mon, Feb 9, 2015 at 3:50 AM, Elias Assmann <eli...@gm...> wrote:

> PS: You see, such is my faith in gnuplot that when I encounter a bug, I
> assume it is a new feature that I am not quite getting.

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Elias A. <eli...@gm...>]

Hi Ethan,

Thank you for the research.  I can confirm Leo's report — what I see 
looks just like what he posted, including the symmetric points in the 
grayscaled PDFs.

Saved SVGs also show symmetric markers, while a saved PNG has the 
asymmetric ones (although the asymmetry is left-right reversed with 
respect to the terminal!).  However, I do not see any change when I turn 
off antialiasing in the dialog.

(Note: I am writing from a different machine than before — here, I have 
not managed to compile the gnuplot 5 qt terminal, but the results with 
gnuplot4.6/qt look identical, as far as I can tell.)

Should I still submit a bug report?  (About the missing color?)


	Elias


PS: You see, such is my faith in gnuplot that when I encounter a bug, I 
assume it is a new feature that I am not quite getting.

Re: [Gnuplot-info] using hypertext labels with multiple datasets and a key/legend

[Ethan A M. <EAM...@gm...>]

On Tuesday, 03 February 2015 05:37:50 PM Kevin Klein wrote:
> I am trying to use Gnuplot 5's hypertext labels in conjunction with
> multiple datasets on the same plot and am finding that when I add the
> hypertext labels it removes the identifying color markings in my key.
> 
> The following works fine and produces a plot with a legend/key in the upper
> right with a blue box next to v5 and a green box next to v6:
> 
> set term svg size 600,400 dynamic mousing name "test"
> set output "test.svg"
> plot "data_file.txt" using 1:2 title 'v5' w point pt 5 lc rgb 'blue',
> "data_file.txt" using 4:5 title 'v6' w point pt 5 lc rgb 'green'
> 
> Now I want to recreate the same plot with some hypertext labels:
> 
> set term svg size 600,400 dynamic mousing name "test"
> set output "test.svg"
> plot "data_file.txt" using 1:2:3 title 'v5' w labels hypertext point pt 5
> lc rgb 'blue', "data_file.txt" using 4:5:6 title 'v6' w labels hypertext
> point pt 5 lc rgb 'green'
> 
> The plot is created and the hypertext labels appear when I mouse over the
> data points, but my legend/key in the upper right no longer contains a blue
> and green box next to the dataset titles.  It is just blank white where the
> two separate color points should be.  Why is this happening?


Each plot style places a corresponding symbol in the key together with 
its title.  "with lines" places a line, "with boxes" places a box,
"with points" places a point, and so on.  "with labels" does not place
a separate symbol because its primary feauture text and the corresponding
title already representes text.

So your plot "with points" showed a point in the key.
Your plot "with labels" did not.  Hypertext is actually not relevant here.

Having said that, I am sympathetic to the idea that a plot using
"with labels point pointtype 7 lc 'green'" could place a filled green
circle next to the plot title just as it does next to each label in
the plot itself.  I suggest you add that as a Feature Request on the
issues tracker on the project's SourceForge page. 

Meanwhile you could use the approach in the hypertext demo
   http://gnuplot.sourceforge.net/demo_svg_5.0/hypertext.html
The data is plotted twice, once "with points" and then again
"with labels hypertext".  The demo doesn't use a key, but if you 
enable the key then the "with points" plot will be represented
by a corresponding point sample in the key.

	Ethan



> 
> 
> Here are the contents of data_file.txt:
> 
> 150            1                 x1   185            1                 x1
> 105            1                 x2   140            1                 x2
> 140            1                 x3   180            1                 x3

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Ethan M. <eam...@gm...>]

On Thu, Feb 5, 2015 at 3:54 AM, Elias Assmann <eli...@gm...> wrote:
> On 02/04/2015 06:41 PM, - wrote:
>> Can I ask what are the advantages of Qt over wxt?
>
> The release notes say “[Qt] is now the fastest and most full-featured
> interactive terminal option”.  Beyond that, this is just what I wanted
> to see for myself.
>
> One of the most first differences I noticed is that the symbols (when
> plotting ‘with points’ or ‘with linespoints’) are asymmetric.  What is
> the purpose of that?

Could you clarify what you mean by "asymmetric"?
I attach a pdf file of a test of the qt terminal from version 5.
This shows
1) the points are symmetric (at least to my eye)
2) export to pdf does produce a color plot

If your setup is producing something else, please file a bug report on the
tracker with information about the system, particularly the qt version.

     Ethan




> At first I thought it was so that you could tell apart different symbols
> more easily when points are on top of each other (e.g., like a “*” will
> hide “+” and “x” below it).  But that is not the case since all of the
> symbols are asymmetric in the same way.

Re: [Gnuplot-info] Grayscale PDF from Qt

[BBands <bb...@gm...>]

I just built 5.0.0 against qt4--I couldn't figure out how to get it to
build against qt5--on linux and can confirm this behavior. The png and
svg saves are in full color, but the pdf is gray scaled.

      John

On Thu, Feb 5, 2015 at 6:22 AM, Elias Assmann <eli...@gm...> wrote:
> Hi,
>
> I love the new feature that lets me save a PDF directly from the wxt /
> qt terminal.  However, from Qt I get grayscale PDFs (SVG/PNG from Qt and
> all formats from wxt are in color).
>
> In this thread
> <http://gnuplot.10905.n7.nabble.com/Proposal-Saving-graphs-from-Qt-and-wxt-terminals-td18874.html>,
> somebody had the same problem but then: “The color is working for me
> now.  I'm not sure what happened.”  Whatever it was, it has not happened
> for me yet.
>
> Does anybody know what needs to happen to get the color PDFs?
>
> Granted, it is not a big issue in practice, I could just revert to wxt …

Re: [Gnuplot-info] Grayscale PDF from Qt

[Mathias M. <mu...@ph...>]

Hi,

maybe you can give us some more information on how you plot and save.
Do you change the term settings?

I am running Gnuplot with Version 4.6 patchlevel 6 (last modified September 2014) [Archlinux package: gnuplot 4.6.6.1].
The default settings after freshly starting gnuplot result in colored pdf files, when saving right from the gaphic dialog.

Cheers,

/M

On  0, Elias Assmann <eli...@gm...> wrote:
> Hi,
> 
> I love the new feature that lets me save a PDF directly from the wxt / 
> qt terminal.  However, from Qt I get grayscale PDFs (SVG/PNG from Qt and 
> all formats from wxt are in color).
> 
> In this thread 
> <http://gnuplot.10905.n7.nabble.com/Proposal-Saving-graphs-from-Qt-and-wxt-terminals-td18874.html>, 
> somebody had the same problem but then: “The color is working for me 
> now.  I'm not sure what happened.”  Whatever it was, it has not happened 
> for me yet.
> 
> Does anybody know what needs to happen to get the color PDFs?
> 
> Granted, it is not a big issue in practice, I could just revert to wxt …
> 
> 
> 	Elias

Re: [Gnuplot-info] Grayscale PDF from Qt

[Elias A. <eli...@gm...>]

On 02/05/2015 03:59 PM, Mathias Müller wrote:
> maybe you can give us some more information on how you plot and save.
> Do you change the term settings?

I do not.  I am using gnuplot 5.0.0 compiled against Qt5 (sorry I did 
not mention this originally).  Just starting gnuplot and, e.g.,

 > gnuplot-5.0

	G N U P L O T
	Version 5.0 patchlevel 0    last modified 2015-01-01

	Copyright (C) 1986-1993, 1998, 2004, 2007-2015
	Thomas Williams, Colin Kelley and many others

	gnuplot home:     http://www.gnuplot.info
	faq, bugs, etc:   type "help FAQ"
	immediate help:   type "help"  (plot window: hit 'h')

Terminal type set to 'qt'
gnuplot> p sin(x)

and clicking “Export to PDF” results in a grayscale PDF.


	Elias

[Gnuplot-info] Grayscale PDF from Qt

[Elias A. <eli...@gm...>]

Hi,

I love the new feature that lets me save a PDF directly from the wxt / 
qt terminal.  However, from Qt I get grayscale PDFs (SVG/PNG from Qt and 
all formats from wxt are in color).

In this thread 
<http://gnuplot.10905.n7.nabble.com/Proposal-Saving-graphs-from-Qt-and-wxt-terminals-td18874.html>, 
somebody had the same problem but then: “The color is working for me 
now.  I'm not sure what happened.”  Whatever it was, it has not happened 
for me yet.

Does anybody know what needs to happen to get the color PDFs?

Granted, it is not a big issue in practice, I could just revert to wxt …


	Elias

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Elias A. <eli...@gm...>]

On 02/04/2015 06:41 PM, - wrote:
> Can I ask what are the advantages of Qt over wxt?

The release notes say “[Qt] is now the fastest and most full-featured 
interactive terminal option”.  Beyond that, this is just what I wanted 
to see for myself.

One of the most first differences I noticed is that the symbols (when 
plotting ‘with points’ or ‘with linespoints’) are asymmetric.  What is 
the purpose of that?

At first I thought it was so that you could tell apart different symbols 
more easily when points are on top of each other (e.g., like a “*” will 
hide “+” and “x” below it).  But that is not the case since all of the 
symbols are asymmetric in the same way.


	Elias

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[Elias A. <eli...@gm...>]

On 02/04/2015 06:13 PM, Ethan A Merritt wrote:
> Is there in fact a gnuplot_qt executable in /usr/local/libexec/gnuplot/5.0/ ?

There was not, and it turns out that is the solution.  I had used 
--program-suffix=-5.0 in ‘configure’, so there was

-rwxr-xr-x 1 root root 2797689 Feb  4 10:42 gnuplot_qt-5.0*
-rwxr-xr-x 1 root root  330062 Feb  4 10:42 gnuplot_x11-5.0*

but no ‘gnuplot_qt’.  Upon creating an appropriate symlink, the ‘qt’ 
terminal works!

By the way, the ‘x11’ terminal works even though there is no 
‘gnuplot_x11’ executable.

Thank you.

	Elias

Re: [Gnuplot-info] qt terminal hangs in gnuplot 5.0

[- <mle...@gm...>]

Can I ask what are the advantages of Qt over wxt?

Leo

On Wed, Feb 4, 2015 at 5:13 PM, Ethan A Merritt <EAM...@gm...> wrote:

> On Wednesday, 04 February 2015 11:11:19 AM Elias Assmann wrote:
> > Hi List,
> >
> > I have successfully compiled gnuplot 5.0.0, and the ‘wxt’ and ‘x11’
> > terminals work fine.  But when I try to plot something with the ‘qt’
> > terminal, gnuplot complains
> >
> >     gnuplot> p [-4:4] sin(x), [0:pi] cos(x)
> >     Could not start gnuplot_qt with path
> > "/usr/local/libexec/gnuplot/5.0/gnuplot_qt"
> >     Could not start gnuplot_qt with path
> > "/usr/local/libexec/gnuplot/5.0/gnuplot_qt"
> >     Could not connect to gnuplot_qt "" . Starting a new one
> >     Could not start gnuplot_qt with path
> > "/usr/local/libexec/gnuplot/5.0/gnuplot_qt"
> >
> >     Warning: slow font initializationgnuplot>
> >
> > This looks like the error that was reported on Cygwin
> > <http://sourceforge.net/p/gnuplot/mailman/message/33209231/>, but I am
> > on an Ubuntu system.  I see the same behavior whether I compile with
> > Qt4 or Qt5.
> >
> > Any pointers?
>
> Is there in fact a gnuplot_qt executable in
> /usr/local/libexec/gnuplot/5.0/ ?
>
>
> --
>
>
>
> ------------------------------------------------------------------------------
> Dive into the World of Parallel Programming. The Go Parallel Website,
> sponsored by Intel and developed in partnership with Slashdot Media, is
> your
> hub for all things parallel software development, from weekly thought
> leadership blogs to news, videos, case studies, tutorials and more. Take a
> look and join the conversation now. http://goparallel.sourceforge.net/
> _______________________________________________
> gnuplot-info mailing list
> gnu...@li...
> Membership management via:
> https://lists.sourceforge.net/lists/listinfo/gnuplot-info
>