# Questions tagged [gnuplot]

Gnuplot is a portable command-line driven graphing utility for linux, OS/2, MS Windows, OSX, VMS, and many other platforms. Use this tag for questions about programmatic use of Gnuplot; debugging interactive usage is off-topic.

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### Heat Map using Chart::Gnuplot Perl

I was trying to create something like
But I was not able to get the x and y axis tics coming in
I tried something like this to see if the x axis tics are coming
my @data = (
[0, 0, 10],
...

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**1**answer

24 views

### Gnuplot fitting

I want to fit the following data:
70 0.0429065
100 0.041212
150 0.040117
200 0.035018
250 0.024366
300 0.02017
350 0.018255
400 0.015368
to the following function which is combination of an ...

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**1**answer

26 views

### gnuplot window in QtabWidget

I'm writing, as a learning project, a program in python3 with GUI in Qt5. My main window is a tabWidget and I would like to display in one of the tabs window with (interactive) plot generated in ...

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32 views

### Gnuplot, Windows: plot data from a logfile

I usual write my programs in plain vanilla C++. If I need graphical output, I use gnuplot or sometimes one of the portable bitmap formats. Now I have some kind of problem which I cannot solve by ...

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37 views

### gnuplot: how to get correct order of magnitude?

This question/issue is maybe related somehow to this topic.
If you type:
print log10(1e7) you will get 7.0.
print int(log10(1e7)) you will get 7.
However, if you type
print log10(1e6) you will ...

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33 views

### reverse tail for gnuplot

I would like to display data in a repeated online diagram with:
plot "tail -140 logging.dat | tac -r" with lines
I get an error message file cannot be opened, however in CLI it gives the reverse ...

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**1**answer

29 views

### gnuplot: compact axis label format

Tell me how in gnuplot to properly form the inscriptions in the axis (as shown in the picture).
1) I do not know the values of the y axis
2) I need to set the exponent (power 10) in the axis label ...

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**1**answer

17 views

### gnuplot, splot, 3d: cannot mix screen or character coords with plot coords

I have the following setup. There is a csv-file mini.csv, a gnuplot-script mwe.plt, and a shell-script mwe.sh to run it all.
The error I get is the following:
The contents of the above files are:
"...

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**1**answer

29 views

### Gnuplot contour plot without dots

I am trying to plot a contour plot with labels with the following code.
reset
set terminal qt
set pm3d map
set contour base
set cntrparam levels incremental 0, 10, 100
set cntrlabel onecolor
set ...

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15 views

### Does GnuPlot support 3D graphics formats for the export of 3D math graphics?

I would like to use GnuPlot for the creation of 3D parametric plots like the Klein Bottle. I want to use these surfaces as input for the Blender 3D editor and Renderer.
Until now I used Mathematica, ...

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22 views

### Gnuplot with qt terminal is slow to startup

Startup of gnuplot with qt terminal is slow. The warning message shown in the terminal (when trying to use the plot command) is
Warning: slow font initialization
The graph shown is also not correct. ...

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24 views

### Fitting Gaussian function to part of data

I have a set of data with multiple peaks of which I need only one fitted with a Gaussian function. I'm a bit inexperienced in Gnuplot so all my attempts ended in errors. Here's the code I've put ...

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28 views

### Gnuplot buttons greyed out

For years, I have used gnuplot from shell scripting and from the command line like this:
$ printf "1 2\n2 4\n3 6\n" > data.txt
$ echo "plot \"data.txt\" using 1:2" | gnuplot -persist
$
This gives ...

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24 views

### How do I correct Gnuplot libQt5XcbQpa.so.5 symbol lookup error?

Hi there I've installed some new packages recently and suddenly not sure why Gnuplot is refusing to plot things instead giving this error message:
/usr/lib/gnuplot/gnuplot_qt: symbol lookup error: /...

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**1**answer

28 views

### Uneven Grid Spacing of 3D splot in gnuplot

I have 3D data in a tab-delimited text file of form x,y,z. One dimension is equispaced, while the other has denser points near zero and they get sparse as you go further out. e.g.
178 200 .023......

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27 views

### gnuplot: display equation of line of fit for an exponential fit

I read from the second answer in this thread how to display the line of fit equation on a gnuplot for a linear line of fit. When I try to export that solution to my situation, which is an exponential ...

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**0**answers

42 views

### Inconsistency with gnuplot format specifiers %t and %T?

If you use the gnuplot format specifiers %t and %T, you will observe some inconsistent behaviour.
### gnuplot format specifiers
Numbers ="94 95 99 100 101"
do for [n in Numbers] {
print ...

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**1**answer

16 views

### Add an aditional space to xrange and yrange

I want to plot multiple files using a Gnuplot script.
However, I'm having some trouble to make it perfect.
My actual plots are something like that:
However, the linepoints plot is touching both the ...

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**1**answer

27 views

### space between concecutive rows in gnuplot pm3d map

There are no spaces between 1 and 3; 3 and 5. The 3rd row is not showing in the plot. Here is my Gnuplot :
set terminal jpeg size 1024,768
set output "test-gnu.jpg"
set pm3d map ...

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**1**answer

75 views

### How do visualize the rise or decline of occurrence of a word in a data set with timestamps [closed]

Im trying to make a graph like this
(actually single line for simplicity sake)
Given an input word like 'M4M" and a data set file (csv) like this
1529972216.0,Seeking Black M4M
1529972047.0,Looking ...

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**2**answers

25 views

### How to remove trailing zeros from gnuplot y tics in gnuplot?

I would like to apply a logarithmic scale on axis y with tics 10, 1, 0.1, 0.01, 0.001, 0.0001, and 0.00001 (without trailing zeros). Could you pleas help me how to provide this format to my GNUplot ...

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**1**answer

34 views

### Saving pdf output in gnuplot via qt

I was trying to save the output of a gnuplot plot as pdf using pdfcairo terminal by using the following code below:
reset
set terminal qt 1 noraise enhanced
set xlabel "Time (sec)"
set ylabel "...

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25 views

### gnuplot: thow to set the number of ticks on the axis

tell me how to specify the amount of numbers on the y-axis (the numbers themselves are unknown and depend on the data)
for example:
0 2 3 4 5 (tics count = 5)
or
150 300 450 (tics count = 3)

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**1**answer

32 views

### Gnuplot: Is it possible to skip header lines starting with a given character?

I have data files where header lines begin with the ampersand "&" character. Gnuplot does not like this (using the "plot" command with these files generates an error message). One way to handle ...

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**1**answer

14 views

### Defining different gnuplot environments

I have defined a few key bindings for gnuplot in a file key-bindings.gp which I can have available by launching gnuplot with
gnuplot key-bindings.gp -
However, if I do this, then gnuplot does not ...

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**1**answer

49 views

### gnuplot vector arrow length and streamlines

I have already asked about vector fields in here. Now I want to know a bit more about it.
How can I make it so that each arrow has the same fixed length and define the magnitude of the value by ...

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**1**answer

44 views

### gnuplot contour plot detail

So, I have a file with 3 columns (and 40000 rows), .First column is x coordinate, second is the y coordinate and 3rd column is "how many" and I want to produce a contour plot from this file. I ...

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**2**answers

32 views

### Gnuplot image to movie: Twinkling effect

I made png images using gnuplot:
do for [i=1:imax]{
imagefile='M'.sprintf("%5.5i",i).'.png'
datafile='A'.sprintf("%5.5i",j).'.dat'
plot datafile u 2:3:(rad*$6) with circles lc rgb "black" lw ...

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### gnuplot warning: could not confirm linked axis inverse mapping function

As a result of a simulation I have a gnuplot file that should generate a histogram using a datafile. When I run the gnuplot file I get these kind of warnings: could not confirm linked axis inverse ...

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**1**answer

79 views

### Draw set of points , lines in Gnuplot

I think this might be a really easy question for someone that has already used gnuplot and "splot" command, but I can't figure it right now as this is my first day using this program.
I achived ...

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28 views

### gnuplot: How to get datafile parameters into a variable?

Is there a way to get the gnuplot parameters "missing", "separator" and "commentschar" into a variable?
You can set these parametes, for example
set datafile missing "NaN"
set datafile separator ","
...

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**1**answer

20 views

### plot z value in each data point pm3d map

My question is about my code in gnuplot. I want to plot data with pm3d map and Matrix and want to plot the z value in each datapoint as well. I tried this:
set pm3d;set pm3d interpolate 0,0;set pm3d ...

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**1**answer

32 views

### Plot error_bars with lines in gnuplot

I have a file with the delivery rate of a simulation and its confidence interval. I need to plot an error bar on my chart. Need to be the line graph and also the error bar on a single chart
Delivery
...

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35 views

### vector field on gnuplot with u and v components

I'm solving Navier-Stokes equation for incompressible fluid flow through a square region with obstacle. As an output I get X and Y components of velocity as NxN matrix each. How to plot vector field ...

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27 views

### Gnuplot, how to plot data from a file .dat (No data in plot problem)

I am using Gnuplot on windows 10, I need to plot some file excel and to do that I copied and pasted evrything in a .dat file (ANSI), but everytime I try to do a simple plot (I mean the only "plot" ...

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22 views

### Errorbars in a Clustered Histogram

I am trying to get my output file to be a clustered histogram with error bars. However, I'm not sure how to do that, and the documentation hasn't helped too much (and neither have other stack exchange ...

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**1**answer

80 views

### System time and Gnuplot

I am constructing a normal X/Y data plot using column data from a .txt data file. The graph plots well (see general code below).
I am wondering if it is possible to extract and use a System time in ...

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**1**answer

50 views

### gnuplot grid remove grid from axes lines

gnuplot adds grid lines even on axes, it can cause unpleasant effects:
set logscale x
set xrange [0.01:100]
set xtics font ",12"
set x2tics font ",12"
set mxtics 10
set ytics font ",12"
set y2tics ...

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**1**answer

32 views

### 2D countour in gnuplot

How to make countour in gnuplot?
I want to plot:
5.300000e+04 1.300000e+02 5.436518e+06
5.300000e+04 1.325000e+02 5.126855e+06
5.300000e+04 1.350000e+02 4.803566e+06
5.300000e+04 1.375000e+02 4....

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52 views

### Gnuplot: categorised data - match color to data add range lines

Given a set of values fitting into a category, I'd like to
a) plot the data values as dots (y axis) according to category (x axis)
b) match dot color to category
c) add a line ranging from minimum to ...

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**2**answers

21 views

### gnuplot: labels to the axis - conver int (second) to hours

Tell me PLZ how I can make axis labels in the HOURS: MINUTES format (10:00 for example), if the data on the axis are represented as integers in the range [0...N]?
For example:
range [0..43200]
axis ...

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**1**answer

55 views

### gnuplot: use regular expressions to parse string

Tell me PLZ how in the gnuplot script you can
1) parse a string and extract a number and a letter/string from it?
2) is it possible to use associative arrays so as not to use multi IF?
files = ...

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**1**answer

35 views

### gnuplot x-axis extending past contour border

I am plotting a simple contour in gnuplot. The x-axis is being stubborn and keeps extending past the set range, leaving a weird gap between the end of the contour and the border. The data set extends ...

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17 views

### gnuplot: plot graphs with complex analysis of points coordinates

Tell me PLZ how to plot the graph so that I can manipulate the y coordinate?
For example:
before:
plot inputFullPath using 1:2 with lines ls 3 notitle
after:
function func(y)
{
return y * 3....

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22 views

### Visualize mesh in 2d plot / projection (gnuplot)

In my simulations, I have two numerical grids that overlap each other. One of them (the smaller one) is not rectangular but has a curved boundary (at least the area in which I care about it).
I would ...

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24 views

### Terminal set to “unknown” in gnuplot 5.2.6

I have installed gnuplot 5.2.6 package from 'http://gnuplot.sourceforge.net/' and installed in my ubuntu 18.04. After opening it in my terminal, I found terminal is set to unknown.
I tried to remove ...

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**1**answer

28 views

### Gnuplot, heat-map, label certain point

I am trying to plot a heat map and the plot is done. Though I need to label certain points with some name tags. I used the command label but it is not working. I checked but I didn't get any solution ...

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**1**answer

42 views

### Gnuplot - User - Error: “all points y value undefined!”

Here is my program. I am trying to plot data whose format looks fine to me. Gnuplot refuses to plot the data, saying that "y-values are undefined". What am I doing wrong?
set output "snowData.png"
...

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47 views

### How can I offset each data point individually depending on a variable?

I need to fit some function 'f(x)' to a set of data points 'y_i(x_i)' via gnuplot. Usually data points look like this:
y_1 x_1
y_2 x_2
y_3 x_3
...
but in my case there is a certain ambiguity:
(...

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26 views

### Default weighing criterion for gnuplot's 'lc palette'

I'm a novice in Gnuplot. Today I was plotting a simple txt file with two data columns, being the x and y coordinates of a cloud of points in the xy plane; I wanted to color them according to the ...