Thicker lines in the legend of gnuplot - gnuplot

I'm plotting some data curves with gnuplot, and they look like this:
However, the line samples in the legend are too thin. When you have more curves, it becomes hard to distinguish the colors. You can increase the thickness of the curves using "linewidth", e.g., by adding "lw 3" to the plot command, and you'd get this:
However, this increases the thickness everywhere. Is it possible to make the lines thick in the legend only? I know it can be done "the other way", by postprocessing on the output .png file. But is there a direct approach, using some gnuplot setting/wizardry?

Unfortunately, I don't know a way to control the thickness of the lines in the key, since they correspond to the lines being drawn. You can see what you can change by typing help set key in gnuplot.
Using multiplot, you can draw the plot lines first without the key, then draw the key again for 'ghost lines'. Here is a code sample which would do that:
set terminal png color size 800,600
set output 'plot.png'
set multiplot
unset key
plot '../batteries/9v/carrefour.txt' w lp, \
'../batteries/9v/philips.txt' w lp, \
'../batteries/9v/sony.txt' w lp
set key; unset tics; unset border; unset xlabel; unset ylabel
plot [][0:1] 2 title 'Carrefour' lw 4, \
2 title 'Philips' lw 4, \
2 title 'Sony' lw 4
In the second plot command, the function 2 (a constant) is being plotted with a y range of 0 to 1, so it doesn't show up.

I ran across this post and it gave me a critical idea.
The provided solution does not work in multiplot mode, since the second plot command will trigger the second plot, which is most likely not desired.
as a workaround one can set the original data as "notitle", then plot data outside of range with the same linetype and color in different thickness with the desired title. I'll just leave my current example here. It also includes linestyles that i have declared. So i just use the same linestyle (ls) to get the same color but change the thickness on the second line.
# for pngs
set terminal pngcairo size 1600,600 font ',18' enhanced
set output "pic_multi_kenngr_ana.png
set style line 2 lc rgb '#0ce90b' lt 1 lw 1.5 # --- green
set style line 3 lc rgb '#09e0b3' lt 1 lw 1.5 # .
set style line 4 lc rgb '#065fd8' lt 1 lw 1.5 # .
set style line 5 lc rgb '#4e04cf' lt 1 lw 1.5 # .
set style line 6 lc rgb '#c702a9' lt 1 lw 1.5 # .
set style line 7 lc rgb '#bf000a' lt 1 lw 1.5 # --- red
set multiplot layout 1,2
set xtics rotate
set tmargin 5
set xtics 12
set grid xtics
# set axis labels
set ylabel 'T [K]'
set xlabel 'Zeit [h]'
# select range
set xrange [0:48]
set yrange [290.15:306.15]
set title "(a) Bodentemperatur"
set key top right Right
plot 'par_crank_hom01lvls.04.dat' u 1:3 with lines ls 7 notitle,\
'par_crank_str01lvls.16.dat' u 1:3 with lines ls 2 notitle,\
500 t 'z = 4 cm' ls 7 lw 4,\
500 t 'z = 16 cm' ls 2 lw 4
################################################
set title "(b) Bodenwärmestrom an der Oberfläche"
set ylabel 'G [W m^{-2}]'
set yrange[-110:110]
unset key
plot 'par_crank_str01_ghf.dat' u 1:3 with lines
unset multiplot
I hope this will help someone

An even more simple work-around (imho) is to define the colours explicitly and plot each line twice, once with high lw for the key and also with the title to appear in the key, but adding "every ::0::0" which effectively ends up in plotting nothing, and once the normal way. See the following code snippet:
plot data u 0:1 w l linecolor rgb #1b9e77 lw 2 t "",\
data every ::0::0 u 0:1 w l linecolor rgb #1b9e77 lw 4 t "Title"

To expand on the NaN comment by #Svalorzen, the following will graph two lines of width 1 from some datafile.txt with no titles and create matching blank lines with the specified titles and width 5 for the key only:
plot [][]\
NaN title "Title1" w line lt 1 lc 1 lw 5,\
NaN title "Title2" w line lt 1 lc 2 lw 5,\
"datafile.txt" using 1:2 title "" w line lt 1 lc 1 lw 1,\
"datafile.txt" using 1:3 title "" w line lt 1 lc 2 lw 1

I find an answer for this:
Set key linewidth
in your case, must be:
plot '../batteries/9v/carrefour.txt' w l lw 1 linetype 1 notitle, 0/0 linetype 1 linewidth 5 title 'Carrefour'
rep '../batteries/9v/philips.txt' w l lw 1 linetype 2 notitle, 0/0 linetype 2 linewidth 5 title 'Philips'
rep '../batteries/9v/sony.txt' w l lw 1, linetype 3 notitle, 0/0 linetype 3 linewidth 5 title 'Sony'

Try something like:
plot # ... \
keyentry w l lw 1 lc 2 t "Title" # ...
And remove the old keys.

Related

Separate key (legend) for colors and markers

I have a plot with several types of objects (each read from a separate file). I'm plotting the same several functions for all of them, all on the same graph (same X-axis).
I set the markers (pt) explicitly for each, and the color (lc), so the same object has the same marker, but the same function has the same color. As an example we have 2 files, one for each object (| is just to separate the files here):
0 0 0 | 0 1 1
1 1 2 | 1 1 2
Let's call the left file A, the right B. Column 1 in each file is the x axis, column 2 is using 1:2, and column 3 is using 1:3. So using the above files in an interactive session:
gnuplot> plot "A" using 1:2 with lp pt 1 lc 'black'
gnuplot> replot "A" using 1:3 with lp pt 1 lc 'red'
gnuplot> replot "B" using 1:2 with lp pt 2 lc 'black'
gnuplot> replot "B" using 1:3 with lp pt 2 lc 'red'
we get:
Is it possible to have the key separated, so A/B appear next to their respective marker, and the function name ("using...") appears next to a line (or anything) with the appropriate color?
Right now by omitting titles (notitle in the plot command) I can get one or the other, though I would have to settle on some uniform arbitrary marker/color (depending on what I chose to set as key). Can I:
Get two keys somehow? - Preferably setting the missing attribute (color or marker) to something not in the plot.
If not, can I customize a manual legend somehow?
I am not fully sure what you want to achieve, nevertheless as for the splitting of the key, I don't think that Gnuplot has some "out-of-the-box" feature for this. However, you could (ab)use multiplot to achieve this effect. The idea is basically to generate two overlapping plots - one with points and one with lines - and to position the keys independently:
set terminal pngcairo rounded font ",16"
set output 'fig.png'
$A << EOD
0 0 0
1 1 2
EOD
$B << EOD
0 1 1
1 1 2
EOD
set multiplot
set xtics out nomirror
set ytics out nomirror
eps = 0.1
set lmargin at screen eps
set rmargin at screen 1 - eps/2
set bmargin at screen eps
set tmargin at screen 1 - eps/2
#common key settings
set key left top Left reverse spacing 1.5
set key at screen 0.1,screen 1-eps
plot \
$A u 1:2 with p ps 1.5 pt 1 lc 'black' t 'A', \
$A u 1:3 with p ps 1.5 pt 1 lc 'red' t 'A' , \
$B u 1:2 with p ps 1.5 pt 2 lc 'black' t 'B', \
$B u 1:3 with p ps 1.5 pt 2 lc 'red' t 'B'
unset border; unset xtics; unset ytics
set key at screen 0.3,screen 1-eps
plot \
$A u 1:2 with l lc 'black' t 'using 1:2', \
$A u 1:3 with l lc 'red' t 'using 1:3', \
$B u 1:2 with l lc 'black' t '', \
$B u 1:3 with l lc 'red' t ''
This would give you:

GNUPLOT: First data row not shown in barchar [duplicate]

Am using gnuplot 5.0. with the following as pereamble to each script:
set terminal epslatex 8 color standalone colortext
The issue is that gnuplot is skipping the first row. To my knowledge 4.6 version addressed a similar issue.
Any idea on the problem please?
Example of data file points.dat
4 4
4 -4
-4 4
-4 -4
The first line (4, 4) is skipped. So instead of four points, only three are displayed by gnuplot. Herewith the command am using
#!/bin/bash
set terminal epslatex 8 color standalone colortext
set output outputFileName
set size .55,.55
set pointsize 3.0
##############
# Line styles
##############
set linestyle 1 lt 5 lw 1 #
set linestyle 2 lt 2 lw 1.5
set linestyle 3 lt 6 lw 1 #
set linestyle 4 lt 3 lw 1
set linestyle 5 lt 2 lw 2 #
set linestyle 6 lt 1 lw 2
##################
# Titles
##################
set title 'Image'
set xlabel '$x$' offset 0,0.5
set ylabel '$y$' offset 2,0
set macros
filename_init = sprintf("%s/image_init.dat",dataFileDirectory)
set key autotitle columnhead
set key horiz
set multiplot
plot
filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta" notitle 'initial'
On trick to bypass the issue is to duplicate the first row. Bu this is not practical.
With set key autotitle columnheader gnuplot uses the entries in the first row as key entries, even though for the plot you have specified notitle.
To demonstrate this, consider the following script, using the four data points in points.dat, which you posted:
set terminal pngcairo
set output 'foobar.png'
set offsets 1,1,1,1
set key autotitle columnhead
filename_init = 'points.dat'
set multiplot layout 1,2
plot filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta"
set key noautotitle
plot filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta" title 'initial'
unset multiplot
The result is
So, just remove the line set key autotitle columnhead from your script, and use plot ... title 'initial'. That gives you the expected result.

gnuplot: first row of data skipped

Am using gnuplot 5.0. with the following as pereamble to each script:
set terminal epslatex 8 color standalone colortext
The issue is that gnuplot is skipping the first row. To my knowledge 4.6 version addressed a similar issue.
Any idea on the problem please?
Example of data file points.dat
4 4
4 -4
-4 4
-4 -4
The first line (4, 4) is skipped. So instead of four points, only three are displayed by gnuplot. Herewith the command am using
#!/bin/bash
set terminal epslatex 8 color standalone colortext
set output outputFileName
set size .55,.55
set pointsize 3.0
##############
# Line styles
##############
set linestyle 1 lt 5 lw 1 #
set linestyle 2 lt 2 lw 1.5
set linestyle 3 lt 6 lw 1 #
set linestyle 4 lt 3 lw 1
set linestyle 5 lt 2 lw 2 #
set linestyle 6 lt 1 lw 2
##################
# Titles
##################
set title 'Image'
set xlabel '$x$' offset 0,0.5
set ylabel '$y$' offset 2,0
set macros
filename_init = sprintf("%s/image_init.dat",dataFileDirectory)
set key autotitle columnhead
set key horiz
set multiplot
plot
filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta" notitle 'initial'
On trick to bypass the issue is to duplicate the first row. Bu this is not practical.
With set key autotitle columnheader gnuplot uses the entries in the first row as key entries, even though for the plot you have specified notitle.
To demonstrate this, consider the following script, using the four data points in points.dat, which you posted:
set terminal pngcairo
set output 'foobar.png'
set offsets 1,1,1,1
set key autotitle columnhead
filename_init = 'points.dat'
set multiplot layout 1,2
plot filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta"
set key noautotitle
plot filename_init u 1:2 with points lt 0 pt 1 lw 5 lc rgb "magenta" title 'initial'
unset multiplot
The result is
So, just remove the line set key autotitle columnhead from your script, and use plot ... title 'initial'. That gives you the expected result.

Same Gnuplot linestyle as in graph in key/legend

I would like to plot a legend/key, which shows the different symbols on the line. Currently my plots look like this:
Unfortunately the symbols (triangle, rectangle and circle) are not shown in the key/legend. How is it possible to add them?
I use the following gnuplot script:
set title tit font "palatino,20"
set xlabel xlbl font "palatino,20"
set ylabel ylbl font "palatino,20"
#set logscale x
set output graphfilename.".pdf"
set terminal pdf
set border linewidth 2
set style line 1 lc rgb '#0060ad' lt 1 lw 2 pt 5 # --- blue
set style line 2 lc rgb '#00ad60' lt 1 lw 2 pt 7 # red .
set style line 3 lc rgb '#ad0000' lt 1 lw 2 pt 9 # green .
set tics scale 0.8
set key below
plot file1 using ($1/1000):($2/1000000):($3/1000000):($4/1000000) notitle w yerrorbars ls 1, \
'' using ($1/1000):($2/1000000) title "Hlog" w lines ls 1,\
file2 using ($1/1000):($2/1000000):($3/1000000):($4/1000000) notitle w yerrorbars ls 2, \
'' using ($1/1000):($2/1000000) title "Iris" w lines ls 2,\
file3 using ($1/1000):($2/1000000):($3/1000000):($4/1000000) notitle w yerrorbars ls 3, \
'' using ($1/1000):($2/1000000) title "Java" w lines ls 3
Generally, you can get both lines and points, if you plot with the linespoints plotting style:
sc(x) = x*1e-6
plot file1 using ($1/1000):(sc($2)):(sc($3)):(sc($4)) notitle w yerrorbars ls 1 ps 0.5, \
'' using ($1/1000):(sc($2)) title "Hlog" w linespoints ls 1
That draws the points twice, which shouldn't be a problem unless you use transparency. I also shrinked the points which are drawn together with the errorbars to 50%, so you don't get problems with antialiasing.
As another option you could add the title only the the errorbars, in which case the legend would look like |---x---| (i.e. contain also the errorbars):
sc(x) = x*1e-6
plot file1 using ($1/1000):(sc($2)):(sc($3)):(sc($4)) title "Hlog" w yerrorbars ls 1, \
'' using ($1/1000):(sc($2)) notitle w lines ls 1

gnuplot png output doesn't plot dashed/dotted lines

I'm trying to plot a figure that contains both dashed and continuous lines with gnuplot v4.4 . The code is:
set term postscript eps enhanced color
set style line 1 linetype 1 lw 2
set style line 2 linetype 1 lw 2 linecolor rgb 'green'
set style line 3 linetype 1 lw 2 linecolor rgb 'blue'
set style line 4 linetype 4 lw 2 linecolor rgb 'red'
set style line 5 linetype 3 lw 2 linecolor rgb 'blue'
set border lw 3
set xtics font ',18'
set ytics font ',18'
set output 'roc.ps'
set key right bottom
plot 'roc_fpdock_isc_test' u 1:2 w l ls 1 title "Full optimization, test set" ,x w l ls 2 title "Random", 'roc_fpdock_isc_training' u 1:2 w l ls 3 title "Full optimization, training set", 'roc_mini_pep_sc_training' u 1:2 w l ls 4 title "Minimization only, training set", 'roc_mini_pep_sc_test' u 1:2 w l ls 5 title "Minimization only, test set"
Problem is , I can't plot it to png. When I change the set term instruction to: set term png enhanced I get only continuous lines.
Any idea what went wrong?
It turns out that I can't seem to get dashed lines in the png terminal either (the one with the GD backend). However, if you have the cairo terminals, you can get a png with dashed lines (assuming you pick the appropriate linetypes).
set term pngcairo dashed
set output "foo.png"
test
!display foo.png
!rm foo.png
As an aside, test is fantastic for inquiring what the behavior of a particular terminal will be.
You have the dt option for dashtype in pngcairo. Legend here:
e.g
set style line 5 linetype 3 dt 5 lw 3 linecolor rgb 'green'
gives dashtype 5

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