I am trying to draw a rudimentary line segment from (0,0) to (0,1). I already have an input file, but I want to add a line to it.
I have read through Line plot in GnuPlot where line width is a third column in my data file? and Plot line segments from a datafile with gnuplot among many other examples. Everyone is doing something much more complex than what I want, I only want the line segment added to my GNUPlot script.
I normally enter the data in to GNUPlot thus:
$DATA << EOD
.... other data
EOD
$LS << EOL
0 0
0 1
EOL
plot $DATA using 1:2:3 with points
plot $LS with lines
but this doesn't work, nor does
plot $LS using 1:2 with lines
How can I plot this simple line segment from (0,0) to (0,1)?
What does "doesn't work" mean? You don't even show the resulting graph. By the way what do you use the 3rd column for?
Your first example will make a plot only with your data and then a new plot with only the line segment.
And in your second example, the line from 0,0 to 0,1 in your plot is identical with the y-axis and therefore hard to see as long as the xrange starts from 0. You can easily check this, e.g. if you set the color to red or linewidth to 3 , e.g.
plot $LS u 1:2 lc "red" lw 3
You also can make your line segment "visible" if you set xrange[-0.2:]. Check the following example
Code:
### plotting simple line segments
reset session
$DATA << EOD
0.1 0.2 1
0.3 0.4 2
0.5 0.6 3
0.7 0.5 4
EOD
$LS1 << EOL
0 0
0 1
EOL
$LS2 <<EOL
0 0
1 1
EOL
set xrange [-0.2:]
plot $DATA using 1:2:3 with points pt 7, \
$LS1 u 1:2 with lines, \
$LS2 u 1:2 with lines
### end of code
Result:
You can use headless arrows to plot arbitrary line segments.
set xrange [0:1]
set yrange [0:1]
set arrow 1 from 0,0 to 0,1 nohead lw 3 lc 2
set arrow 2 from 0,0 to 1,1 nohead lw 2
plot NaN t''
Related
I'm using Gnuplot Version 5.2 patchlevel 6 on Debian 10. The following program
$d << EOD
1 0.5 0.1
2 0.75 0.2
3 0.99 0.5
4 1.25 1.1
EOD
plot $d using 1:2:3 w lines lc palette z lw 2
produces an expected output:
But if I change the last line to
plot $d using 1:2:3 w steps lc palette z lw 2
I receive an error message:
line 7: Too many using specs for this style
According to paragraphs II Plotting Styles, Steps in Gnuplot User Manual
The input column requires are the same as for plot styles lines and points.
and in paragraph II Plotting Styles, Lines stated that:
The basic form requires 1, 2, or 3 columns of input data. Additional input columns may be used to provide information such as variable line color
What am I doing wrong?
If you are drawing with steps, the question probably is: which color should the vertical lines have?
Quickly checking the documentation I couldn't find a hint whether variable line color together with steps explicitely works or explicitely doesn't work.
In any case, you can workaround with the following code:
Code:
### plotting with steps and variable line color
reset session
$Data <<EOD
1 0.5 0.1
2 0.75 0.2
3 0.99 0.5
4 1.25 1.1
EOD
set xrange [0:5]
set yrange [0:1.5]
plot x1=y1=NaN $Data u (x0=x1,x1=$1,x0):(y0=y1,y1=$2,y0):(x1-x0):(0):3 w vectors lw 2 lc palette nohead notitle, \
x1=y1=NaN $Data u (x0=x1,x1=$1,x1):(y0=y1,y1=$2,y0):(0):(y1-y0):3 w vectors lw 2 lc palette nohead notitle
### end of code
Result:
Addition: (vertical lines with variable colors)
Maybe you noticed that with your 4 datapoints there are only 3 colors. This is obvious, because if you have 4 data points you will only have 3 connecting lines, hence 3 colors.
A variation would be the following:
Draw your 4 points with the color according to the value column 3 and the same color for the horizontal lines.
However, for the vertical lines you split the lines into as many levels you want (here: myLevels = 20) using the color according to the palette.
Code:
### plotting with steps and variable line color (vertical lines with variable color)
reset session
$Data <<EOD
1 0.5 0.1
2 0.75 0.2
3 0.99 0.5
4 1.25 1.1
EOD
set xrange [0:5]
set yrange [0:1.5]
myLevels = 20
plot x1=y1=c1=NaN $Data u (x0=x1,x1=$1,x0):(y0=y1,y1=$2,y0):(x1-x0):(0):(c0=c1,c1=$3,c0) w vectors lw 2 lc palette nohead notitle, \
for [i=0:myLevels-1] x1=y1=NaN $Data u (x0=x1,x1=$1,x1):(y0=y1,y1=$2,y0+(y1-y0)*i/myLevels):(0):((y1-y0)/myLevels):(c0=c1,c1=$3,c0+(c1-c0)*i/myLevels) w vectors lw 2 lc palette nohead notitle, \
$Data u 1:2:3 w p pt 7 ps 2 lc palette notitle
### end of code
Result:
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:
I have x,y values for points in the first 2 colums and a number that indicates the point type (symbol) in the 3. column, in one data file. How do I plot data points with different symbols?
Unfortunately, there isn't a way (AFAIK) to automatically set the point of the plot from a column value using vanilla GNUPLOT.
However, there is a way to get around that by setting a linestyle for each data series, and then plotting the values based on that defined style:
set style line 1 lc rgb 'red' pt 7 #Circle
set style line 2 lc rgb 'blue' pt 5 #Square
Remember that the number after pt is the point-type.
Then, all you have to do is plot (assuming that the data in "data.txt" is ordered ColX ColY Col3):
plot "data.txt" using 1:2 title 'Y Axis' with points ls 1, \
"data.txt" using 1:3 title 'Y Axis' with points ls 2
Try it here using this data (in the section titled "Data" - also note that column 3 "Symbol" is noted used, it's mainly there for illustrative purposes):
# This file is called force.dat
# Force-Deflection data for a beam and a bar
# Deflection Col-Force Symbol
0.000 0 5
0.001 104 5
0.002 202 7
0.003 298 7
And in the Plot Script Heading:
set key inside bottom right
set xlabel 'Deflection (m)'
set ylabel 'Force (kN)'
set title 'Some Data'
set style line 1 lc rgb 'red' pt 7
set style line 2 lc rgb 'blue' pt 5
plot "data.txt" using 1:2 title 'Col-Force' with points ls 1, \
"data.txt" using 1:3 title 'Beam-Force' with points ls 2
The one caveat is of course that you have have to reconfigure your data input source.
REFERENCES:
http://www.gnuplotting.org/plotting-single-points/
http://www.gnuplotting.org/plotting-data/
Here is a possible solution (which is a simple extrapolation from gnuplot conditional plotting with if), that works as long as you don't have tens of different symbols to handle.
Suppose I want to plot 2D points in a coordinate system. I have only two symbols, that I arbitrarily represented with a 0 and a 1 in the last column of my data file :
0 -0.29450470209121704 1.2279523611068726 1
1 -0.4006965458393097 1.0025811195373535 0
2 -0.7109975814819336 0.9022682905197144 1
3 -0.8540692329406738 1.0190201997756958 1
4 -0.5559651851654053 0.7677079439163208 0
5 -1.1831613779067993 1.5692367553710938 0
6 -0.24254602193832397 0.8055955171585083 0
7 -0.3412654995918274 0.6301406025886536 0
8 -0.25005266070365906 0.7788659334182739 1
9 -0.16853423416614532 0.09659398347139359 1
10 0.169997438788414 0.3473801910877228 0
11 -0.5252010226249695 -0.1398928463459015 0
12 -0.17566296458244324 0.09505800902843475 1
To achieve what I want, I just plot my file using conditionals. Using an undefined value like 1/0 results in no plotting of the given point:
# Set styles
REG_PTS = 'pointtype 7 pointsize 1.5 linecolor rgb "purple"'
NET_PTS = 'pointtype 4 pointsize 1.5 linecolor rgb "blue"'
set grid
# Plot each category with its own style
plot "data_file" u 2:($4 == 0 ? $3 : 1/0) title "regular" #REG_PTS, \
"data_file" u 2:($4 == 1 ? $3 : 1/0) title "network" #NET_PTS
Here is the result :
Hope this helps
Variable pointype (pt variable) was introduced (I guess) not until gnuplot 5.2.0 (Sept 2017) (check help points).
Just in retrospective, another (awkward) solution would be the following for those who are still using such early versions.
Data:
1 1.0 4 # empty square
2 2.0 5 # filled square
3 3.0 6 # empty circle
4 4.0 7 # filled circle
5 5.0 8 # empty triangle up
6 6.0 9 # filled triangle down
7 7.0 15 # filled pentagon (cross in gnuplot 4.6 to 5.0)
Script: (works from gnuplot>=4.6.0, March 2012; but not necessary since 5.2.0)
### variable pointtype for gnuplot>=4.6
reset
FILE = 'SO23707979.dat'
set key noautotitle
set offsets 1,1,1,1
set pointsize 4
stats FILE u 0 nooutput
N = STATS_records # get the number of rows
p0=x1=y1=NaN
plot for [n=0:N-1 ] FILE u (x0=x1, x1=$1, x0):(y0=y1, y1=$2, y0):(p0=$3) \
every ::n::n w p pt p0 lc rgb "red", \
FILE u 1:2 every ::N-1::N-1 w p pt p0 lc rgb "red"
### end of script
Result:
Can gnuplot calculate the distance between two lines or maybe two points?
I'm having a plot where two (main) lines are plotted. For the moment let's assume that the first line is always above the second one. Is there a way to calculate the distance from line 2 to line 1 at a given x-value?
here is a picture of what my plot looks like and which distance I want to calculate:
The vertical lines are just for style and have nothing to do with the actual plot, their data is stored in test.dat and test2.dat.
My data-files of the lines look like this:
line1
0 118.1
2.754 117.77
4.054 117.64
6.131 116.17
7.7 116.04
8.391 115.36
10.535 115.25
11.433 116.03
12.591 116.22
19.519 118.59
line2
19.4 118.51
15.2 116.56
10.9 115.94
10.35 114.93
9.05 114.92
8.3 115.9
5.9 116.19
4.2 116.62
2.2 117.66
-0.3 118.06
My plotting-code looks like this:
set term wxt enhanced
cd 'working directory'
unset key
set size 0.9,0.9
set origin 0.1,0.1
set title 'TITLE'
unset border
set label 21 " rotate by 45" at -3.0,0.0 rotate by 45 point ps 2
set xrange [0:19.519]
set yrange [110:119]
set xtics nomirror(0, 2.745, 4.054, 6.131, 7.7, 8.391, 10.535, 11.433, 12.591, 19.519) rotate by 90 offset 0,-0.1 right
set ytics " ", 30000
plot "line1.dat" using ($1):($2):2 with labels offset 1, 1.8 rotate by 90, "line1.dat" using 1:2 with lines lt 1 lw 1 lc rgb '#000000', +112 lt 1 lw 1 lc rgb '#000000' , 'test.dat' with lines lt 1 lw 1 lc rgb '#000000', +110 lt 1 lw 1 lc rgb '#000000', 'line2.dat' with lines lt 0.5 lw 1 lc rgb '#000000', 'test2.dat' with lines lt 0.5 lw 1 lc rgb '#000000'
You can measure the distance manually. Move the mouse to the first point and type 'r'. Then as you move the mouse around, the x and y offsets, distance and angle are displayed. Type '5' to draw a line segment and to toggle between degrees and tangent display. Zooming in beforehand increases accuracy.
By the way, typing 'h' in the plot window will display a list of keybindings to the console.
An answer to this "rather old" question still might be of interest to OP, if not, maybe to others.
Yes, you can calculate and plot the difference of two lines. It requires some linear interpolation. Simply assign the desired x-value to the variable myX.
Data:
SO17717287_1.dat
0 118.1
2.754 117.77
4.054 117.64
6.131 116.17
7.7 116.04
8.391 115.36
10.535 115.25
11.433 116.03
12.591 116.22
19.519 118.59
SO17717287_2.dat
19.4 118.51
15.2 116.56
10.9 115.94
10.35 114.93
9.05 114.92
8.3 115.9
5.9 116.19
4.2 116.62
2.2 117.66
-0.3 118.06
Script: (works for gnuplot>=4.6.0)
### calculating and plotting a difference between two curves
reset
FILE1 = "SO17717287_1.dat"
FILE2 = "SO17717287_2.dat"
set border 1
unset key
set origin 0.05,0.05
set size 0.9,0.8
set xrange [0:19.519]
set xtics nomirror rotate by 90 offset 0,-0.1 right
set yrange [110:119]
unset ytics
myX = 15.2
getYa(xi) = (x0=x1, x1=$1, y0=y1, y1=$2, x1==xi ? ya=y1 : (sgn(x0-xi)!=sgn(x1-xi)) ? ya=(y1-y0)/(x1-x0)*(xi-x0)+y0 : NaN)
getYb(xi) = (x0=x1, x1=$1, y0=y1, y1=$2, x1==xi ? yb=y1 : (sgn(x0-xi)!=sgn(x1-xi)) ? yb=(y1-y0)/(x1-x0)*(xi-x0)+y0 : NaN)
set samples 2 # set to minimal possible value for plotting '+'
plot x1=y1=NaN FILE1 u 1:2:2:xtic(1) w labels offset 0,0.5 left rotate by 90, \
'' u 1:(getYa(myX),$2) w l lc rgb 'black', \
'' u 1:2:(0):(110-$2) w vec lt 0 nohead, \
+112 w l lc rgb 'black', \
x1=y1=NaN FILE2 u 1:(getYb(myX),$2) w l lt 0 lc rgb 'black', \
'+' u (myX):(ya):(0):(yb-ya) w vec heads lc rgb "red", \
'+' u (myX):(ya):(sprintf("%.3f",yb-ya)):xtic(sprintf("%g",myX)) w labels tc rgb "red" offset 0,1, \
'+' u (myX):(ya):(0):(110-ya) w vec nohead lt 0 lc rgb "red"
### end of script
Result: (created with gnuplot 4.6.0)
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.