How to plot histogram using gnuplot - shell

I have a file contains wire length ranging from 300-1000. How do I use GNUPLOT to make a histogram with length on X-axis (With interval of 100) and number of wires on Y-axis?
For example:
250 wire_0
350 wire_1
360 wire_2
800 wire_3
I want a bar with height of 1 representing wire_0, a bar with height of 2 representing wire_1 and wire_2 and a bar with height of 1 representing wire_3.

Edit #1
Based on both this and this answers, your could try:
binwidth = 100
bin(x, width) = width*floor(x/width)
set tics out nomirror
set style fill transparent solid 0.5 border lt -1
set xrange [0:1000]
set xtics binwidth
set boxwidth binwidth
set yrange [0:3]
$data <<EOD
250 wire_0
350 wire_1
360 wire_2
800 wire_3
EOD
plot $data u (bin($1,binwidth)):(1.0) smooth freq with boxes notitle
Result
Edit #2
If you need the of values above the boxes, you can use.
set table $data2
plot $data u (bin($1,binwidth)):(1.0) smooth freq with boxes;
unset table
plot $data2 u 1:2 w boxes notitle , "" u 1:2:2 w labels offset 0,1 notitle
Result

Related

Animation with gnuplot : only one cruve plotted in an animation whereas 2 expected

I have the following script which is expected to produce the animations of 2 curves :
#!/bin/bash
for i in {1..397}; do
gnuplot -p <<-EOFMarker
set terminal png;
set output "pic$i.png";
set title "power spectrum";
set xlabel "scale (k)";
set ylabel "P(k)";
set key top left;
set grid;
set ytics out nomirror;
set xtics out nomirror;
set logscale x;
set logscale y;
set format x "10^{%L}";
set yrange [0:30000];
plot "CAMB-1.3.5/matter_camb$i" u 1:2 w l;
replot "EFTCAMB_v3_beta/matter_eftcamb$i" u 1:2 w l;
EOFMarker
done
# Build movie with ffmpeg
ffmpeg -start_number 1 -i pic%d.png movie.mpeg
Every works fine excepted the fact that only one curve is plotted in animation (CAMB-1.3.5) :
Here is an example of frame :
Why the "replot" command is not taken into account in the generated image ?
Just for the sake of the SO-rule "no answer in comments":
Check help plot:
Syntax:
plot {<ranges>} <plot-element> {, <plot-element>, <plot-element>}
Examples:
plot sin(x)
plot sin(x), cos(x)
plot f(x) = sin(x*a), a = .2, f(x), a = .4, f(x)
plot "datafile.1" with lines, "datafile.2" with points
plot [t=1:10] [-pi:pi*2] tan(t), \
"data.1" using (tan($2)):($3/$4) smooth csplines \
axes x1y2 notitle with lines 5
plot for [datafile in "spinach.dat broccoli.dat"] datafile

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 automatically
You need to know the order of magnitude before you are plotting. You can get this via stats. Then divide your y-values by a factor which (in the example below) is chosen such that the axis tics should show values between 0 and 100.
The code:
### automatic prefactor in axis scaling and axis label
reset session
# generate some random data
set samples 20
RandomMagnitude = floor(rand(0)*20-10)
RandomValue = rand(0)
set table $Data
plot '+' u 0:(RandomValue*10**RandomMagnitude/($0)) with table
unset table
# get the maximum via stats
stats $Data u 2 nooutput
Max = STATS_max
PrefactorLog = ceil(log10(Max))-2
Prefactor = 10**PrefactorLog
set ylabel sprintf("Y-title, x 10^{%d} units",PrefactorLog)
set format y "%g"
set boxwidth 0.7 relative
plot $Data u 1:($2/Prefactor) with boxes fs solid 1.0 fc rgb "red" ti sprintf("Max value %.2e", Max)
### end of code
The result:

Centering labels on a pie chart

I am following this post to make a pie chart using Gnuplot. The only problem with the approach is that I can't align my percentage labels. What am I missing here?
DATA FILE:
"Others" 1.085117e-01 3.904323e-02
"D_o" 2.894902e-01 6.145359e-01
"{/Symbol b}_o" 5.760601e-01 3.760299e-01
"O_h" 5.393108e-01 1.000000e+00
"D_p" 6.743313e-01 2.284404e-01
"{/Symbol a}_p" 1.000000e+00 1.271822e-01
"{/Symbol b}_f" 4.020115e-01 2.233656e-01
"D_m" 2.389996e-01 8.577689e-02
"{/Symbol a}_m" 3.601146e-01 1.033153e-01
"{/Symbol b}_m" 5.596836e-01 1.947165e-01
CODE:
#!/usr/bin/gnuplot
# Terminal & Encoding
set terminal epscairo enhanced color dashed rounded size 8.5, 4.5
set output 'mu_piechart.eps'
set termoption enhanced
set encoding utf8
# Get Status
filename = './datafile.dat'
stats filename u 2 noout
# Get Angles & Percentages
ANG(x)=x*360.0/STATS_sum
PER(x)=x*100.0/STATS_sum
# Square Canvas
set size square
set xrange [-1:1.5]
set yrange [-1.25:1.25]
set style fill solid 1
# Remove Base Properties (Titles, Tics, Axis, Palette)
unset key
unset tics
unset border
unset colorbox
# Initial Angle, Mid Angle, Initial Color
A = 0.0; M = 0.0; i = 0;
# Palette
set palette defined (1 1 0.788 0.055, 2 0.090 0.161 0.659)
# Plot
plot for [i=0:STATS_records-1] filename u (0):(0):(1):(A):(A=A+ANG($2)):(i) every ::i::i with circle linecolor palette,\
filename u (M=A+ANG($2), A=2*M-A, M=M*pi/360.0, -0.5*cos(M)):(-0.5*sin(M)):(PER($2) > 8.00 ? sprintf('%.1f\%', PER($2)) : " ") every ::1 w labels center font ',10',\
for [i=0:STATS_records-1] filename u (1.45):(i*0.25)-1.11:($1) every ::i::i with labels left,\
for [i=0:STATS_records-1] '+' u (1.3):(i*0.25)-1.11:(i) pt 5 ps 4 lc palette
exit
OUTPUT:
The percentages positions are not correct in the figure generated by the script.
Your labels are at wrong positions, because your label plot starts at 1, i.e. you skip the first entry.
Also, what I don't understand is, why you plot the pie parts counterclockwise, and the labels clockwise.
Here is a working version of you script, without some parts which are superfluous for demonstration. Both labels and pie parts are plotted starting at an angle of A = 0 (note the second initialization between the two plots):
reset
# Get Status
filename = './datafile.dat'
stats filename u 2 noout
# Get Angles & Percentages
ANG(x)=x*360.0/STATS_sum
PER(x)=x*100.0/STATS_sum
# Y position of key point and label
YLBL(row) = 2.0 * (row - 0.5*(STATS_records - 1))/(STATS_records - 1)
# Square Canvas
set size square
set xrange [-1:1.5]
set yrange [-1.25:1.25]
set style fill solid 1
# Remove Base Properties (Titles, Tics, Axis, Palette)
unset key
unset tics
unset border
unset colorbox
# Palette
set palette defined (1 1 0.788 0.055, 2 0.090 0.161 0.659)
# Plot
A = 0.0
plot filename u (0):(0):(1):(A):(A=A+ANG($2)):0 with circle linecolor palette,\
A = 0,\
filename u (M=A+ANG($2), A=2*M-A, M=M*pi/360.0, 0.5*cos(M)):(0.5*sin(M)):(PER($2) > 8.0 ? sprintf('%.1f\%', PER($2)) : "" ) w labels center,\
filename u (1.3):(YLBL($0)):1 with labels offset char 3 left ,\
filename u (1.3):(YLBL($0)):0 pt 5 ps 4 lc palette
The script contains some other improvements:
You don't need to iterate over STATS_records
The text and point for the key are plotted at the same position, the label is shifted with the offset parameter by three character units (offset char 3). That makes fine-tuning easier.

Trouble with plot matrix with image and xrange

I have trouble with xrange. When I put 'set autoscale xfix' image is ok but information axis not. When i put xrange [-1:1] i get info ok but images is damage. Second trouble is flip image. In my data stored in file upper left corner is -1 on image is +1, why?
my data is:
-0.999770 -0.998743 0.946455 0.999678 0.999777
-0.699447 -0.999784 -0.999565 -0.076214 0.999467
0.999921 -0.717181 -0.999790 -0.999734 -0.959481
0.999943 0.999920 -0.733798 -0.999793 -0.999786
0.999943 0.999943 0.999920 -0.749453 -0.999794
my code is:
set terminal png transparent enhanced font "arial,10" fontscale 1.0 size 600, 400
set output 'out.png'
set xtics 0.25
set ytics 0.25
set xrange [-1:1]
set yrange [-1:1]
set cbrange [-1:1]
plot 'data.txt' matrix with image
My image is -1 to 1 step 0.5
if I add set xrange [-1:1] and set yrange [-1:1] I get
$ gnuplot -V
gnuplot 5.0 patchlevel 3
the thing is that your data file is interpreted as a uniform matrix. In this case:
gnuplot> help matrix
Gnuplot can interpret matrix data input in two different ways.
The first of these assumes a uniform grid of x and y coordinates and assigns
each value in the input matrix to one element M[i,j] of this uniform grid.
The assigned x coordinates are the integers [0:NCOLS-1].
The assigned y coordinates are the integers [0:NROWS-1].
So this means that the datapoints in the first row of your file will have y-coordinate set to 0, second row 1, etc. However, since the y-axis by default points upwards, the resulting image is therefore flipped. Also, these points define the centers of the elementary color squares/boxes in the plot. So that's way the "effective x/y-range" is in your case [-0.5:4.5].
To "fix" the y-axis, you could use
set yr [] reverse
Here, [] specifies that the axis is still autoscaled.
Finally, to rescale your image from [0,4] into the [-1,1] range, you could use:
fn(x) = x/2. - 1
plot 'data.txt' matrix u (fn($1)):(fn($2)):3 w image
So in total:
set terminal png transparent enhanced font "arial,10" fontscale 1.0 size 600, 400
set output 'out.png'
set xtics 0.25
set ytics 0.25
set xrange [-1:1]
set yrange [-1:1] reverse
set cbrange [-1:1]
fn(x)=x/2-1
plot 'data.txt' matrix u (fn($1)):(fn($2)):3 w image
EDIT:
One could also adapt the script above to deal with a matrix of a priori unknown size:
set terminal png transparent enhanced font "arial,10" fontscale 1.0 size 600, 400
set output 'out.png'
set xrange [-1:1]
set yrange [-1:1] reverse
set cbrange [-1:1]
fName = 'data.txt'
stats fName nooutput
N = STATS_records - 1
set xtics 1./N
set ytics 1./N
fn(x)=(2*x/N)-1
plot fName matrix u (fn($1)):(fn($2)):3 w image
Here, the stats command first scans the file and stores the number of records into a special variable STATS_records. The function fn then rescales the range [0:STATS_records-1] on [-1:1]. Also, the x/y-tics are adapted automatically.

z-range threshold for matrix heat map in Gnuplot

Background:
I have a cross-correlation matrix of rows i and columns j with only z values ranging between -1 and 1. I'm able to output a nice heat map using the following script:
unset key
set tic scale 1
set xtics out
set ytics out
set palette defined (-1 "red", 0 "white", 1 "blue")
set cbrange [-1:1]
set cblabel "Correlation Function"
unset cbtics
set size ratio 1
set xrange [0:588]
set yrange [0:588]
set view map
splot 'file.dat' matrix with image
The Problem:
I want to 'screen out' certain z values, such that -0.50 ≤ z ≤ 0.50 are not taken into account for plotting.
Had a think about this some more, and took onboard the advice offered by Christoph. To achieve what I wanted I changed line from:
set palette defined (-1 "red", 0 "white", 1 "blue")
...to:
set palette defined (-1 "red", -0.5, "white", 0.5 "white", 1 "blue")
Worked like a charm.

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