Draw two pointlines in a histogram (gnuplot)? - gnuplot

I want to draw two pointsline in a histogram by gnuplot, The result chart is not exactly what I wanted. Actually, I want points in two pointlines(the pink one and the lightgreen one) align the center of two types of pillars, so the lightgreen one keeps still, while the pink one move a little to the right, just like the black one I have drawn.
the 'test.dat' is as follow:
1 10 15 8 22
2 11 19 7 21
3 9 14 7 19
4 10 21 8 23
5 9 17 9 21
and the 'plt' file:
set style data histogram
unset key
set yrange[0:12]
set y2range[0:25]
plot "test.dat" using 2:xticlabel(1) axis x1y1,\
"test.dat" using 3:xticlabel(1) axis x1y2 with linespoints,\
"test.dat" using 4:xticlabel(1) axis x1y1,\
"test.dat" using 5:xticlabel(1) axis x1y2 with linespoints

My answer is based on this contribution which uses boxes instead of a histogram. The benefit is that, you know exactly where those boxes are placed, which you can exploit for the line plot.
Here's the code:
dx=1.
n=2.
total_box_width_relative=0.25
gap_width_relative=0.1
d_width=(gap_width_relative+total_box_width_relative)*dx/n
set boxwidth total_box_width_relative/n relative
set style fill transparent solid 0.5 noborder
plot "test.dat" u ($1):2 w boxes lc rgb"green" notitle,\
"test.dat" u ($1+d_width):4 w boxes lc rgb"red" notitle,\
"test.dat" u ($1):3 w linespoints notitle,\
"test.dat" u ($1+d_width):5 w linespoints notitle
set yrange [0:15]
replot
Some explanations to the code:
The dx should be selected according to your data file, otherwise the spacing of the boxes will be off.
The number of data-sets for the boxes is given by n
The total_box_width_relative and gap_width_relative control the axial with and spacing of the boxes
the two set ... commands control the appearance of your boxes
within the plot command you now have to separate: You call one set of boxes and lines with the original 1st column data: ($1), however, for the second set of boxes and the corresponding line, you choose your defined axial offset: ($1+d_width) - this will ensure that the data points from the line plot will align with the boxes
it may be necessary to include a set yrange command
The plot will look like this:
Note
I changed the data for the line plots with regard to the data you provided. This was done only to bring the points closer to the boxes and illustrate the effect.

Related

gnuplot histogram chart with overlap

I would like to plot a bar chart or histogram like this in gnuplot.
I tried set style histogram rowstacked which is a start but it adds the columns on top of each other while I need them overlapped. Next is the issue of transparent color shading.
Thanks for your feedback.
UPDATE: user8153 asked for additional data.
The set style histogram clustered gap 0.0 is doing the cluster mode of the histogram bars. If you blur the eye it sort-of shows what I want but with overlap and transparent shading.
The only other histogram modes given in the docs are rowstacked and columnstacked. I never got a plot out of columnstacked so I discarded it. Now rowstacked stacks the histogram bars.
The overlay appearance is there but it is wrong. I don't want the stacked appearance. The histograms have to overlay.
Code :
set boxwidth 1.0 absolute
set style fill solid 0.5 noborder
set style data histogram
set style histogram clustered gap 0.0
#set style histogram rowstacked gap 0.0
set xtics in rotate by 90 offset first +0.5,0 right
set yrange [0:8000]
set xrange [90:180]
plot 'dat1.raw' using 3 lc rgb 'orange', \
'dat2.raw' using 3 lc rgb 'blue', \
'dat3.raw' using 3 lc rgb 'magenta'
Thanks for your feedback.
Given a sample datafile test.dat
-10 4.5399929762484854e-05
-9 0.0003035391380788668
-8 0.001661557273173934
-7 0.007446583070924338
-6 0.02732372244729256
-5 0.0820849986238988
-4 0.20189651799465538
-3 0.4065696597405991
-2 0.6703200460356393
-1 0.9048374180359595
0 1.0
1 0.9048374180359595
2 0.6703200460356393
3 0.4065696597405991
4 0.20189651799465538
5 0.0820849986238988
6 0.02732372244729256
7 0.007446583070924338
8 0.001661557273173934
9 0.0003035391380788668
10 4.5399929762484854e-05
you can use the following commands
set style fill transparent solid 0.7
plot "test.dat" with boxes, \
"test.dat" u ($1+4):2 with boxes
to get the following result (using the pngcairo terminal):
Using transparency as in user8153's solution is certainly the easiest way to visualize an overlap of two histograms.
This works even if the two histogram do not have identical bins or x-data-ranges.
However, the color of the overlap is pretty much bound to the colors of the two histogram and the level of transparency. Furthermore, if you want to show the overlap in the key you have to do it "manually".
Here is a solution where you can choose an independent color for the overlap area.
The overlap is basically the minimum y-value from both histograms for each x-value.
For this you need to compare the y-values for each x-value. This can be done in gnuplot with some "trick" by merging the two files line by line. This requires the data in a datablock (how to get it there from a file). Since this merging procedure is using indexing of datablock lines, it requires gnuplot>=5.2.0.
This assumes that you have the same x-range and bins for each histogram. If this is not the case, you have to implement some further steps.
Script: (works with gnuplot>=5.2.0, Sept. 2017)
### plot overlap of two histograms
reset session
# create some random test data
set samples 21
f(x,a,b) = 1./(a*(x-b)**4+1)
set table $Data1
plot '+' u 1:(f(x,0.01,-2)) w table
set table $Data2
plot '+' u 1:(f(x,0.02,4)) w table
unset table
set boxwidth 1.0
set grid y
set ytics 0.2
set multiplot layout 2,1
set style fill transparent solid 0.3
plot $Data1 u 1:2 w boxes lc 1 ti "Data1", \
$Data2 u 1:2 w boxes lc 2 ti "Data2"
set print $Overlap
do for [i=1:|$Data1|] { print $Data1[i].$Data2[i] }
set print
set style fill solid 0.3
plot $Data1 u 1:2 w boxes lc 1 ti "Data1", \
$Data2 u 1:2 w boxes lc 2 ti "Data2", \
$Overlap u 1:($2>$4?$4:$2) w boxes lc "red" ti "Overlap"
unset multiplot
### end of script
Result:

Gnuplot: draw error bars of data points outside plotting range

If I set a specific yrange and plot in a pdf terminal with this plot command:
plot "data.dat" u 1:4:5:6 w yerrorbars pt 6 ps 0.5 t "R_t"
errorbars that belong to data points outside the yrange, but end inside the yrange are not shown.
How do I force gnuplot to draw those. I already tried "set clip one/two"
The only workaround I found is to plot the data 3 times, once for the central point and once for each side of the error bar.
Use "-" as symbol for the errorbars and use their own "errorbars" to draw a line to the central point.
You could use multiplot to achieve this.
Set your plot to have zero margins, so the axes are on the border of the canvas, and switch of all tics and borders for the first plot.
Switch on the axes, tics etc. again, and do an empty plot that you set at the correct position using set size and set origin. You'll have to do some math to calculate the exact position.
#MaVo159, you can reduce it to plotting only twice by using with yerrorbars and with vectors (check help vectors). You need to set the proper arrow style, check help arrowstyle.
However, this works only for gnuplot>=5.2.3, for earlier versions there seems to be a bug which plots the arrowhead at the wrong side for some of the vectors extending the graph.
You nevertheless have to plot once with yerrorbars in order to get the proper legend.
Script: (works for gnuplot>=5.2.3, May 2018)
### plot errorbars from points outside the range
reset
$Data <<EOD
1 9 5.11 8.32
2 8 6.20 9.22
3 6 5.31 6.31
4 5 4.41 5.51
5 4 3.31 4.71
6 2.9 2.81 3.71
7 2 1.11 3.41
EOD
set yrange[3:7]
set offsets 1,1,0,0
set style arrow 1 heads size 0.05,90 lw 2 lc 1
set multiplot layout 2,1
plot $Data u 1:2:3:4 w yerrorbars pt 6 ps 2 lw 2
plot $Data u 1:2:3:4 w yerrorbars pt 6 ps 2 lw 2, \
'' u 1:3:(0):($4-$3) w vec as 1 notitle
unset multiplot
### end of script
Result:
You could modify your data file: Because the central value of the data point is outside the plot range you could set it equal to the errorbar's end point that would be still visible in your plot.
Example:
plot range: set yrange[-2:2]
data point: 1, -3, -1, -4 (x, y, ylow, yhigh)
set data point to: 1, -1, -1, -4
Attention: Since you have to edit your data file you should
Make a copy of the original data file
Be very careful when editing the file
Keep in mind, that when changing the plot range such that the central
value of the data point becomes visible you have to use the original data point. Otherwise you will see the correct error bar but there will be no central value plotted. (this is equivalent to setting 'point type' to 0)

Displaying markers on specific values in Gnuplot's line plot

I have data for a CDF in a file which looks like the following:
0.033 0.0010718113612
0.034 0.0016077170418
0.038 0.0021436227224
... ...
... ...
0.847 0.999464094319
0.862 1.0
First column is the X-axis value and the second column is the CDF value on Y-axis. I set the line style as follows:
set style line 1 lc rgb 'blue' lt 1 lw 2 pt 7 ps 0.75 # --- blue
and subsequently plot the line with the following:
plot file1 using 1:2 title 'Test Line CDF' with linespoints ls 1
This all works fine, the problem seems to be that my CDF file is pretty big (about 250 rows) and Gnuplot would plot the marker/point (a circle in this case) for every data point. This results in a very "dense" line because of the over-concentration of markers such that the underlying line is almost not visible as I show in an example image below:
How can I selectively draw the markers so that instead of having them on all data points, I plot them after every 50 data points, without having to decrease the number of data points (which I believe is what "every n" in the plot command would do) in my data file or decrease the marker size?
There is no need to use two plots commands, just use the pointinterval option:
plot 'data' pointinterval 5 with linespoints
That plots every line segment, but only every fifth point symbol.
The big advantage is, that you can control the behaviour with set style line:
set style line 1 lc rgb 'blue' lt 1 lw 2 pt 7 ps 0.75 pi 5
plot 'data' w lp ls 1
You can plot the same function twice, once with lines only, and then with points every n points. This will draw less points without decreasing the amount of segments. I think this is what you want to achieve. For this example I have done set table "data" ; plot sin(x) to generate numerical sampling of the sin(x) function.
What you have at the moment is:
plot "data" with linespoints pt 7
which gives
Now you can do the following:
plot "data" with lines, "data" every 10 with points pt 7 lc 1
which gives what you want:
You can change the styling to meet your needs.
Although #Miguel beat me to it, but I'm also posting my solution below:
The idea is to once draw the line and then draw the points with the "every n" specifier. I changed my own Gnuplot script in the following manner. A kind of hack but works:
set style line 1 lc rgb 'blue' lt 1 lw 2 pt 7 ps 0 # --- blue
plot file1 using 1:2 title '' with linespoints ls 1, "" using 1:2 every 20 title 'Test Line CDF' with points ls 1 ps 0.75
This retains the nice curve, without quantizing it too coarsely while also keeping the points much better spaced.

Custom legend (or text) gnuplot

I have a file with 3 columns, the first 2 are the position x y and the 3rd one I use it for define the color so I have something like this:
set palette model RGB defined ( 1 'black', 2 'blue', 3 'green', 4 'red')
unset colorbox
plot "file" u 2:1:3 w points pt 14 ps 2 palette, "file2" u 2:1:3 w points pt 14 ps 2 palette
Now the question: Is it possible to have a proper legend with this kind of point and COLOR?.
Since the points will have different colors (according to the pallete) I want to specify what means each color in the legend.
The only solution I was thinking was to write somewhere in the plot some text with the character of the point (in this case pt 14) and specify the color... but is not really a solution right?
So please help!
There is no option for this, you need to fiddle a bit. Here is YAGH (Yet another gnuplot hack) ;)
Assuming that your values are equidistantly spaced, you can use the '+' special filename with the labels plotting style.
To show only the custom key, consider the following example:
labels="first second third fourth"
set xrange[0:1] # must be set for '+'
set yrange[0:1]
set samples words(labels) # number of colors to use
key_x = 0.8 # x-value of the points, must be given in units of the x-axis
key_y = 0.8
key_dy = 0.05
set palette model RGB defined ( 1 'black', 2 'blue', 3 'green', 4 'red')
unset colorbox
plot '+' using (key_x):(key_y + $0*key_dy):(word(labels, int($0+1))):0 \
with labels left offset 1,-0.1 point pt 7 palette t ''
This gives (with 4.6.4):
As the set samples doesn't affect the data plots, you can integrate this directly in your plot command:
...
unset key
plot "file" u 2:1:3 w points pt 14 ps 2 palette, \
"file2" u 2:1:3 w points pt 14 ps 2 palette, \
'+' using (key_x):(key_y - $0*key_dy):(word(labels, int($0+1))):0 \
with labels left offset 1,-0.1 point pt 14 ps 2 palette
But you need to set a proper xrange, yrange and the values of key_x, key_y and key_dy.
This is not the most intuitive way, but it works :)
I have an alternative solution posted here:
Using Gnuplot to plot point colors conditionally
Essentially you plot once without a legend entry, then make dummy plots (with no data) for each point color/label.

setting multiple labels at the top of the x-axis

After the answer got in my earlier post drawing vertical lines in between bezier curves, I have been trying to label the segments separated by the dotted lines. I used x2label but found out that if I use it multiple times then the data gets replaced though they are positioned in different places. Below is the script:
set term x11 persist
set title "Animation curves"
set xlabel "Time (secs.)"
set ylabel "Parameter"
set x2label "Phoneme1" offset -35
set pointsize 2
set key off
set style line 2 lt 0 lc 1 lw 2
plot [0.04:0.15] "curve.dat" u 1:2 smooth csplines ls 1, "" u 1:($2-0.2):(0):(0.3) w vectors nohead ls 2, \
"curve.dat" u 1:2 with points
The output is the following.
I want to label Phoneme1, Phoneme2...and so on.. on top of each segment. How would I do it? Also as I was suggested in my earlier post to play with the line "" u 1:($2-0.2):(0):(0.3) w vectors nohead ls 2 to get a top to bottom vertical lines. But that also did not work. How do I get the lines from top margin to bottom? Thank you.
The horizontal lines
The horizontal lines can be accomplished with setting the yrange to an explicit value. Otherwise gnuplot would try to get some space between the lines and the axis. You could choose the values
set yrange [0.3:1.2]
Then you simply modify the vector using directions like so:
"" u 1:(0.3):(0):(1.2) w vectors nohead ls 2
(see below for the complete script)
The labeling of the sections
A quick way of doing this with your set of data would be this:
set key off
set style line 2 lt 0 lc 1 lw 2
set yrange [0.3:1.2]
plot [0.04:0.15] "Data.csv" u 1:2 smooth csplines ls 1, \
"" u 1:(0.3):(0):(1.2) w vectors nohead ls 2, \
"" u ($1+0.005):(1):(sprintf("P %d", $0)) w labels
However, this will probably not look the way you want it to look. You could think of modifying your data file to also include some information about the labeling like:
#x-value y-value x-label y-label label
0.06 0.694821399177 0.65 0.1 Phoneme1
0.07 0.543022222222 0.75 0.1 Phoneme2
Then the labels line would simply look like:
"" u 3:4:5 w labels
The complete plot then looks like this:

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