Remove linespoints in Gnu plot - gnuplot

I have ploted a graph in Gnuplot with linespoint
gnuplot> plot "360 values.txt" title "Fidelity vs Time" lt 7 lc 0 w lp
Now I want to change the linespoints with only lines
so I used
gnuplot> plot "360 values.txt" title "Fidelity vs Time" lt 7 lc 0 lw 4 w lines
But now the whole graph disappeared.
Why?

Gnuplot does not connect points with lines if the points in the datafile are separated by empty lines.
From the documentation (help plot datafile):
...
In datafiles, blank records (records with no characters other than blanks and
a newline and/or carriage return) are significant.
Single blank records designate discontinuities in a `plot`; no line will join
points separated by a blank records (if they are plotted with a line style).
Two blank records in a row indicate a break between separate data sets.
See `index`.
...

Related

setting the linewidth in gnuplot when the color is given by a 4th axis

To plot 3D data xyz with the color given by a 4th variable I can use the command
splot 'au' u 1:2:3:4 linecolor palette with lines
where au is a file containing 4 columns of data.
If I try to adjust the width of the line to make it easier to see it gives the error below. What it the correct way to set the line width when taking colour from a palate given by a 4th axis
gnuplot> splot 'au' u 1:2:3:6 linecolor palette with lines lw 2
^
duplicated or contradicting arguments in plot options
Line properties must all come next to each other in the plot command; you can't stick something else (in this case with lines) in the middle. Use either
splot 'au' u 1:2:3:6 linecolor palette lw 2 with lines
or
splot 'au' u 1:2:3:6 with lines linecolor palette lw 2

Subtract smoothed data from original

I wonder whether there is a way to subtract smoothed data from original ones when doing things of the kind:
plot ["17.12.2020 08:00:00":"18.12.2020 20:00:00"] 'data3-17-28.csv1' using 4:5 title 'Sensor 3' with lines, \
'' using 4:5 smooth acsplines
Alternatively I would need to do it externally, of course.
As #Suntory already suggested you can plot smoothed data into a table.
However, keep in mind, the number of datapoints will be determined by set samples, default setting is 100 and the smoothed datapoints will be equidistant. So, if you set samples to the number of your datapoints and your data is equidistant as well, then all should be fine.
Concatenating data line by line is not straightforward in gnuplot, since gnuplot is not intended to do such operations.
The following gnuplot-only solution assumes that you have your data in a datablock $Data without headers and empty lines. If not, you could either plot it with table from file into a table named $Data or use the following approach in the accepted answer of this question: gnuplot: load datafile 1:1 into datablock
If you don't have equidistant data, you need to interpolate data, which is also not straightforward in gnuplot, see: Resampling data with gnuplot
It's up to you: either you use external tools (which might not be platform-independent) or you apply a somewhat cumbersome platform independent gnuplot-only solution.
Code:
### plot difference of data to smoothed data
reset session
$Data <<EOD
1 0
2 13
3 16
4 17
5 11
6 8
7 0
EOD
stats $Data u 0 nooutput # get number of rows or datapoints
set samples STATS_records
set table $Smoothed
plot $Data u 1:2 smooth acsplines
unset table
# put both datablock into one
set print $Difference
do for [i=1:|$Data|] {
print sprintf('%s %s',$Data[i],$Smoothed[i+4])
}
set print
plot $Data u 1:2 w lp pt 7, \
$Smoothed u 1:2 w lp pt 6, \
$Difference u 1:($2-$4) w lp pt 4 lc "red"
### end of code
Result:
If I well understand you would like this :
First write your smooth's data in out.csv file
set table "out.csv" separator comma
plot 'file' u 4:5 smooth acsplines
unset table
Then this line will paste 'out.csv' to file as an appended column.You will maybe need to delete first lines using sed command (sed '1,4d' out.csv)
stats 'file' matrix
Thanks to stats we automatically get the number of column in your original data (STATS_size_x).
plot "< paste -d' ' file out.csv" u 4:($5-$(STATS_size_x+2)) w l
Could you please try this small code on your data.

Gnuplot plotting wrong lines and some strange values as well

I am using gnuplot to postprocess some calculation that I have done and I am having hard time getting gnuplot to select the right lines as it is outputting some strange values that I do not know where come from.
The first 200 points of the results start in line 3 and stop in 202 but that is not working when I use every ::3::202.
Does anyone have any suggestions of what I am doing wrong?
Gnuplot image:
Datafile
set terminal pngcairo transparent nocrop enhanced size 3200,2400 font "arial,40"
set output "Mast41_voltage_muffe.png"
set key right
set samples 500, 500
set xzeroaxis ls 1 lt 8 lw 3
set style line 12 lc rgb '#808080' lt 0 lw 1
set style line 13 lt 0 lw 3
set grid back ls 12
set decimalsign '.'
set datafile separator whitespace
set ylabel "Spenna [pu]"
set xlabel "Timi [s]"
plot "mrunout_01.out" every ::3::202 using 2:3 title '5 ohm' with lines lw 3 linecolor rgb '#D0006E',\
"mrunout_01.out" every ::203::402 using 2:3 title '10 ohm' with lines lw 3 linecolor rgb '#015DD4',\
"mrunout_01.out" every ::403::602 using 2:3 title '15 ohm' with lines lw 3 linecolor rgb '#F80419',\
"mrunout_01.out" every ::603::802 using 2:3 title '20 ohm' with lines lw 3 linecolor rgb '#07826A'
unset output
unset zeroaxis
unset terminal
every refers to the actual plottable points. In your case, you have to skip 2 lines and the bunch of data at the end of your datafile.
Since you know the actual lines you need to plot I would pre-parse the file with some external tools like sed
So you can omit the every and your plot line becomes:
plot "< sed -n '3,202p' mrunout_01.out" using 2:3 title '5 ohm' with lp lw 3 linecolor rgb '#D0006E'
With yor datafile as it is, gnuplot has problems reading it. It can't even run stats on it:
stats 'mrunout_01.out'
bad data on line 1 of file mrunout_01.out
There is no need for using external tools, you can simply do it with gnuplot.
It's advantageous with your data that it is regular, every 200 points plotted in a different color.
And the data you want to plot is separated by one empty line from some additional data at the end of the file which you don't want to plot.
So, you simply address the 4th set of 200 lines in the 0th block via every ::600:0:799:0.
From help every:
Syntax:
plot 'file' every {<point_incr>}
{:{<block_incr>}
{:{<start_point>}
{:{<start_block>}
{:{<end_point>}
{:<end_block>}}}}}
Comments:
you can skip two lines at the beginning of the files with skip 2
you can plot your curves in a loop plot for [i=1:4] ...
you can define your color myColor(n) via index n from a string "#D0006E #015DD4 #F80419 #07826A"
you can define the legend myTitle(n) also from a list "5 10 15 20"
Script: (tested with gnuplot 5.0.0, version at the time of OP's question)
### plot parts of a file in a loop
reset session
FILE = "SO36103041.dat"
myColor(n) = word("#D0006E #015DD4 #F80419 #07826A",n)
myTitle(n) = word("5 10 15 20",n)
set xlabel "Timi [s]"
set ylabel "Spenna [pu]"
set yrange[0:30]
plot for [i=1:4] FILE u 2:3 skip 2 every ::((i-1)*200):0:(200*i-1):0 \
w l lw 3 lc rgb myColor(i) ti myTitle(i)
### end of script
Result:

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.

Gnuplot read line style from data file column

I'd like to draw an impulse graph from a text file that looks like this:
II 5 0 0 288.40 1.3033e+14
II 6 0 0 289.60 1.5621e+14
II 1 4 0 302.70 3.0084e+13
II 2 4 0 303.40 4.0230e+13
II 1 5 1 304.40 3.4089e+13
The plot conceptually should be plot "datafile.dat" using 5:6 w impulses ls $2.
Basically, given a previously defined set of line styles, I'd like to input the line style number from column 2 for every couple of plotted points from column 5 and 6.
Also I'd like to create a text box, for every plotted point, taking strings from the first four columns.
Does somebody know if that's possible?
To use the data from column two as line style use set style increment user and linecolor variable:
set style increment user
plot "datafile.dat" using 5:6:2 with impulses lc var
In order to place a label, use the labels plotting style:
plot "datafile.dat" using 5:6:1 with labels offset 0,1
Putting everything together, you have:
set style increment user
set for [i=1:6] style line i lt i
set yrange [0:*]
set offsets 0,0,graph 0.1,0
plot "datafile.dat" using 5:6:2 with impulses lc var, "" using 5:6:1 with labels offset 0,1
The result with 4.6.3 is:
Thanks for the helpful answer above. It almost solved my problem
I'm actually trying to use a column from my data file to specify a linestyle (dot, squares,triangles, whatever as long as it's user-defined), and not a linecolor. Is there any way to do that?
This line works : I get points with different colors (specified in column 4), but the point style is the same.
plot "$file" u 1:2:4 w p notitle lc var, "" using 1:2:3 with labels offset 0,1 notitle
Replacing lc with ls after defining my own styles doesn't work (ls can't have variable as an option)
I can live without different linestyles, but it would be much prettier.
You only have to replace the lineset for [i=1:6] style line i lt i for set for [i=1:6] style line i lt i pt %, Where % can be any type of point you want

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