I have two time-domain signals. Now I want to plot the range 10..20 seconds from signal 1 and the range 12...22 seconds from signal 2 in a single plot. However, I tried it this way, which fails:
plot [10:20] 'signal1.txt' using 1:2 with line lt -1 lw 1 fc rgb "black" title 'Signal 1',\
[12:22] 'signal2.txt' using 1:2 with line lt -1 lw 1 fc rgb "black" title 'Signal 2'
gnuplot says "invalid expression" for to the second range definition ([12:22]).
Any ideas?
If one tries
plot [3:6] sin(x), [-2:8] cos(x)
it's easy to realize that the only interval that counts is the first one.
To achieve his/her intent the OP may recur to an external program or use something similar to
set xrange [-10:10]
plot x<3?1/0:x<=6?sin(x):1/0, x<-2?1/0:x<=8?cos(x):1/0
The external program could simply be a shell script that leverages on awk to filter not interesting abscissae.
It's relatively easy to map my proposal to OP requirements
plot 's1' using 1:($1<10?1/0:$1<=20?$2:1/0) w l, 's2' using 1:($1<14?1/0:$1<=22?$2:1/0) w
Related
I know that I can control point interval by "pointinterval" or "pi" command. However, this command only works with "linespoint" or "lp" plotting style.
Can I manage point interval with "points" or "p" plotting style?
For example:
plot data u 1:2 w p pt 7 ps 1 pi 2000 lc rgb "red" title "density"
Here, I tried "pi 2000" for point interval with points plotting style but it is not working
In the points plotting style, you can control which data points to plot in regular intervals with the 'every' keyword. It goes right after the data file name. If you really wanted to only plot every 2000 data points:
plot "dataFile" every 2000 u 1:2 w p pt 7 ps 1 lc rgb "red" title "density"
"every" is quite sophisticated. Type 'help every' at a gnuplot prompt and you can get more details.
I would like to draw a line with plots that contain "jumping" values.
Here is an example: when we have plots of sin(x) for several cycles and plot it, unrealistic line will appear that go across from right to left (as shown in following figure).
One idea to avoid this might be using with linespoints (link), but I want to draw it without revising the original data file.
Do we have simple and robust solution for this problem?
Assuming that you are plotting a function, that is, for each x value there exists one and only one corresponding y value, the easiest way to achieve what you want is to use the smooth unique option. This smoothing routine will make the data monotonic in x, then plot it. When several y values exist for the same x value, the average will be used.
Example:
Data file:
0.5 0.5
1.0 1.5
1.5 0.5
0.5 0.5
Plotting without smoothing:
set xrange [0:2]
set yrange [0:2]
plot "data" w l
With smoothing:
plot "data" smooth unique
Edit: points are lost if this solution is used, so I suggest to improve my answer.
Here can be applied "conditional plotting". Suppose we have a file like this:
1 2
2 5
3 3
1 2
2 5
3 3
i.e. there is a backline between 3rd and 4th point.
plot "tmp.dat" u 1:2
Find minimum x value:
stats "tmp.dat" u 1:2
prev=STATS_min_x
Or find first x value:
prev=system("awk 'FNR == 1 {print $1}' tmp.dat")
Plot the line if current x value is greater than previous, or don't plot if it's less:
plot "tmp.dat" u ($0==0? prev:($1>prev? $1:1/0), prev=$1):2 w l
OK, it's not impossible, but the following is a ghastly hack. I really advise you add an empty line in your dataset at the breaks.
$dat << EOD
1 1
2 2
3 3
1 5
2 6
3 7
1 8
2 9
3 10
EOD
plot for [i=0:3] $dat us \
($0==0?j=0:j=j,llx=lx,lx=$1,llx>lx?j=j+1:j=j,i==j?$1:NaN):2 w lp notit
This plots your dataset three times (acually four, there is a small error in there. I guess i have to initialise all variables), counts how often the abscissa values "jump", and only plots datapoints if this counter j is equal to the plot counter i.
Check the help on the serial evaluation operator "a, b" and the ternary operator "a?b:c"
If you have data in a repetitive x-range where the corresponding y-values do not change, then #Miguel's smooth unique solution is certainly the easiest.
In a more general case, what if the x-range is repetitive but y-values are changing, e.g. like a noisy sin(x)?
Then compare two consecutive x-values x0 and x1, if x0>x1 then you have a "jump" and make the linecolor fully transparent, i.e. invisible, e.g. 0xff123456 (scheme 0xaarrggbb, check help colorspec). The same "trick" can be used when you want to interrupt a dataline which has a certain forward "jump" (see https://stackoverflow.com/a/72535613/7295599).
Minimal solution:
plot x1=NaN $Data u 1:2:(x0=x1,x1=$1,x0>x1?0xff123456:0x0000ff) w l lc rgb var
Script:
### plot "folded" data without connecting lines
reset session
# create some test data
set table $Data
plot [0:2*pi] for [i=1:4] '+' u 1:(sin(x)+rand(0)*0.5) w table
unset table
set xrange[0:2*pi]
set key noautotitle
set multiplot layout 1,2
plot $Data u 1:2 w l lc "red" ti "data as is"
plot x1=NaN $Data u 1:2:(x0=x1,x1=$1,x0>x1?0xff123456:0x0000ff) \
w l lc rgb var ti "\n\n\"Jumps\" removed\nwithout changing\ninput data"
unset multiplot
### end of script
Result:
I am plotting two graphs using gnuplot. First plot is actual data and the second one is the fitting of the data.
The script I used for plotting this is shown here below:
#!/usr/bin/gnuplot
reset
set terminal png enhanced
set terminal pngcairo enhanced color dashed
set output 'msd-maltoLyo12per-225ns.png'
##########################################
set macros
labelSIZE="font 'Arial,24'"
ticFONT="font 'Arial,16"
set key font 'Arial,14'
set key spacing 1.5 samplen 5
##########################################
set xrange [0:225]
set yrange [0:11000]
set xtic #ticFONT
set ytic #ticFONT
set xtics out nomirror
set ytics out nomirror
##############################
set style line 1 lt 1 lc rgb "red" lw 2.0
set style line 2 lt 2 lc rgb "blue" lw 2.0
set style line 3 lt 3 lc rgb "coral" lw 2.0
set style line 4 lt 4 lc rgb "green" lw 2.0
set style line 5 lt 5 lc rgb "black" lw 2.0
##############################
f(x)=a+b*x
fit [120:225] f(x) 'diff-xy-maltoLyo12per.dat' via a,b
plot 'diff-xy-maltoLyo12per.dat' using 1:2 with lines linestyle 1 title "{/Symbol b}Mal-C_{12}", f(x) lw 3.0 lc rgb 'black'
Here I plot the fitting graph from 1 to 120 as shown . Also I want to plot the same graph from range 120 to 225 as in the picture .
Now I want a single plot which contain the two black lines and the red line.
How can I achieve this?
Thanks in advance.
Working with the script you already have, you can use two functions to fit in the different ranges separately, and then use a conditional plot that selects one if x < 120 and the other one if x > 120:
f1(x)=a1+b1*x
fit [0:120] f1(x) 'diff-xy-maltoLyo12per.dat' via a1,b1
f2(x)=a2+b2*x
fit [120:225] f2(x) 'diff-xy-maltoLyo12per.dat' via a2,b2
f(x) = x < 120 ? f1(x) : f2(x)
plot 'diff-xy-maltoLyo12per.dat' using 1:2 with lines linestyle 1 title "{/Symbol b}Mal-C_{12}", f(x) lw 3.0 lc rgb 'black'
Now, the way I would go about this, would be to generate a special fitting function, whose parameters would give me the point at which the slope changes as a result of the fitting itself. Say you call that point x0 (for which the value of the function is y0), the slope at the left of it is m1 and the slope at the right m2. Then the function at the left has the form m1*(x-x0)+y0 and the function at the right has the form m2*(x-x0)+y0. The overall function can be defined in gnuplot as:
f(x) = x < x0 ? m1*(x-x0)+y0 : m2*(x-x0)+y0
and you can fit f(x) "data" via x0, m1, m2, y0. You can also generate this function without the condition using a step function:
f(x) = m1*(x-x0)*(sgn(x0-x)+1)/2 + m2*(x-x0)*(sgn(x-x0)+1)/2 + y0
After you fit, for which you might need to provide some initial values, you can print x0 and you'll get the best value (that should be close to 120 in your case, as you know) for the position of the change in slope.
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.
With the following simple data file
1 1
2 3
3 4
and this script
set style line 2 lt 3 lc rgb "red" lw 3
show style line
set xrange [0:5]
set yrange [0:5]
plot "test_data.txt" u 1:2 ls 1
I don't see the line. Instead I only see the points. More than that, I don't see (1 1). Why? I followed the same steps form here
You have a data file, the example you reference uses functions. In gnuplot you need to specify that you want to use lines (with lines or in short w l) if you want to join data points with lines. Also, I can see (1 1) on your graph. Also I noticed you defined style line 2 but then used ls 1 instead of ls 2 to plot your data (that is you're not using the style you previously defined). Try
plot "test_data.txt" u 1:2 w l ls 2
If you also want to see the points together with lines, then use with linespoints or w lp:
plot "test_data.txt" u 1:2 w lp ls 2