I have to say that i am new to Gnuplot.
I have a file with 3 columns of datas and I managed plotting it with
gnuplot "name.txt" obtaining a 3D graph. Now i would want to graph n lines of that txt each second. I read that it is possible if the file update itself each second but it is not my case.
I have this file with datas that are calculated by a c++ program and represent the position of an object every second . Is it possible to live update the Graph so that you can see n points plotted each second ?
Until now I managed to do this byte Command : splot "data.txt" every ::1::10 . With this Gnuplot draw n lines form data.txt
Here is one possibility:
do for [N=10:*:10] {
splot 'name.txt' every 1::1::N using 1:2:3 with points
pause 1.0
}
Related
I have a 2D plot and want to draw horizontal straight lines from a given data file, so that each data point of the file is represented as a horizontal straight line in the existing 2D plot.
My approach so far:
I've tried using the for command, but I don't know how to write the current data point into a formular like x = C where C is the value of the data point:
for [i=1:10] "data.dat" u 2 every ::i::i
... is not what I meant.
for [i=1:10] x = "data.dat" u 2 every ::i::i
... is not a valid gnuplot command.
And furthermore, the range of i is variable, so that is another problem I have to solve with this approach.
Using arrows:
Like this posts suggests: Adding Horizontal lines on 2D plot with gnuplot. But in that example the author didn't need to draw the lines from a data file.
Is there a good way to do this?
I want to draw lines from origin (0,0) to all points whose coordinates are given in a file, using gnuplot. For e.g. if the file contains data as:
1,1
1,2
Then I want a straight lines from (0,0) to (1,1) and (0,0) to (1,2). Since I have a lot of points, I can't do it manually for each point in the file. How to accomplish this ?
One simple way to accomplish this would be to plot using vectors, but setting the origin as (0,0) for all points, then removing the vector heads:
plot "datafile" using (0):(0):1:2 with vectors
which results in:
More info here. by the way, if your input files looks exactly like the one you posted:
1,1
1,2
You'll need to add set datafile separator ',' before plotting. Hope it helps!
A possible way is to use a plot for loop over the block index. If you insert two white lines between the coordinates in your file, they are viewed as different blocks, so that you can write
plot for [j=0:N] 'data.dat' index j u 1:2 with lines
where N is the number of points. However, in this way you need to add the point of the origin in your file in each block, i.e. in the form
#your data file
0 0
1 1
0 0
1 2
I don't know how many points you have or if you have to perform this on many files. With few points you could modify the file by hand, otherwise I will suggest preparing a script (in bash for example with sed or others...).
I have a file with 1200 rows. I am trying to use every command which will plot any chunk of data (for example from 6th to 800th data but every 5 points. I know how to exploit every to select first 1000 data (but not any chunk) and every 5 points separately. Is there any way to do that in an one liner?
Plot "file.dat" every ::::1000 every 5 u 1:4 fails to do that. Thanks!
See help every for an explanation of the empty sites in your every ::::1000 command:
Syntax:
plot 'file' every {<point_incr>}
{:{<block_incr>}
{:{<start_point>}
{:{<start_block>}
{:{<end_point>}
{:<end_block>}}}}}
In your case you need only the point parameters, block marks distinct parts of a data file which are separated by one newline.
So you plot command to select every 5th point between the 6th and 800th row is:
plot 'datafile.dat' every 5::6::800 using 1:4
If what you want is to plot every fifth point from only the first 1000 points, I do not think there is a (reasonably simple) way to do that in pure gnuplot. One option is to use an external command to do simple processing on your data file:
plot '< head -n 1000 datafile.dat' every 5
(For details on what that syntax does, type help plot special in gnuplot, or search for 'popen' in the gnuplot docs.)
I have a data file that lists hits and misses for a certain cache system. Following is the data file format
time hits misses
1 12 2
2 34 8
3 67 13
...
To plot a 2D graph in GNUPlot for time vs hits, the command would be:
plot "data.dat" using 1:2 using lines
Now I want to plot a graph of time vs hit-ratio, For this can I do some computation for the second column like :
plot "data.dat" using 1:2/ (2 + 3) using lines
Here 1, 2, 3 represent the column number.
Any reference to these kind of graph plotting will also be appreciated.
Thanks in advance.
What you have is almost correct. You need to use $ symbols to indicate the column in the calculation:
plot "data.dat" using 1:($2/($2 + $3))
Since you are using $n to refer to the column numbers, you now are able to use n to refer to the number itself. For example,
plot "data.dat" using 1:(2 * $2)
will double the value in the second column.
In general, you can even plot C functions like log and cos of a given column. For example:
plot "data.dat" u 1:(exp($2))
Note the parens on the outside of the argument that uses the value of a particular column.
See here for more info.
I have a table like this:
A B C D E F G H I
10 23998 16755 27656 17659 19708 20328 19377 18925
20 37298 33368 53936 41421 44548 40756 40985 37294
I use this command to plot
plot "C:/file.txt" using 1:2 with lines smooth bezier, "C:/file.txt" using 1:3 with lines smooth bezier, ...
However, all the labels come out as the file name. Is it possible for gnuplot to read the first row and label the lines accordingly?
set key autotitle columnhead
plot for [n=2:12] 'vv.csv' u 1:(column(n)) w lines title columnhead(n)
n starts from 2 to skip the header.
I checked the documentation and I don't see a way to do it automatically, but you can manually set a title with
plot "file.txt" using 1:2 title "A" with lines smooth bezier ...
I once wrote a script to plot FM radio station frequencies along an axis from 87MHz to 108MHz, using the names of each radio station as vertical labels. This was not a pure gnuplot solution, the input file is processed with perl with make, but I suggest you have a look at it and see if you can use something like that.
You could also use a gnuplot toolkit such as this one for Python if you want have a lot of data to plot and you want to automate the extraction of the titles.