gnuplot: change x-axis to start from specific numer - gnuplot

I have a file named 'data.txt':
25
76
90
100
120
135
And I want to make my plot x-axis looks like this:
0 4 8 12 16 20 24
I want to put first value from file to the plot on 4 position then next value to 8 position and so on. How can I do that?

similar questions have been asked here already, however, I can't recall what the titles were...
In gnuplot, check help pseudocolumns. $0 gives you the line number of the datafile, starting from 0. So, just multiply this with 4 and you'll have your added x-values.
plot "data.txt" u ($0*4):1 w lp pt 7 lc rgb "red"
Result:

Related

plotting single (datum,column) from each block with lines in gnuplot

I have a data file containing constant-size blocks of data. In order to plot element (n,m) from each block I do
pl file u m ev ::n-1::n-1
This works fine, but the graph is displayed in point style since this is default for data. When I add "with lines" to the command above, this produces an empty graph.
Maybe there are shorter solutions, but the first solution which comes to my mind is to plot the data into a datablock and then plot this datablock. This will remove empty lines and hence datapoints will be connected when plotting with lines or with linespoints.
Code:
### plot individual datapoints from each block with lines
reset session
$Data <<EOD
1 11
2 12
3 13
4 14
5 15
6 16
7 17
8 18
9 19
EOD
m = 2
n = 1
set table $DataSelected
plot $Data u m every ::n-1::n-1 w table
unset table
plot $DataSelected u 1 w linespoints pt 7
### end of code
Result:

gnuplot - how to plot invisible points so that the plot is only used to mark x-axis

I have the following data in data file test1.txt:
A 36 1
A 35 1
B 48 2
B 37 2
B 15 2
C 36 3
C 25 3
and test2.txt
A 16 1
A 25 1
B 38 2
B 45 2
C 36 3
the plotting is done as:
dat1="test1.txt"
dat2="test2.txt"
plot dat1 u ($3-0.2):2 w p t 'title 1', \
dat2 u ($3+0.2):2 w p t 'title 2', \
dat1 using 3:(0):xticlabels(1):x2ticlabels(1) notitle, \
dat2 using 3:(0):xticlabels(1):x2ticlabels(1) notitle
The whole point is to have the labels from the first column on the x axis. The issue is that the last two parts of plot
dat1 using 3:(0):xticlabels(1):x2ticlabels(1) notitle, \
dat2 using 3:(0):xticlabels(1):x2ticlabels(1) notitle
produce points at y=0. And because I cannot (or I do not know how to) use
plot dat1 u ($3-0.2):2:xticlabels(1) w p t 'title 1'
(since it plots the label at x coordinate $3-0.2 and not at $3, which i require), I am forced to do two more dummy plots, but they produce points and I do not know how to effectively avoid this other than shifting the outside of the range of the plot by e.g. dat1 using 3:(0):xticlabels(-1):x2ticlabels(-1) in the case of plotting only positive values. Is there any good way of solving this?
I don't really understand what you are trying to do with your data, however if you want to make the points over the x axis invisible you can set the line color to full transparency for the last two plots:
dat1 using 3:(0):xticlabels(1):x2ticlabels(1) linecolor "#FFFF0000" notitle, \
dat2 using 3:(0):xticlabels(1):x2ticlabels(1) linecolor "#FFFF0000" notitle
In recent versions of Gnuplot (link) it is possible to add transparency, in this particular case you want to set full transparency to the line color so that the points are invisible. The color format and transparency can be set using the hexadecimal notation #AARRGGBB where AA (alpha) controls how transparent the color is, for full transparency you want FF which is equivalent to 255, notice how my line color is RED but because is completely transparent we don't see it.
Plot with Full Transparency
My understanding of your question is the following: You have some data which you want to shift in x by +/-0.2 but the corresponding tic shouldn't be shifted.
You've been almost there. Of course, there are points at y=0 because you tell gnuplot to do so.
What you mean with "invisible" could of course be also achieved by fully transparent points, but the easier way is probably to "plot" the points at NaN, i.e. nowhere.
Code:
### plotting data with offset and tic without offset
reset session
set colorsequence classic
$Data1 <<EOD
A 36 1
A 35 1
B 48 2
B 37 2
B 15 2
C 36 3
C 25 3
EOD
$Data2 <<EOD
A 16 1
A 25 1
B 38 2
B 45 2
C 36 3
EOD
set offsets 0.5,0.5,0.5,0.5
set link x2
set x2tics
plot $Data1 u ($3-0.2):2 w p pt 7 t 'title 1', \
$Data2 u ($3+0.2):2 w p pt 7 t 'title 2', \
$Data1 using 3:(NaN):xtic(1):x2tic(1) notitle, \
$Data2 using 3:(NaN):xtic(1):x2tic(1) notitle
### end of code
Result:

plot 10 line sof 1000 values on gnuplot

I have a data file with 10 lines with 1000 values each line and I'm trying to plot this values with this script
#!/usr/bin/gnuplot -persist
plot "data.dat" using [1:1000] title "" with lines
but I get this error
plot "data.dat" using [1:1000] title "" with lines
^
"./plot.sh", line 3: invalid expression
How can I indiate a interval form the first value to the 1000 value?I't posible to set a diferent random clor to every line?
As #vaettchen pointed out, gnuplot wants data in columns and plotting rows is not straightforward. So, best would be if your data was transposed. Unfortunately, gnuplot has no function to transpose data. So, you have to use external tools to transpose your data.
Although, if your data is 10 lines with 1000 values each, i.e. a strict 10x1000 matrix, you could do something with gnuplot only (see below).
However, if your data is not a strict matrix, e.g. one line has more or less values or one value missing the method below won't work.
The following example (just 5 lines with 7 values each) illustrates plotting columns and plotting rows.
### plotting columns and rows
reset session
set colorsequence classic
$Data <<EOD
11 12 13 14 15 16 17
21 22 23 24 25 26 27
31 32 33 34 35 36 37
41 42 43 44 45 46 47
51 52 53 54 55 56 57
EOD
# get the number of rows
stats $Data u 0 nooutput
RowCount = STATS_records
# do the plot
set multiplot layout 1,2
set title "Plotting columns"
set xlabel "Row no."
set xtics 1
# plot all columns from 1 to *(=autodetection)
plot for [i=1:*] $Data u ($0+1):i w lp pt 7 not
set title "Plotting rows"
set xlabel "Column no."
# plot all rows
plot for [i=0:RowCount-1] $Data matrix u ($1+1):0 every :::i::i w lp pt 7 not
unset multiplot
### end of code
Which results in:

gnuplot : using a logarithmic axis for a histogram

I have a data file that I am creating a histogram from.
The data file is :
-0.1 0 0 JANE
1 1 1 BILL
2 2 1 BILL
1 3 1 BILL
6 4 0 JANE
35 5 0 JANE
9 6 1 BILL
4 7 1 BILL
24 8 1 BILL
28 9 1 BILL
9 10 0 JANE
16 11 1 BILL
4 12 0 JANE
45 13 1 BILL
My gnuplot script is :
file='test.txt'
binwidth=10
bin(x,width)=width*floor(x/width)
set boxwidth 1
plot file using (bin($1,binwidth)):(1.0) smooth freq with boxes, \
file using (1+(bin($2,binwidth))):(1.0) smooth freq with boxes
I would like to plot this data on a logscale in y. However there are some 0 values (because some of the bins are empty) that cannot be handled by set logscale y. I get the error Warning: empty y range [1:1], adjusting to [0.99:1.01].
According to gnuplot's help, "The frequency option makes the data monotonic in x; points with the same x-value are replaced by a single point having the summed y-values."
How can I take the log10() of the summed y-values computed by smooth freq with boxes?
There are at least two things that you could do. One is to use a linear axis between 0 and 1 and then use the logarithmic one as explained in this answer. The other one is to plot to a table first and then set the log scale ignoring the points with zero value.
With a normal linear axis and your code (plus set yrange [0:11]) your data looks:
Now lets plot to a table, then set the log scale, then plot ignoring the zero values:
file='test.txt'
binwidth=10
bin(x,width)=width*floor(x/width)
set table "data"
plot file using (bin($1,binwidth)):(1.0) smooth freq, \
file using (1+(bin($2,binwidth))):(1.0) smooth freq
unset table
set boxwidth 1
set logscale y
set yrange [0.1:11]
plot "data" index 0 using ($1):($2 == 0 ? 1/0 : $2) with boxes lc 1, \
"data" index 1 using ($1):($2 == 0 ? 1/0 : $2) with boxes lc 2
set table sometimes generates some undesirable points in the plot, which you can see at x = 0. To get rid of them you can use "< grep -v u data" instead of "data".

plot data at variable points using gnuplot

Here is my data file
seconds data
(x-axis ( y axis
points) points)
3.880000, 20
3.920000, 10
3.960000, 20
4.000000, 20
4.080000, 20
4.120000, 20
4.570000, 20
4.620000, 10
4.650000, 10
4.690000, 10
4.750000, 20
.
.
.
and so on
I want to plot points in column 2 at positions specified by column 1
ie I want 20 , 10 , 20 20, 20 etc to be present at 3.88 , 3.92, 3.96 on xaxis
Can anybody tell me how to do this ?
Suppose your data is in 1.txt:
plot "1.txt" using 1:2
I know it's been a long time, but for anyone else who stumbles upon this...
For this datafile, you'll also need a set datafile separator ','
e.g.
set datafile separator ','
plot 'data.dat' using 1:2
As a matter of style, it is probably best practice to explicitly comment out the header of the datafile using '#' characters. e.g.
# seconds data
# (x-axis ( y axis
# points) points)
3.880000, 20
3.920000, 10
3.960000, 20
4.000000, 20
4.080000, 20
4.120000, 20
4.570000, 20
4.620000, 10
4.650000, 10
4.690000, 10
4.750000, 20
For this simple example, it works without the comments, but other, more complicated datafiles may not.

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