chriswolfvision
How to use time data as input?
How can I tell eplot that my first column contains timestamps?
I have tried this:
echo '2022-12-15T12:18:26 104.8
2022-12-16T12:36:16 81.36
2022-12-17T14:06:25 79.875' | eplot -d -x 'xdata time; timefmt "%Y-%m-%dT%H:%M:%S"'
and
echo '2022-12-15T12:18:26 104.8
2022-12-16T12:36:16 81.36
2022-12-17T14:06:25 79.875' | eplot -d -x 'xdata time' -x 'timefmt "%Y-%m-%dT%H:%M:%S"'
(and without -x).
But it's still wrong.
(Sorry if my approach is completely wrong. I don't have experience with gnuplot. I just found eplot and thought it would be great if it's really that easy!)
This is the corresponding gnuplot script:
set terminal dumb
set xdata time
set timefmt "%Y-%m-%dT%H:%M:%S"
set grid
plot 'data.txt' using 1:2 with lines
EDIT: Simplify tested eplot commands. Add working gnuplot script.
After looking into the code, I have doubts that x-axis options are supported at all.
The README says -x is for the label and other options:
-x x-options (e.g. -x 'sigma') Change options of the x-axis, e.g. the label but also other options.
The help looks like -x is for x-axis options in general:
-x <x-axis-opt> provide x-axis options
But in the code, it looks like it's only about the label:
# ---- the x-axis label
when /^-x$|^--xlabel$/
com=com+"set xlabel \""+checkOptArg(xargv,i)+"\";\n"
i=i+1
I'll try to provide a pull request for this.
I can "inject" additional settings like this:
echo '2022-12-15T12:18:26 104.8
2022-12-16T12:36:16 81.36
2022-12-17T14:06:25 79.875' | eplot -d -x '";
set xdata time;
set timefmt "%Y-%m-%dT%H:%M:%S'
(See the unbalanced double quotes. This only works when you know how eplot handles the -x argument.)
But then gnuplot complains about the missing using spec:
echo '
set style line 1 lt 1 lw 1 pt 1 ps 0.5;
set style line 2 lt 3 lw 1 pt 1 ps 0.5;
set style line 3 lt 7 lw 1 pt 1 ps 0.5;
set style line 4 lt 4 lw 1 pt 4 ps 0.5;
set style line 5 lt 5 lw 1 pt 4 ps 0.5;
set style line 6 lt 2 lw 1 pt 2 ps 0.5;
set style line 7 lt 6 lw 1 pt 4 ps 0.5;
set style line 8 lt 8 lw 1 pt 4 ps 0.5;
set style line 20 lt 7 lw 1 pt 4 ps 0.5;
set terminal dumb;
set xlabel "";
set xdata time;
set timefmt "%Y-%m-%dT%H:%M:%S";
plot "/tmp/eplot20221218-119390-6bhk8e" with lines ls 1
'| gnuplot -persist
gnuplot> plot "/tmp/eplot20221218-119390-6bhk8e" with lines ls 1
^
line 0: Need full using spec for x time data
This can be fixed by:
diff --git a/eplot b/eplot
index 7e020ab..1497edb 100755
--- a/eplot
+++ b/eplot
@@ -437,6 +437,7 @@ class Controller
def runSinFrSin(filename)
styleArr=@oc["StyleIndices"].split(",")
com="\""+filename+"\" "
+ com=com+"using 1:2 "
com=com+"title \""+@oc["TitleString"]+"\" " if @oc["TitleString"]!=""
com=com+"with "+@oc["LineType"]+" ls "+styleArr[0]
plot(com,false)
But this might break other use cases. I think such a change should be done only by someone who knows about its consequences.