gnuplot (1)

# Launch interactive shell.
gnuplot

# Launch interactive shell.
gnuplot [opt]
  opt:
    -p ................ persist plot window
    -c <file> ......... run script file
    -e "<cmd1>; .." ... run cmd(s)

Frequently used configuration

# Plot title.
set title "the plot"

# Labels.
set xlabel "abc"
set ylabel "def"

# Output format, 'help set term' for all output formats.
set term svg
# Output file.
set output "out.svg"

# Make axis logarithmic to given base.
set logscale x 2

# Change separator, default is whitespace.
set datafile separator ","

Plot

# With specific style (eg lines, linespoint, boxes, steps, impulses, ..).
plot "<data_file>" with <plot_style>

> cat data.txt
1 1 3
2 2 2
3 3 1
4 2 2

# Plot specific column.
plot "data.txt" using 1:2, "data.txt" using 1:3
# Equivalent using the special file "", which re-uses the previous input file.
plot "data.txt" using 1:2, "" using 1:3

# Plot piped data.
plot "< head -n2 data.txt"

# Plot with alternate title.
plot "data.txt" title "moose"

Example: multiple data sets in plot

# file: mem_lat.plot

set title  "memory latency (different strides)"
set xlabel "array in KB"
set ylabel "cycles / access"

set logscale x 2

plot "stride_32.txt"  title "32"  with linespoints, \
     "stride_64.txt"  title "64"  with linespoints, \
     "stride_128.txt" title "128" with linespoints, \
     "stride_256.txt" title "256" with linespoints, \
     "stride_512.txt" title "512" with linespoints

On Linux x86_64, mem_lat.c provides an example which can be run as follows.

gcc -o mem_lat mem_lat.c -g -O3 -Wall -Werror

for stride in 32 64 128 256 512; do \
    taskset -c 1 ./mem_lat 128 $stride | tee stride_$stride.txt ; \
done

gnuplot -p -c mem_lat.plot