June 9th, 2010 | 11 Comments

If you have measurement data and like to plot them as points combined by lines, you will probably do that with the `linespoints`

plotting style. But for some applications it is required to combine the data points by non-continuous lines to emphasize that the data came from measurements as shown in Fig. 1.

In Gnuplot exists no line style that can do this directly. But with a little trick it is very easy to achieve. Since Gnuplot 4.4. there exists the property `pointinterval`

(see the documentation) in combination with the plotting style ` linespoints`

. This property plots not every single point, but only every second for a value of `2`

and so on. But if we use the value `-1`

it tells Gnuplot to insert a little gap between the points and the line. The size of the gap can be set by the `pointintervalbox`

property.

set style line 1 lc rgb '#0060ad' lt 1 lw 2 pt 7 pi -1 ps 1.5 set pointintervalbox 3

We specify a point interval `pi`

of -1 and a point size of 1.5, in addition we set the the gap to a point size of 3. Now we can plot our data with the `linespoints`

style.

plot 'plotting_data1.dat' with linespoints ls 1

Using the same data as in the first plot of the gnuplot basics tutorial Plotting data we will get Fig. 1 as a result.