The solution is to use NaN value, which states for Not a Number
and is not displayed in the waveform graph.
If you insert into your array of numeric data NaN values, this part of a plot will be not shown on the graph.
An example of a simple implementation of a mentioned idea is given below.
Each array of numeric values has a corresponding array of LEDs. State of the LED decides, if the specific element of the array should be displayed on the graph. If the LED is on, data are normally shown on a graph. If LED is off, NaN value is passed to the graph and it is not displayed.