insertNaN

usage: output=insertNaN(data,threshold);
INPUTS: data - vector/matrix data which will be checked for gaps
threshold - threshold value to distinguish where NaN's are placed in the data
OUTPUTS: output - input data, with NaN values inserted where differences exceeded the requested threshold

Example 1:
output=insertNaN([11:13 15:17 19:21 25:27],1);
returns:
output = [11 12 13 NaN 15 16 17 NaN 19 20 21 NaN 25 26 27]

Example 2:
output=insertNaN([[1:2 5:7 9:10].',[1:7].',[11:17].'],1);
returns:
output =
1 1 11
2 2 12
NaN NaN NaN
5 3 13
6 4 14
7 5 15
NaN NaN NaN
9 6 16
10 7 17

Useful to denote "pen up" breakpoints when generating plots or maps where gaps occur in timeseries, position data, etc.