MATLAB: Data gap finding in a time sires

gap finding

Hello,
The attached file has two columns, time and levels. It has 6 missing data gaps. I want to find the index of each gap like this;
gap1 index 7-13
gap2 index 38-42
gap3 index 67-81
gap4 index 108-111
gap5 index 141-151
gap6 index 182-184
Your help is highly appreciated.
Thank you
Dash

Best Answer

Compute start and stop indices for NaN segments in height variable (column vector). 
nanStartIdx = find(diff(isnan([0;height;0]))==1);
nanStopIdx = find(diff(isnan([0;height;0]))==-1);
Show the results. 
% Show index of NaN values
ax = cla(); 
plot(isnan(height), '-k', 'LineWidth', 2)
ylim([-.2, 1.5])
xlabel('index')
ylabel('is NaN')
set(ax, 'YTick', [0,1], 'YTickLabel', {'False', 'True'})
hold on
arrayfun(@(start)xline(start, 'b-','Start'), nanStartIdx)
arrayfun(@(stop)xline(stop, 'c-','Stop'), nanStopIdx)
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