How to find the length of segments of a matrix that meet certain condition?

Hi guys, I am trying hard to think of an algorithm for this, but no luck.

If I have a matrix a = [77 77 77 79 79 79 77 77 77 77];

And I want to find the length of segments that are equal to 77 (3 and 4).

What is the most efficient way to do this?

thank you very much for your help!

[per isakson]

See % RUNLENGTH_M - RLE coding as M-function for education

You find RUNLENGTH_M under the Functions tab.

Answer 1

[Image Analyst]

Simply use the function meant for that. If you have the Image Processing Toolbox, use regionprops:

a = [77 77 77 79 79 79 77 77 77 77];
props = regionprops(a == 77, 'Area');
allLengths = [props.Area]

You'll get:

allLengths =
   3     4