Mean of parts of an array

Good day to all,

I have searched for an answer can't seem to find it so here goes my description.

I have an array called MeanOfSegments which is 152x1 double (see figure)

I wish to take the mean of parts of this array. This worked great for my first few variables which were consecutive. Here is the successful code I used

if true
  % code
MeanVariable1 = mean(MeanOfSegments(1:7));
end

Now I wish to create a variable called MeanVariable2 which is the mean of cell 8,12,13,17. I have tried the following code with no success.

if true
  % code
MeanVariable2 = mean(MeanOfSegments(8,12,13,17));
end

Does anyone know how this can be obtained? I am using R2014a

Thanks for any and all help. Andrew

Answer 1

[Adam]

Try putting your 8, 12, 13, 17 in square brackets as

MeanVariable2 = mean(MeanOfSegments( [8,12,13,17] ));

Answer 2

[Andrew]

Well that was ridiculously easy. Thank you very much for your answer. I'm new to MatLab syntax. Thank you very very much.

[Adam]

That syntax just means that all your indices are in an array so they can then be used for non-contiguous indexing.

Passing 4 comma delimited numbers in as they are would be interpreted by Matlab as though you are trying to index into a 4-dimensional matrix.

I get used to many of these things just by trying out syntaxes on the command line so you can pick things up quite quickly like that!