How can I take a mean of a matrix only from 10 first rows?

I have a 50000x3 matrix X and I would need to take column means taking only first 5000 rows into account.

mean_values = mean(X(1:5000, :)) only gives one mean value instead of giving mean values for each 3 columns.

What should I do?

[Stephan]

which release do you use?

[James Tursa]

Did you inadvertently shadow the mean( ) function?

[Marianne Auvinen]

I'm using R2018b

Answer 1

[madhan ravi]

>> X = rand(50000,3); % are you sure it's a 50000 by 3 matrix?
>> mean(X(1:5000,:))

ans =

    0.5028    0.5015    0.4978

>> 

[Marianne Auvinen]

Thanks I found the problem. It wasn't 50000x3 after all