How can I get the standard error of each row of a matrix?

Hello,

I have a 8x30 matrix 'data' and need the mean and standard error of each row. I've figured out the mean

mean_data=mean(data(1:8,:))

but I have no idea about the standard error. I have tried to get the std of the mean, but no matter what I do I just jet the std of the whole matrix, not each row. I've tried for example:

std_mean=std(mean_data,[],2)

or

std_mean=std(mean(data(1:8,:)))

I'm probably really stupid, but I've just started Matlab two weks ago and fail at the easiest things....help would be appreciated!

[hxen]

Not stupid. We all start out struggling learning at first.

Answer 1

[Star Strider]

The standard error of the mean (link) is defined as the standard deviation divided by the square root of the number of samples:

std_err_mean = std(data,[],2)/sqrt(size(data,2));                   % Standard Error Of The Mean (Row-Wise)

To calculate the 95% confidence intervals, continue with:

mean_data = mean(data,2);                                           % Mean (Row-Wise)
P95 = tinv(0.975, size(data,2)-1);                                  % Compute 95% Confidence Standard Deviation
CI95 = mean(data,2) + std_err_mean*[-1 1]*P95;                      % 95% Confidence Intervals (Row-Wise)

[hxen]

You're a very helpful person Star and very much appreciated. Many of you great people on this community have been super helpful.