How to get the mean of a vector ?

Trying to get the average of the 4 values in contrast by M=mean(cbr.contrast); and it's not working,also tried M= mean(cbr) didnn't work either and it's giving the following error Undefined function 'sum' for input arguments of type 'struct'.

Error in mean (line 115) y = sum(x, dim, flag)/size(x,dim);

Answer 1

[dpb]

   M=mean(cbr.contrast);

Field names are case sensitive in Matlab; it's .Contrast'

NB: capitalization in the table of property names in the doc.

PS: If you just type the structure name at command line it will echo the field names and content summary that will also let you see the spelling and what they are. Or

fieldnames(theStructVariable)

returns them as cellstr array