How to find the mean of 12 different 3-D arrays containing nan so that I can omitnan in the final calculations?

I have 12 different 3-D arrays, say A, B, C, D, E, F, G, H, I, J, K, L, each of them having the dimension of 60x57x372. All of them contain several NaN values. I want to calculate the mean of these arrays to get an array of same dimension, that is of 60x57x372. How to do that?

Answer 1

[madhan ravi]

Use mean() with "Omitnan" flag

help mean

 MEAN   Average or mean value.
    S = MEAN(X) is the mean value of the elements in X if X is a vector. 
    For matrices, S is a row vector containing the mean value of each 
    column. 
    For N-D arrays, S is the mean value of the elements along the first 
    array dimension whose size does not equal 1.
 
    MEAN(X,'all') is the mean of all elements in X.
 
    MEAN(X,DIM) takes the mean along the dimension DIM of X.
 
    MEAN(X,VECDIM) operates on the dimensions specified in the vector 
    VECDIM. For example, MEAN(X,[1 2]) operates on the elements contained
    in the first and second dimensions of X.
 
    S = MEAN(...,OUTTYPE) specifies the type in which the mean is performed, 
    and the type of S. Available options are:
 
    'double'    -  S has class double for any input X
    'native'    -  S has the same class as X
    'default'   -  If X is floating point, that is double or single,
                   S has the same class as X. If X is not floating point, 
                   S has class double.
 
    S = MEAN(...,NANFLAG) specifies how NaN (Not-A-Number) values are 
    treated. The default is 'includenan':
 
    'includenan' - the mean of a vector containing NaN values is also NaN.
    'omitnan'    - the mean of a vector containing NaN values is the mean 
                   of all its non-NaN elements. If all elements are NaN,
                   the result is NaN.
 
    Example:
        X = [1 2 3; 3 3 6; 4 6 8; 4 7 7]
        mean(X,1)
        mean(X,2)
 
    Class support for input X:
       float: double, single
       integer: uint8, int8, uint16, int16, uint32,
                int32, uint64, int64
 
    See also MEDIAN, STD, MIN, MAX, VAR, COV, MODE.

    Documentation for mean
       doc mean

    Other functions named mean

       codistributed/mean    duration/mean    tall/mean
       datetime/mean         fints/mean       timeseries/mean
       dlarray/mean          gpuArray/mean

[Abhishek Chakraborty]

I tried that but the mean function on MATLAB works for one array only. I tried from another answer too (https://in.mathworks.com/matlabcentral/answers/88976-how-can-i-average-multiple-matrices-by-element-to-create-a-new-matrix-of-the-same-size) but unfortunately the matrices I have have scattered NaNs and hence summing them up will not result in the correct answer.

[madhan ravi]

Concatenate those 12 matrices along the 4th dimension and mean() it along the 4th dimension with "omitnan" flag.

[Abhishek Chakraborty]

Thanks. I got the answer.

Concatenate=cat(4,A,B,C,D,E,F,G,H,I,J,K,L);
MEANALL=mean(Concatenate,4,'omitnan');