adding a condition to blkproc()

I use the following code to find the mean value of non-zero values of each block of an array. I wonder how I can add a condition to have a mean value if the number of non-zero values are bigger than 75% of the size of the block. I apperciate your help.

   mean_wout_zeros = blkproc(Myarray,[block block],@(x)sum(x(:))./(sum(logical(x(:)))));

Answer 1

[Sean de Wolski]

Just use this as your function

function out = meanZ75(in)
%mean sans zeros if there are 25% or more zeros
%pure mean if there are < 25% zeros
%SCd 07/11/2011
%

    in = in(:);
    if nnz(in) >= 0.25*length(in);
        out = mean(in(~~in));
    else
        out = mean(in);
    end

[Hassan]

Hi Sean, thanks for the comment. I dont know how to do that. could you please tell me in an example?

[Ashish Uthama]

Hassan, use meanZ75 as the input function handle: meanOut = blkproc(Myarray, [b b], @meanZ75);

[Hassan]

Thanks Sean for the code but I dont know how to use it. Should it be like as follows? what is 'in'?

mean_wout_zeros = blkproc(new_array2(:,:,i),[win_m win_m],@(x)sum(x(:))./(sum(logical(x(:)))));

function out = meanZ75(in)

%mean sans zeros if there are 25% or more zeros

%pure mean if there are < 25% zeros

%SCd 07/11/2011

%

in = in(:);

if nnz(in) >= 0.25*length(in);

out = mean(in(~~in));

else

out = mean(in);

end

[Sean de Wolski]

save

function out = meanZ75 etc.

to 'meanZ75.m' in your MATLAB folder in your documents. Then use it as the function for blkproc

blkoproc(new_array2(:,:,iu),[10 10],'meanZ75');