picking maximum difference across entries of row vectors, Part 3

Question

alpedhuez 2018-6-6

回答： Kaushik Lakshminarasimhan 2018-6-7

The question is

for each row, take a difference between every possible pair of two elements in the row and returns the maximum difference

Now A can have missing values. For example, A =[ NaN NaN 3 9 4]. In this case the previous solution

vec = sort(A);
B = vec(end)-vec(1);

does not return a correct answer 6. Please advise.

alpedhuez 2018-6-6

Suppose I replace NaN by -infty. Then the problem would be about taking the difference between max and min among nonzero elements for each row.

alpedhuez 2018-6-7

编辑：alpedhuez 2018-6-7

I can run a loop for each row calculates

max(D(i,:),[],'omitnan')-min(D(i,:),[],'omitnan');

but would hope simpler code.

Answer 1

A = [NaN NaN 3 9 4 ; 1 100 NaN 34 12];
maxdiffs = max(sort(A,2),[],2) - min(sort(A,2),[],2);