Cody

Problem 1972. Convert matrix to 3D array of triangular matrices

Solution 1543150

Submitted on 29 May 2018 by Riccardo Dessì
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Test Suite

Test Status Code Input and Output
1   Pass
x = 1:100; y_correct = shiftdim(x,-1); assert(isequal(mat2triu3(x),y_correct))

2   Pass
x = reshape(1:15,3,[]); y_correct(:,:,1) = [1 2;0 3]; y_correct(:,:,2) = [4 5;0 6]; y_correct(:,:,3) = [7 8;0 9]; y_correct(:,:,4) = [10 11;0 12]; y_correct(:,:,5) = [13 14;0 15]; assert(isequal(mat2triu3(x),y_correct))

3   Pass
x = reshape(1:18,3,[])'; y_correct(:,:,1) = [1 4 10; 0 7 13; 0 0 16]; y_correct(:,:,2) = [2 5 11; 0 8 14; 0 0 17]; y_correct(:,:,3) = [3 6 12; 0 9 15; 0 0 18]; assert(isequal(mat2triu3(x),y_correct))

4   Pass
x = randi(50,sum(1:100),22); y = mat2triu3(x); mask = (y~=0); xb = reshape(y(mask),[],size(y,3)); assert(isequal(size(y),[100 100 22])) assert(isequal(x,xb))