Problem 320. Maintain shape of logical-index mask

Created by the cyclist in Community

When using logical indexing into an array, MATLAB returns a vector output. For example, if

A = magic(3);
mask = logical([0 1 1; 0 1 1; 0 1 1]);



returns the output

out =

But when the mask has a block format (as in this example), it is sometimes desirable to maintain that block shape in the output. So, in this case, the desired output would be

out =
       1   6
       5   7
       9   2

In other words, the output is the same shape as the logical index block.

The (first) input array A will be two-dimensional, and the (second) input array mask will be a logical that is guaranteed to have the block characteristic.

Solution Stats

41.27% Correct | 58.73% Incorrect
Last solution submitted on Jan 22, 2019

Problem Comments

Recent Solvers53

Suggested Problems

More from this Author23

Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

MATLAB Academy

New to MATLAB?

Learn MATLAB today!