how to check if two arrays intersect within a matrix?

i have a 10x10 matrix of zeros.

three ships called destroyer,aircraft_carrier and cruiser:

destroyer=[2,2] %placed either vertically or horizontally within the matrix

cruiser=[4,4,4,4]%placed either vertically or horizontally within the matrix

aircraft_carrier=[5,5,5,5,5] %placed either vertically or horizontally within the matrix

i wrote the code so that the ships are placed randomly and also in a random alignment,vertical or horizontal.i want to check weather they intersect with each other so i can write code to prevent it.

i tried using intersect(a,b) command but it gave me back an empty matrix even when the point where intersecting..i dont know what i am doing wrong or if there is some other command to help me do this.....

Answer 1

[Image Analyst]

Try this:

blankElements = (matrix1 == 0) & (matrix2 == 0);
matrixIntersections = (matrix1 ~= matrix2) & ~blankElements;

[roshan varkey]

WHAT DOES THIS DO?

[Image Analyst]

If you have two 10x10 matrices and you've go a line of 4's in one matrix and a line of 5's in the other matrix, the first line determines where they are both zeros.

Then the (matrix1 ~= matrix2) finds out where they don't match. They won't match as points there the line of 5's crosses the line of 4's. But they also don't match where you have a 5 in one matrix and a 0 in the other matrix, and you don't want to count that as an intersection, so I AND it with the blank (0) elements to erase the non-matches in that situation.

[Image Analyst]

roshan's 'Answer' moved here:

Brilliant! thank you very much!

[Image Analyst]

OK, if we're done, then please go ahead and mark it Accepted.