Error: A(:) = B, the number of elements in A and B must be the same.

Hi everyone, I can't seem to understand why this piece of code:

 while( empty_cond ~= 0 &&  myStack.peek()~= goal)  

        %pop first index from the stack
        i = myStack.pop();

        %if node at i has not been visited
        if ( visited(i) == 0) 

            %mark it as visited
            visited(i) = 1;

            neighbors(i) = sense_maze(i, data);

        end

I end up getting this error:

In an assignment A(:) = B, the number of elements in A and B must be the same.

Error in RUNME (line 55) neighbors(i) = sense_maze(i, data);

I also attached a picture of the workspace.

[Image Analyst]

How are we to know which line threw that error? You forgot to include the complete error, which includes the line number and line of code. Please include ALL THE RED TEXT.

[Ammar Babikir]

Oh sorry about that. i just edited my post. I included all the red text.

Answer 1

[Image Analyst]

Two problems. First, sense_maze does not show up in your workspace so the code does not know about it at that point. Secondly data is a structure, not an integer starting from 1. So you need to get the integer from the structure.

[Ammar Babikir]

Thank you for pointing that out. That's very strange because I have a sense_maze.m file in the same folder as my RUNME file.

Also, what do you mean by "getting the integer from the structure?"

[Image Analyst]

OK, if sense_maze is a function in a separate m-file on the search path, then that is okay. However the error message is acting like sense_maze is an array. Please attach that m-file so I can see what kind of input is expected for its second argument.

data is a structure, not a number - this is what the error message is telling you. So it has fields, like a, b, and myNumber or whatever. Save data to an mat file and attach that also.

[Ammar Babikir]

I was able to figure it out. There was an issue with my indexing of neighbors and once I fixed that, my code worked fine.