Logical Indexing Within a Symbolic Array

Suppose I have a symbolic array like

A = [0 0 0 w7 0 0;

0 0 0 0 w9 0;

0 w3 0 0 0 0;

0 0 w5 0 0 0;

w1 0 w6 w8 0 0;

w2 w4 0 0 w10 0];

where w1, ..., w10 are symbolic real variables. I would like to generate a "binary" array which identifies where the symbolic variables w1, ..., w10 are located, meaning that the output should be

A_bin = [0 0 0 1 0 0;

0 0 0 0 1 0;

0 1 0 0 0 0;

0 0 1 0 0 0;

1 0 1 1 0 0;

1 1 0 0 1 0];

Is there a way MATLAB could generate A_bin from A?

Thank you.

Answer 1

[Ameer Hamza]

Try this

syms w1 w2 w3 w4 w5 w6 w7 w8 w9 w10

A = [0 0 0 w7 0 0;
     0 0 0 0 w9 0;
     0 w3 0 0 0 0;
     0 0 w5 0 0 0;
     w1 0 w6 w8 0 0;
     w2 w4 0 0 w10 0];
A_bin = ~isAlways(A==0)

or

A_bin = ~isnan(A./A)

[Kamal Premaratne]

Fantastic. Thank you so much.

[Ameer Hamza]

I am glad to be of help!

Answer 2

[Walter Roberson]

~isSymType(A, 'constant')

[Kamal Premaratne]

This also works. Thank you very much.