How do I insert variables into a matrix???

I'm a beginner at matlab and cannot figure out how to insert variables into a matrix. In my circuits class, I'm trying to find the voltage in terms of the many resistors, which I want to call r1 r2 r3 ..... When I put these variables into my matrix I get this error message "The following error occurred converting from sym to double;Double cannot convert the input expression into a double array. If the input expression contains a symbolic variable, use VPA." I've been trying to find answers on youtube or here, but I haven't found something that works. Any tips? Thank you

Answer 1

[Walter Roberson]

You initialized your matrix numerically, such as

ABC = zeros(5,11);

You need to initialize your matrix symbolically, such as

ABC = sym(zeros(5,11));

[Tarou Seki]

Thank you very much. I got it to work. This saves so much time.