Need help with 1/ matrix in problem

I have an equation that must be solved that keeps throwing the error "Error using /

Matrix dimensions must agree."

The code I have is

% Finding Delt H
syms dh
 eqn2=log(p_rng)== (dh/R)*(1/t_rng)
 for i=1:300
     D_h(i,:)=double(vpa(solve(eqn2(i),dh)));
 end

It seems as though 1/t_rng is what causes the error. When changed to just t_rng the error no longer occures

[madhan ravi]

size(p_rng)
size(t_rng) % ?

Do you realise there is only one eqn2 but then you run a loop through it ? Probably you meant to run a loop through variable elements of t_rng and p_rng ? Beware D_h isn’t preallocated.

Answer 1

[Kevin Phung]

you're going to need the dot operator (.) for element-wise operations.

Probably something like this:

syms dh
 eqn2=log(p_rng)== (dh./R).*(1./t_rng)
 for i=1:300
     D_h(i,:)=double(vpa(solve(eqn2(i),dh)));
 end

[Stephen23]

Read this to know the differences between array and matrix operations:

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html