I create a study with multiple general form PDEs. When I attempted to define variables under Definitions, some variable is actually a function of space coordinate x. For example, eps = omega*x. Upon Compute, an error occurs saying Undefined variable x and all variables depending on x become invalid. x is clearly a default space coordinate name. Why is there such error?
Note: In the attached file, I changed the argument for "sp" function to t since the t-array is given. The "sp" function is to somehow make "x" valid/defined. If only I could call the mesh-array value like that and use as "x" values.