Mupad error, gui, handle function

My question is simple

It is a programme about fluid kinematics, ux is edit text, refers ug(handles,x,y) vx, refers vg(handles,x,y)

My wish is to get the velocity acceleration and streamlines file like that, and to calculate the results in spesific x and y, for example at(2,3) ui=x.^2=4; vj=9

When it plots the graph it uses matrice between -5 5 in x coordinate and -5 5 in y coordinate, and it quivers the ux=x.^2 and vx=y.^2 to 5x5 matrix

but when i attempt to evaluate x.^2 at x= 2 it gives Mupad error

"Error using sym>convertExpression (line 1391)

Conversion to 'sym' returned the MuPAD error: Error: Invalid input. 'expression' is

expected. [line 1, col 23]"

When i convert x.^2 to x^2 it evaluate to 4 but the matrix value wrong.

So, my question is simple. I should use x.^2 for graph, ı should use x^2 for equation. is there any way to get this.

Can we convert x.^2 to x^2? or x^2 to x.^2 ı should use it two of them same time.