Dinesh Kumar Kala Sekar <contactdineshraji@gmail.com> wrote in message <1618512900.5126.1277497562574.JavaMail.root@gallium.mathforum.org>...
> Hi all, can anybody help me how to plot a 3d surface graph in which x axis for frequency range, y axis for ratio of two variables say Ri/Re and z axis plotted according to the formula
>
> omega=2*pi*f;
> r = 1./(1i.*omega.*c);
> z =abs(1/(1/Re + 1/( r + Ri)));
>
> here variable c is constant say 10.
> the problem is Re and Ri should not be declared as whole value to calculate ratio between them. instead as,
>
> if Ri = Re then value of Ri/Re is 1 this value should be at the mid point of y axis.
>
> if Ri > Re then value of Ri/Re is greater than 1 this value should be at the right side from the mid point of y axis upto certain range say, till Ri/Re = 10.
>
> if Ri < Re then value of Ri/Re is less than 1 this value should be at the left side from the mid point of y axis upto certain range say, till Ri/Re = 0.1.
>
> please help me out if anybody knows how to solve this. it would be helpful to carry forward my project work.
          
I think you need to explain your problem with greater care and detail. As it stands, it would appear to be impossible to uniquely determine the z coordinate, knowing only the ratio Ri/Re and frequency f. That is, for a given value of Ri/Re and f, there is an infinitude of possible values for z depending on the individual values of Ri and Re with that ratio.
To give you a concrete example of what I am saying, suppose that r = 3 and Ri/Re = 2. I say z is not uniquely determined. Let Ri = 2 and Re = 1 and we get z = 5/6. Yet if Ri = 4 and Re = 2, which has the same ratio, then z = 14/9. z is therefore not uniquely determined by Ri/Re and r, and there is no way to make the surface plot you are asking for. z could be any of infinitely many values for the same ratio Ri/Re.
Note: I realize that your r is pure imaginary, but the above statement of nonuniqueness still holds true nevertheless.
Roger Stafford
