Error wiritting an expression

Hi,

I have an error expression when I write the expression below:

 Z=(0.5176*(116*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))-0.4*Y-5)*exp((-21)*((1./(X+0.08*Y))-(0.035./(Y.^3+1))))+0.0068*X)

So to look for the error, I write the first expression which is :

 A=0.5176*(116*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))-0.4*Y-5)

and I simulate it and it works

the same thing for the second expression, when I simulate it it works :

B=(exp((-21)*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))))+0.0068*X

The problem is that the expression Z is equal to A*B and when I simulate it, it generates an error expression

[KSSV]

Post the full code....you have to read about element by element matrix operations.

[Hicham Lhachimi]

In the code try to simulate the two expression that are commented to see that they are working.

Here is the code :

x=0:1:20

y=0:2:20

[X, Y]=meshgrid(x,y)

_% Z=0.5176*(116*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))-0.4*Y-5)_

_% Z=(exp((-21)*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))))+0.0068*X_

Z=0.5176*(116*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))-0.4*Y-5)*(exp((-21)*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))))+0.0068*X

mesh(X,Y,Z)

Answer 1

[Star Strider]

You have used element-wise calculations in your code except for the multiplication between the terms:

Z = A .* B

If ‘A’ and ‘B’ work independently, then that should make them work in ‘Z’ as well.

----------------------------

EDIT —

x=0:1:20;
y=0:2:20;
[X, Y]=meshgrid(x,y);

Z=0.5176*(116*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))-0.4*Y-5).*(exp((-21)*((1./(X+0.08*Y))-(0.035./(Y.^3+1)))))+0.0068*X;
→          →          →          →          →           → ↑ DO ELEMENT-WISE MULTIPLICATION HERE
figure(1)
mesh(X,Y,Z)
grid on