## Why won't a function handle plot?

on 11 Sep 2012

### Matt Fig (view profile)

I have a long and complicated symbolic expression:
syms x
A=(60984*x)/(203125*exp((-(243936*x^4)/203125)^(1/4))*(-(243936*x^4)/203125)^(1/4)) + (((203125^(1/2)*19758816^(1/2)*(1/exp((203125^(3/4)*(-19758816)^(1/4)*i)/203125)))/(17563392*exp((203125^(3/4)*(-19758816)^(1/4))/203125))...etc (continues for another 25,000 char or so)
The expression is a function of x, and appears as a 1x1 symbol. I convert "A" to a function like so:
B=matlabFunction(A)
I would now like to plot B versus x for several values of x. I tried defining x and then using plot(x,B), but the error message says that conversion from double to sym is not possible. Can this be plotted? What am I missing?
Thank you! Kaitlin

2012 年 9 月 11 日

### Matt Fig (view profile)

2012 年 9 月 11 日
採用された回答

When you make a function, you should use it like a function...
syms x
A = 3*x + 5*x^3;
B = matlabFunction(A);
x = 0:.1:10;
plot(x,B(x))

K

2012 年 9 月 12 日
Thank you!