when i'm trying to run the below program, it is showing the following error. ??? Undefined function or variable 'z'. Error in ==> integration at 6 I=integrat​e(z*(cosh(​k*(d+z)))^​2,z,0,hc);

1 次查看（过去 30 天）
Aiswaria
Aiswaria 2013-2-18
the program is as follows:
clc;
d=input('d=');
L=input('L=');
hc=input('hc=');
k=2*pi/L;
I=integrate(z*(cosh(k*(d+z)))^2,z,0,hc)
Someone please help me...
thank you

请先登录，再回答此问题。

回答（1 个）

Walter Roberson
Walter Roberson 2013-2-18
You are confusing numeric integration with symbolic integration.
symbolic integration uses int() instead of integrate(), and requires that the free variable have been pre-defined as a symbol (unless quoted strings are passed in.) symbolic integration requires the integration variable as the second parameter, the way you have passed it in.
syms z
I_symbolic = int(z*(cosh(k*(d+z)))^2,z,0,hc));
I_numeric = double(I_symbolic);
Numeric integration cannot have any free variables, and must have a function as its first parameter. The second parameter is never the variable of integration for numeric integration.
I_numeric = integrate(@(z) z*(cosh(k*(d+z)))^2,0,hc);
  1 个评论
Aiswaria
Aiswaria 2013-2-18
i tried that but its saying like ??? Undefined function or method 'integrate' for input arguments of type 'function_handle'.
Error in ==> integration at 7 I_numeric = integrate(@(z) z*(cosh(k*(d+z)))^2,0,hc)

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Calculus 的更多信息

标签

尚未输入任何标签。

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by