Array indices must be positive integers

4 次查看（过去 30 天）
Dan
Dan 2023-5-5
回答： Steven Lord 2023-5-5
I'm trying to use the midpoint formula to compute the value of the integral, but it keeps showing the error message "Array indices must be positive integrs or logical values." I don't know how to solve it. Thanks!

请先登录，再回答此问题。

采纳的回答

Steven Lord
Steven Lord 2023-5-5
The variable func is a vector, the value of the function handle f evaluated at the points in x. On the line where you compute mid_val you're indexing into that vector with values that likely aren't integer values. Were you trying to evalate the function handle f at those points? If so use f instead of func on that line.

更多回答（1 个）

VBBV
VBBV 2023-5-5
编辑：VBBV 2023-5-5
Ran in:
assign the func to f inside the custom function as below , probably you mean this
f = @(x) x.^3.*exp(-x.^3);
a = 0; b = 10; n = 100;
mid_val = integral_mid(f,a,b,n)
mid_val = 0.2977
function mid_val = integral_mid(f,a,b,n)
h = (b-a)/n;
%x = a:h:b;
% assign the func to f
func = f;
xmid = (a+h/2):h:b;
mid_val = h*sum(func(xmid));
end

类别

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

标签

产品


版本

R2023a

Community Treasure Hunt

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

Start Hunting!

Translated by