I am unsure of how I am getting this error

Question

Cameron Paterson 2021-10-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1573288-i-am-unsure-of-how-i-am-getting-this-error

回答： David Hill 2021-10-27

r=linspace(0.001,1,1000);
s=0.75.*((r.^3)/(exp(1)^(.75.*r)));
subplot(2,2,1)
plot(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,2)
semilogy(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,3)
semilogx(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,4)
loglog(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on

Error using ^ (line 51)

Incorrect dimensions for raising a matrix to a power. Check that the matrix is square and the power is a

scalar. To perform elementwise matrix powers, use '.^'.

Error in HW8P3 (line 2)

s=0.75.*((r.^3)/(exp(1)^(.75.*r)));

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Stephen23 2021-10-27

编辑：Stephen23 2021-10-27

"I am unsure of how I am getting this error"

Did you read the last part of the error message?: To perform elementwise matrix powers, use '.^'.

You probably need to use array operations, not matrix operations:

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html

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Answer 1

David Hill 2021-10-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1573288-i-am-unsure-of-how-i-am-getting-this-error#answer_818253

在 MATLAB Online 中打开

r=linspace(0.001,1,1000);
s=0.75*((r.^3)./(exp(1).^(.75*r)));%error is here (multiplying by scalar does not need .*, but you need elementwise operations for matrix operations is needed)
subplot(2,2,1)
plot(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,2)
semilogy(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,3)
semilogx(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on
subplot(2,2,4)
loglog(r,s)
xlabel('x')
ylabel('y(x)')
axis([min(r) max(r) min(s) max(s)])
grid on