when I enter n = 10, it reports an error Invalid second data argument

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0 个投票

function f=vedangsong()
syms t n i w f(t)
Ao=input('nhap Ao: ');
n=input('nhap so bac hai n: ');
w=input('nhap tan so goc w: ');
for i = 1:n
   tb1=['nhap A',num2str(i),': ' ]; 
   A(num2str(i))=input(tb1);
   tb2=['nhap B',num2str(i),': ' ];
   B(num2str(i))=input(tb2);
end
f(t)=0
for i=1:n
   s=sin(2*pi*i*w*t)
   c=cos(2*pi*i*w*t)
   g= A(num2str(i))*s + B(num2str(i))*c
   f(t)=f(t) + g
end
f(t) =Ao + f(t)
t=linspace(0,1/w,300)
plot(t,f(t),'k')
title('Dang song trong mien thoi gian')
xlabel('Truc t')
ylabel('f(t)')
legend('f(t)')
end

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Walter Roberson 2019-4-25

在 MATLAB Online 中打开

What input values should we use to test with?

Note that your statement

B(num2str(i))=input(tb2)

will not create variables named B1, B2, B3, and so on. Instead, it will be assignments to B('1'), B('2'), B('3') and so on, which is the same as assigning to B(49), B(50), B(51)

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Stephen23 2019-4-25

在 MATLAB Online 中打开

This is not a good sign:

B(num2str(i)) = ...

Dynamically creating or accessing variable names is one way that beginners force themselves into writing slow, complex, buggy code. Read this to know why:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

You should just use indexing. Indexing is simple, neat, easy to debug, and very efficient (unlike what you are trying to do).

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