How do i correct this mistake in my matlab program? Please help.

ex(1)=lx/J      %%first i term in ex matrix
ex(2)=mx/J      %%second j term in ex matrix
ex(3)=nx/J      %%third k term in ex matrix

for i=1:9
    N_matrix(1,i)=N(rem(i,3))*ex(i / 3);(ERROR HERE)
end

Attempted to access ex(0.333333); index must be a positive integer or logical.

Error in practisee2 (line 225)
    N_matrix(1,i)=N(rem(i,3))*ex(i / 3);

[Walter Roberson]

Attempted to access ex(0.333333); index must be a positive integer or logical.

That is not a MATLAB error message. It might be an Octave error message. MATLAB error messages do not mention the value of the invalid subscript.

[Virajan Verma]

@Walter This is a Matlab error message. I am currently using it.

[Walter Roberson]

Ah, a very old MATLAB.

[Virajan Verma]

Yes. It is 2015 version. How do i eliminate the error??

[Walter Roberson]

First you explain what you intend it to mean. In one of your related posts you said that ex is a function, but it was clear that you had initialized ex as a variable.

Answer 1

[madhan ravi]

ex(i / 3); Should be an integer value not a float

So try ex(i)/3

[Virajan Verma]

This changes the meaning of the expression, although the error is removed.

[madhan ravi]

you have to explain what you want to do learn about indexing first

[Walter Roberson]

What is the intended meaning of ex(i/3) when i is 1 ?