Why am I getting: "invalid syntax at "(" .A might be missing a closing ")"

What is messing here??

  source = ((-4*A^2*alpha)-(9*B^2*alpha))*(cos^2( (2*A) * XX).* sin^2( (3*B) * YY))...
      -( (5/2)*4*A^2*alpha+(5/2)*9*B^2*alpha)*(cos( (2*A) * XX).* sin( (3*B) * YY))...
       + ((4*A^2*alpha)*(sin^2((2*A) * XX).* sin^2( (3*B) * YY)))...
       + ((9*B^2*alpha)*(cos^2((2*A) * XX).* cos^2( (3*B) * YY))));
  

Error at first line where the cosine squared is

  (cos^2( .. %underneath the paranthesis infront of cos^2
  

I don't understand???

[Stephen23]

The functions COS and SIN require an input argument, so many of your function calls are invalid:

cos^2(..)  % invalid sytanx (COS has no input)
cos(..)^2  % valid syntax

I suspect that you actually want POWER .^ and not MPOWER ^

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

[Jamie Al]

I see!! Thanks!

Answer 1

[Walter Roberson]

In MATLAB, cos^2(x) and sin^2(x) are not valid operations. These will be interpreted as cos()^2(x) and sin()^2(x) which would involve invoking cos or sin with no parameters, and trying to raise the result to an expression that as 2 followed by an expression in () ... which would be intepreted as an invalid indexing operation since constants such as 2 cannot be indexed.

You need to instead code cos(x)^2 and sin(x)^2 .

... You should probably vectorize along the way.

[Jamie Al]

Is this correct here:

cos((2*A) * XX).^2 .*.. 

I mean the place of the dot operator?

Answer 2

[KSSV]

You are missing an operator, multiplication operator at many places.

  (cos^2*( .. %underneath 

[Jamie Al]

Thanks