Re: How to prevent "error: A(I, J) = X: X must be a scalar..." with working matlab code

[Przemek Klosowski]

   I am not interested in adding another special case to the indexed
   array assignment code and after all these years I still don't
   understand precisely what the rules are for matching up dimensions
   with colon indices when the array on the left hand side is undefined
   prior to the assignment.  If someone can clearly explain what the
   rules are, maybe Octave could be compatible.  Does anyone know of
   documentation for this Matlab feature, or is it just something that
   people come to understand in some sort of mystical way?

FWIW, in Matlab 6.5.1

P=12
u= linspace(0,1,P)
x1(:,1)= 0.5.*(u)-0.5
???  In an assignment  A(:,matrix) = B, the number of elements in the subscript 
of A and the number
of columns in B must be the same.

so 'working Matlab code' doesn't even always work in Matlab.