I read the tutorial, but I couldn't find element by element multiply and divide, I need a simple function just like .* or ./ in Matlab or Octave, this function means multiply two same size matrix element by element

Can any one tell me how to manipulate it?

If mat1 and mat2 are of type Matrix, you can do either mat1.cwiseProduct(mat2) to get the component-wise product. Similarly, mat1.cwiseQuotient(mat2) gives component-wise division.

If arr1 and arr2 are of type Array, you can simply do arr1 * arr2 and arr1 / arr2.

I think "Tutorial page 3 - The Array class and coefficient-wise operations" at http://eigen.tuxfamily.org/dox-devel/Tu ... Class.html explains all this.