This function calculates the Modal Assurance Criterion Matrix.
Input: Modal shapes
Output: MAC Matrix

Modal shapes can be determined manually through the following steps:
Step 1: Derive the equation of motion for the whole system.
Step 2: Solve the Eigen value problem det[K-w^2M]=0
Step 3: Plug-in the value of w*2 (Natural frequency) into [K-w^2M]*phi=0

The modal shapes are normally obtained using sensors and computer programs therefore in such a case, they only need to be loaded.