Yondom - Math - Matrix

Matrices

First a word about vectors: vectors can be thought of as points in a system of coordinates such as (x, y).  That is a simple row vector.  As a column vector it would be written

x
y

Matrices have two dimensions.  Matrices are usually square arrays of integers.  A matrix transforms or maps a column vector by multiplying the coordinates by one row at a time, thus:


Composition of Matrices

We can combine matrices by multiplying the columns of the second (B, say) by the rows of the first (A, say), thus:


Every term of the result is the sum of n row-term × column-term multiplications, where n is the dimension of the matrices.


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