identity method
void
identity()
Sets the matrix to identity
@todo Should perhaps be renamed to setIdentity()
to be more clear.
@todo Create another function that immediately creates an identity matrix eg. eye()
Implementation
void identity(){
final e = elements;
e[0] = 1;
e[1] = 0;
e[2] = 0;
e[3] = 0;
e[4] = 1;
e[5] = 0;
e[6] = 0;
e[7] = 0;
e[8] = 1;
}