(38G) 40G: Matrix Power Programme

[Gerald H]

Edit: Amended to include negative powers.

Edit: Programme slightly more elegant.

Edit: Amended to avoid errors for some powers > 5*10^11.

A lack in the 38G & 40G (not the 40gs) is the inability to find integer powers ≠ 2 or -1 of matrices.

This programme supplies the lack.

Store the matrix to power in M1, enter the integer power on the stack in HOME view & activate the programme.

The powered matrix is recalled as Ans in HOME view & is also stored in M2.

M1 remains unchanged.

Code:

Ans►N:
IFTE(N<0,INVERSE(M1),M1)►M3:
ABS(N)►N:
SIZE(M1):
IDENMAT(Ans(1))►M2:
WHILE N
REPEAT
IF
N MOD 2
THEN
M3*M2►M2:
N-1►N:
END:
M3^2►M3:
N/2►N:
END:
M2: