HP 49g+ - Manual (Page 630)

Page 18-63
« Open program
x y p Enter lists x and y, and number p
« Open subprogram1
x SIZE n Determine size of x list
« Open subprogram 2
x VANDERMONDE Place x in stack, obtain V
n
IF ‘p<n-1’ THEN This IF is step 3 in algorithm
n Place n in stack
p 2 + Calculate p+1
FOR j Start loop, j = n-1 to p+1, step = -1
j COL − DROP Remove column, drop from stack
-1 STEP Close FOR-STEP loop
ELSE
IF ‘p>n-1’ THEN
n 1 +
Calculate n+1
p 1 + Calculate p+1
FOR j Start loop with j = n, n+1, …, p+1.
x j ^ Calculate x j , as a list
OBJ ARRY Convert list to array
j COL+ Add column to matrix
NEXT Close FOR-NEXT loop
END Ends second IF clause.
END Ends first IF clause. Produces X
y OBJ ARRY Convert list y to an array
X yv Enter matrix and array as X and y
« Open subprogram 3
X yv MTREG X and y used by program MTREG
NUM If needed, converts to floating point
b Resulting vector passed as b
« Open subprogram 4
b yv Place b and yv in stack
X b * Calculate X⋅b
- Calculate e = y - X⋅b
ABS SQ DUP Calculate SSE, make copy
y ΣLIST n / Calculate y
n 1 LIST SWAP CON Create vector of n values of y