HP 50g Graphing Calculator - Manual (Page 320)

Page 10-19
In this result, the first column occupies the highest stack level after
decomposition, and stack level 1 is occupied by the number of columns of the
original matrix. The matrix does not survive decomposition, i.e., it is no longer
available in the stack.
Function COL →
Function COL → has the opposite effect of Function → COL, i.e., given n vectors
of the same length, and the number n, function COL builds a matrix by
placing the input vectors as columns of the resulting matrix. Here is an example
in ALG mode. The command used was:
COL ([1,2,3],[4,5,6],[7,8,9],3)
In RPN mode, place the n vectors in stack levels n+1, n, n-1,…,2, and the
number n in stack level 1. With this set up, function COL places the vectors
as columns in the resulting matrix. The following figure shows the RPN stack
before and after using function COL .
Function COL+
Function COL+ takes as argument a matrix, a vector with the same length as
the number of rows in the matrix, and an integer number n representing the
location of a column. Function COL+ inserts the vector in column n of the
matrix. For example, in ALG mode, we’ll insert the second column in matrix A
with the vector [-1,-2,-3], i.e.,