HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010

LSQ(<matrix1>,<matrix2>)
The least squares function displays the minimum norm least squares matrix (or vector).
LU(<matrix>)
This
LU Decomposition function is similar to the LQ function on the previous page. It factors a square matrix
into three matrices, returning them in the form of a list variable.
{[[lower triangular]],[[upper triangular]],[[permutation]]}
The upper triangular has ones on its diagonal. The matrices can be separated in the same method outlined
for the
LQ function.
MAKEMAT(<expression>,<rows>,<columns>)
The MAKEMAT function is used, mainly by programmers to manufacture a matrix with dimensions rows ×
columns, using the supplied expression to calculate each element.
Eg.
MAKEMAT(0,3,3) returns a 3×3 zero matrix,
Note: If the expression contains the variables
I and J, then the calculation for each element substitutes the
current row number for
I and the current column number for J during the calculation.
⎡
234
⎤
⎥
Eg.
MAKEMAT(I+J,3,3) returns the matrix
⎢
⎢
345
⎥
⎢
456
⎥
⎦
⎣
QR(<matrix>)
The
QR function is similar to the LQ function on the previous page. It factors an m x n matrix into three
matrices, returning them in the form of a list variable.
{[[m×m orthogonal]],[[m×n uppertrapezoidal]],[[n×n permutation]]}
RANK(<matrix>)
This function returns the rank of a rectangular matrix.
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