HP 15C Quick Reference Manual page 8

STO g A-E, (i) Same as above but the stack's Y register contains the row number and
X the column number, starting from 1.
The value must be present in Z.
Both X & Y will be popped from the stack so that the value ends up in
X.
STO g A-E, (i) Same as above but the stack's Y register contains the row number and
RCL g A-E, (i) X the column number, starting from 1.
RCL will pop X & Y from the stack and then push the matrix element
into X
STO MATRIX X is a number: Store the value of X in all matrix elements.
A-E X is a matrix: Copy matrix in X to the specified matrix. The destination
matrix will be redimensioned
RCL MATRIX Put the matrix descriptor of the specified matrix in X
A-E
x↔ A-E, (i) Exchange X with the matrix element of A-E specified by R1/R0.
R1 & R0 are not affected
DSE A-E, (i) Decrements/increments the matrix element of A-E or (i) specified by
ISG A-E, (i) R1/R0. R1 & R0 are not affected. See DSE & ISG in section
Programming
Specifies the result matrix (default is A). This is the matrix that will hold
RESULT A-E
the result of a matrix operation. Not all operations require a result
matrix. The result matrix will automatically be dimensioned so that it
can properly hold the result. For some matrix operations the result
matrix can be identical to one of the input matrices
STO RESULT When a matrix descriptor is already present in X then this matrix will be
used as the result matrix
RCL RESULT Recalls the descriptor of the result matrix into X
Result in X
Unary matrix
operations
CHS None
1/x Descriptor of RESULT.
X must be square
MATRIX 4 None
MATRIX 7 Row norm: Largest sum
of absolute values of all
rows
MATRIX 8 Frobenius or Euclidian
norm of X: Square root
of the sum of all matrix
elements
MATRIX 9 Determinat of matrix.
X must be square
Scalar matrix operations
HP-15C
Effect on matrix
specified in X
Changes sign of all
matrix elements
None as long as
X<>RESULT
Replaced by
transpose X T
None
None
None as long as
X<>RESULT
8
Effect on RESULT
matrix
None as long as
X<>RESULT
Inverse of matrix X.
If it is singular, then
1/x will calculate the
inverse of a matrix
that is close to X.
None as long as
X<>RESULT
None
None
LU decomposition of
matrix X