Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

?lange

Returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix.

Syntax

val
=
slange
(
norm
,
m
,
n
,
a
,
lda
,
work
)
val
=
dlange
(
norm
,
m
,
n
,
a
,
lda
,
work
)
val
=
clange
(
norm
,
m
,
n
,
a
,
lda
,
work
)
val
=
zlange
(
norm
,
m
,
n
,
a
,
lda
,
work
)
Include Files
  • mkl.fi
Description
The function
?lange
returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real/complex matrix
A
.
Input Parameters
The data types are given for the Fortran interface.
norm
CHARACTER*1
.
Specifies the value to be returned by the routine:
=
'M'
or
'm':
val
=
max
(
abs
(
A
i
j
))
, largest absolute value of the matrix
A
.
=
'1'
or
'O'
or
'o':
val
=
norm1
(
A
)
, 1-norm of the matrix
A
(maximum column sum),
=
'I'
or
'i':
val
=
normI
(
A
)
, infinity norm of the matrix
A
(maximum row sum),
=
'F'
,
'f'
,
'E'
or
'e':
val
=
normF
(
A
)
, Frobenius norm of the matrix
A
(square root of sum of squares).
m
INTEGER
.
The number of rows of the matrix
A
.
m
0
. When
m
= 0
,
?lange
is set to zero.
n
INTEGER
.
The number of columns of the matrix
A
.
n
0
. When
n
= 0
,
?lange
is set to zero.
a
REAL
for
slange
DOUBLE PRECISION
for
dlange
COMPLEX
for
clange
DOUBLE COMPLEX
for
zlange
Array,
DIMENSION
(
lda
,
n
).
Array
a
contains the
m
-by-
n
matrix
A
.
lda
INTEGER
.
The leading dimension of the array
a
.
.
work
REAL
for
slange
and
clange
.
DOUBLE PRECISION
for
dlange
and
zlange
.
Workspace array,
DIMENSION
max(1,
lwork
)
, where
lwork
m