Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F82647629
drscl.f
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Thu, Sep 12, 15:38
Size
4 KB
Mime Type
text/html
Expires
Sat, Sep 14, 15:38 (2 d)
Engine
blob
Format
Raw Data
Handle
20707776
Attached To
rLAMMPS lammps
drscl.f
View Options
*>
\
brief
\
b
DRSCL
multiplies
a
vector
by
the
reciprocal
of
a
real
scalar
.
*
*
===========
DOCUMENTATION
===========
*
*
Online
html
documentation
available
at
*
http
:
//
www
.
netlib
.
org
/
lapack
/
explore
-
html
/
*
*>
\
htmlonly
*>
Download
DRSCL
+
dependencies
*>
<
a
href
=
"http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/drscl.f"
>
*>
[
TGZ
]
</
a
>
*>
<
a
href
=
"http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/drscl.f"
>
*>
[
ZIP
]
</
a
>
*>
<
a
href
=
"http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/drscl.f"
>
*>
[
TXT
]
</
a
>
*>
\
endhtmlonly
*
*
Definition
:
*
===========
*
*
SUBROUTINE
DRSCL
(
N
,
SA
,
SX
,
INCX
)
*
*
..
Scalar
Arguments
..
*
INTEGER
INCX
,
N
*
DOUBLE PRECISION
SA
*
..
*
..
Array
Arguments
..
*
DOUBLE PRECISION
SX
(
*
)
*
..
*
*
*>
\
par
Purpose
:
*
=============
*>
*>
\
verbatim
*>
*>
DRSCL
multiplies
an
n
-
element
real
vector
x
by
the
real
scalar
1
/
a
.
*>
This
is
done
without
overflow
or
underflow
as
long
as
*>
the
final
result
x
/
a
does
not
overflow
or
underflow
.
*>
\
endverbatim
*
*
Arguments
:
*
==========
*
*>
\
param
[
in
]
N
*>
\
verbatim
*>
N
is
INTEGER
*>
The
number
of
components
of
the
vector
x
.
*>
\
endverbatim
*>
*>
\
param
[
in
]
SA
*>
\
verbatim
*>
SA
is
DOUBLE PRECISION
*>
The
scalar
a
which
is
used
to
divide
each
component
of
x
.
*>
SA
must
be
>=
0
,
or
the
subroutine
will
divide
by
zero
.
*>
\
endverbatim
*>
*>
\
param
[
in
,
out
]
SX
*>
\
verbatim
*>
SX
is
DOUBLE PRECISION
array
,
dimension
*>
(
1
+
(
N
-
1
)
*
abs
(
INCX
))
*>
The
n
-
element
vector
x
.
*>
\
endverbatim
*>
*>
\
param
[
in
]
INCX
*>
\
verbatim
*>
INCX
is
INTEGER
*>
The
increment
between
successive
values
of
the
vector
SX
.
*>
>
0
:
SX
(
1
)
=
X
(
1
)
and
SX
(
1
+
(
i
-
1
)
*
INCX
)
=
x
(
i
),
1
<
i
<=
n
*>
\
endverbatim
*
*
Authors
:
*
========
*
*>
\
author
Univ
.
of
Tennessee
*>
\
author
Univ
.
of
California
Berkeley
*>
\
author
Univ
.
of
Colorado
Denver
*>
\
author
NAG
Ltd
.
*
*>
\
date
September
2012
*
*>
\
ingroup
doubleOTHERauxiliary
*
*
=====================================================================
SUBROUTINE
DRSCL
(
N
,
SA
,
SX
,
INCX
)
*
*
--
LAPACK
auxiliary
routine
(
version
3.4.2
)
--
*
--
LAPACK
is
a
software
package
provided
by
Univ
.
of
Tennessee
,
--
*
--
Univ
.
of
California
Berkeley
,
Univ
.
of
Colorado
Denver
and
NAG
Ltd
..
--
*
September
2012
*
*
..
Scalar
Arguments
..
INTEGER
INCX
,
N
DOUBLE PRECISION
SA
*
..
*
..
Array
Arguments
..
DOUBLE PRECISION
SX
(
*
)
*
..
*
*
=====================================================================
*
*
..
Parameters
..
DOUBLE PRECISION
ONE
,
ZERO
PARAMETER
(
ONE
=
1.0
D
+
0
,
ZERO
=
0.0
D
+
0
)
*
..
*
..
Local
Scalars
..
LOGICAL
DONE
DOUBLE PRECISION
BIGNUM
,
CDEN
,
CDEN1
,
CNUM
,
CNUM1
,
MUL
,
SMLNUM
*
..
*
..
External
Functions
..
DOUBLE PRECISION
DLAMCH
EXTERNAL
DLAMCH
*
..
*
..
External
Subroutines
..
EXTERNAL
DSCAL
*
..
*
..
Intrinsic
Functions
..
INTRINSIC
ABS
*
..
*
..
Executable
Statements
..
*
*
Quick
return if
possible
*
IF
(
N
.LE.
0
)
$
RETURN
*
*
Get
machine
parameters
*
SMLNUM
=
DLAMCH
(
'S'
)
BIGNUM
=
ONE
/
SMLNUM
CALL
DLABAD
(
SMLNUM
,
BIGNUM
)
*
*
Initialize
the
denominator
to
SA
and
the
numerator
to
1.
*
CDEN
=
SA
CNUM
=
ONE
*
10
CONTINUE
CDEN1
=
CDEN
*
SMLNUM
CNUM1
=
CNUM
/
BIGNUM
IF
(
ABS
(
CDEN1
)
.GT.
ABS
(
CNUM
)
.AND.
CNUM
.NE.
ZERO
)
THEN
*
*
Pre
-
multiply
X
by
SMLNUM
if
CDEN
is
large
compared
to
CNUM
.
*
MUL
=
SMLNUM
DONE
=
.FALSE.
CDEN
=
CDEN1
ELSE IF
(
ABS
(
CNUM1
)
.GT.
ABS
(
CDEN
)
)
THEN
*
*
Pre
-
multiply
X
by
BIGNUM
if
CDEN
is
small
compared
to
CNUM
.
*
MUL
=
BIGNUM
DONE
=
.FALSE.
CNUM
=
CNUM1
ELSE
*
*
Multiply
X
by
CNUM
/
CDEN
and
return
.
*
MUL
=
CNUM
/
CDEN
DONE
=
.TRUE.
END IF
*
*
Scale
the
vector
X
by
MUL
*
CALL
DSCAL
(
N
,
MUL
,
SX
,
INCX
)
*
IF
(
.NOT.
DONE
)
$
GO
TO
10
*
RETURN
*
*
End
of
DRSCL
*
END
Event Timeline
Log In to Comment