RTL Routines, MTH$, BLAS1$VxAXPY
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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VMS Help RTL Routines, MTH$, BLAS1$VxAXPY *Conan The Librarian (sorry for the slow response - running on an old VAX) |
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The Multiply a Vector by a Scalar and Add a Vector routine
computes ax + y, where a is a scalar number and x and y are n-
element vectors.
Format
BLAS1$VSAXPY n ,a ,x ,incx ,y ,incy
BLAS1$VDAXPY n ,a ,x ,incx ,y ,incy
BLAS1$VGAXPY n ,a ,x ,incx ,y ,incy
BLAS1$VCAXPY n ,a ,x ,incx ,y ,incy
BLAS1$VZAXPY n ,a ,x ,incx ,y ,incy
BLAS1$VWAXPY n ,a ,x ,incx ,y ,incy
Use BLAS1$VSAXPY for single-precision real operations.
Use BLAS1$VDAXPY for double-precision real (D-floating)
operations.
Use BLAS1$VGAXPY for double-precision real (G-floating)
operations.
Use BLAS1$VCAXPY for single-precision complex operations.
Use BLAS1$VZAXPY for double-precision complex (D-floating)
operations.
Use BLAS1$VWAXPY for double-precision complex (G-floating)
operations.
| 1 - Returns |
None.
| 2 - Arguments |
n
OpenVMS usage:longword_signed
type: longword integer (signed)
access: read only
mechanism: by reference
Number of elements in vectors x and y. The n argument is the
address of a signed longword integer containing the number of
elements. If n is less than or equal to 0, then y is unchanged.
a
OpenVMS usage:floating_point or complex_number
type: F_floating, D_floating, G_floating real or
F_floating, D_floating, G_floating complex
access: read only
mechanism: by reference, array reference
Scalar multiplier for the array x. The a argument is the address
of a floating-point or floating-point complex number that is this
multiplier. If a equals 0, then y is unchanged. If a shares a
memory location with any element of the vector y, results are
unpredictable. Specify the same data type for arguments a, x, and
y.
x
OpenVMS usage:floating_point or complex_number
type: F_floating, D_floating, G_floating real or
F_floating, D_floating, G_floating complex
access: read only
mechanism: by reference, array reference
Array containing the elements to be accessed. All elements of
array x are accessed only if the increment argument of x, called
incx, is 1. The x argument is the address of a floating-point or
floating-point complex number that is this array. The length of
this array is at least:
1+(n-1)*|incx|
where:
n = number of vector elements specified in n
incx= increment argument for the array x specified in incx
Specify the data type as follows:
Routine Data Type for x
BLAS1$VSAXPY F-floating real
BLAS1$VDAXPY D-floating real
BLAS1$VGAXPY G-floating real
BLAS1$VCAXPY F-floating complex
BLAS1$VZAXPY D-floating complex
BLAS1$VWAXPY G-floating complex
If any element of x shares a memory location with an element of
y, the results are unpredictable.
incx
OpenVMS usage:longword_signed
type: longword integer (signed)
access: read only
mechanism: by reference
Increment argument for the array x. The incx argument is the
address of a signed longword integer containing the increment
argument. If incx is greater than or equal to 0, then x is
referenced forward in array x; that is, xi is referenced in:
x(1+(i-1)*incx)
where:
x = array specified in x
i = element of the vector x
incx= increment argument for the array x specified in incx
If incx is less than 0, then x is referenced backward in array x;
that is, xi is referenced in:
x(1+(n-i)*|incx|)
where:
x = array specified in x
n = number of vector elements specified in n
i = element of the vector x
incx= increment argument for the array x specified in incx
y
OpenVMS usage:floating_point or complex_number
type: F_floating, D_floating, G_floating real or
F_floating, D_floating, G_floating complex
access: modify
mechanism: by reference, array reference
On entry, array containing the elements to be accessed. All
elements of array y are accessed only if the increment argument
of y, called incy, is 1. The y argument is the address of a
floating-point or floating-point complex number that is this
array. The length of this array is at least:
1+(n-1)*|incy|
where:
n = number of vector elements specified in n
incy= increment argument for the array y specified in incy
Specify the data type as follows:
Routine Data Type for y
BLAS1$VSAXPY F-floating real
BLAS1$VDAXPY D-floating real
BLAS1$VGAXPY G-floating real
BLAS1$VCAXPY F-floating complex
BLAS1$VZAXPY D-floating complex
BLAS1$VWAXPY G-floating complex
If n is less than or equal to 0, then y is unchanged. If any
element of x shares a memory location with an element of y, the
results are unpredictable.
On exit, y contains an array of length at least:
1+(n-1)*|incy|
where:
n = number of vector elements specified in n
incy= increment argument for the array y specified in incy
After the call to BLAS1$VxAXPY, yi is set equal to:
y[i]+a*x[i]
where:
y = the vector y
i = element of the vector x or y
a = scalar multiplier for the vector x specified in a
x = the vector x
incy
OpenVMS usage:longword_signed
type: longword integer (signed)
access: read only
mechanism: by reference
Increment argument for the array y. The incy argument is the
address of a signed longword integer containing the increment
argument. If incy is greater than or equal to 0, then y is
referenced forward in array y; that is, (y[i]) is referenced
in:
y(1+(i-1)*incy)
where:
y = array specified in y
i = element of the vector y
incy= increment argument for the array y specified in incy
If incy is less than 0, then y is referenced backward in array y;
that is, (y[i]) is referenced in:
y(1+(n-i)*|incy|)
where:
y = array specified in y
n = number of vector elements specified in n
i = element of the vector y
incy= increment argument for the array y specified in incy
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