# vcospi_(3mvec) [opensolaris man page]

```vcospi_(3MVEC)						   Vector Math Library Functions					    vcospi_(3MVEC)

NAME
vcospi_, vcospif_ - vector cospi functions

SYNOPSIS
cc [ flag... ] file... -lmvec [ library... ]

void vcospi_(int *n, double * restrict x, int *stridex,
double * restrict y, int *stridey);

void vcosfpi_(int *n, float * restrict x, int *stridex,
float * restrict y, int *stridey);

DESCRIPTION
These  functions  evaluate  the	function  cospi(x),  defined by cospi(x) =  cos(pi * x), for an entire vector of values at once. The first
parameter specifies the number of values to compute. Subsequent parameters  specify  the  argument  and	result	vectors.  Each	vector	is
described by a pointer to the first element and a stride, which is the increment between successive elements.

Specifically, vcospi_(n, x, sx, y, sy) computes y[i * *sy] = cospi(x[i * *sx]) for each i = 0, 1, ..., *n - 1. The vcospif_() function per-
forms the same computation for single precision data.

Non-exceptional results are accurate to within a unit in the last place.

USAGE
The element count *n must be greater than zero. The strides for the argument and result arrays can be arbitrary integers,  but  the  arrays
themselves  must  not be the same or overlap. A zero stride effectively collapses an entire vector into a single element. A negative stride
causes a vector to be accessed in descending memory order, but note that the corresponding pointer must still point to the first element of
the  vector  to	be used; if the stride is negative, this will be the highest-addressed element in memory. This convention differs from the
Level 1 BLAS, in which array parameters always refer to the lowest-addressed element in memory even when negative increments are used.

These functions assume that the default round-to-nearest rounding direction mode is in effect. On x86, these functions also assume that the
default	round-to-64-bit  rounding precision mode is in effect. The result of calling a vector function with a non-default rounding mode in
effect is undefined.

These functions handle special cases and exceptions in the spirit of IEEE 754. In particular,

o	  cospi(NaN) is NaN,

o	  cospi(+-Inf) is NaN, and  an	invalid operation exception is raised.

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before  calling	these  functions.  On  return,	if
fetestexcept(FE_INVALID	|  FE_DIVBYZERO  | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. The application can then
examine the result or argument vectors for exceptional values. Some vector functions can raise the inexact exception even if  all  elements
of the argument array are such that the numerical results are exact.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Committed 		   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+

feclearexcept(3M), fetestexcept(3M), attributes(5)

SunOS 5.11							    14 Dec 2007 						    vcospi_(3MVEC)```

## Check Out this Related Man Page

```vrsqrt_(3MVEC)						   Vector Math Library Functions					    vrsqrt_(3MVEC)

NAME
vrsqrt_, vrsqrtf_ - vector reciprocal square root functions

SYNOPSIS
cc [ flag... ] file... -lmvec [ library... ]

void vrsqrt_(int *n, double * restrict x, int *stridex,
double * restrict y, int *stridey);

void vrsqrtf_(int *n, float * restrict x, int *stridex,
float * restrict y, int *stridey);

DESCRIPTION
These functions evaluate the function rsqrt(x), defined by rsqrt(x) = 1 / sqrt(x), for an entire vector of values at once. The first param-
eter specifies the number of values to compute. Subsequent parameters specify the argument and result vectors. Each vector is described	by
a pointer to the first element and a stride, which is the increment between successive elements.

Specifically, vrsqrt_(n, x, sx, y, sy) computes y[i * *sy] = rsqrt(x[i * *sx]) for each i = 0, 1, ..., *n - 1. The vrsqrtf_() function per-
forms the same computation for single precision data.

These functions are not guaranteed to deliver results that are identical to the results of evaluating 1.0 / sqrt(x) given  the  same  argu-
ments. Non-exceptional results, however, are accurate to within a unit in the last place.

USAGE
The  element  count  *n must be greater than zero. The strides for the argument and result arrays can be arbitrary integers, but the arrays
themselves must not be the same or overlap. A zero stride effectively collapses an entire vector into a single element. A  negative  stride
causes a vector to be accessed in descending memory order, but note that the corresponding pointer must still point to the first element of
the vector to be used; if the stride is negative, this will be the highest-addressed element in memory. This convention	differs  from  the
Level 1 BLAS, in which array parameters always refer to the lowest-addressed element in memory even when negative increments are used.

These functions assume that the default round-to-nearest rounding direction mode is in effect. On x86, these functions also assume that the
default round-to-64-bit rounding precision mode is in effect. The result of calling a vector function with a non-default rounding  mode	in
effect is undefined.

These functions handle special cases and exceptions in the spirit of IEEE 754. In particular,

o	  if x < 0, rsqrt(x) is NaN, and an invalid operation exception is raised,

o	  rsqrt(NaN) is NaN,

o	  rsqrt(+Inf) is +0,

o	  rsqrt(+-0) is +-Inf, and a division-by-zero exception is raised.

An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. The  application  can  then
examine	the  result or argument vectors for exceptional values. Some vector functions can raise the inexact exception even if all elements
of the argument array are such that the numerical results are exact.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Committed 		   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+