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   6 .TH vcospi_ 3MVEC "14 Dec 2007" "SunOS 5.11" "Vector Math Library Functions"
   7 .SH NAME
   8 vcospi_, vcospif_ \- vector cospi functions
   9 .SH SYNOPSIS
  10 .LP
  11 .nf
  12 cc [ \fIflag\fR\&.\|.\|. ] \fIfile\fR\&.\|.\|. \fB-lmvec\fR [ \fIlibrary\fR\&.\|.\|. ]
  13 
  14 \fBvoid\fR \fBvcospi_\fR(\fBint *\fR\fIn\fR, \fBdouble * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
  15      \fBdouble * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR);
  16 .fi
  17 
  18 .LP
  19 .nf
  20 \fBvoid\fR \fBvcosfpi_\fR(\fBint *\fR\fIn\fR, \fBfloat * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
  21      \fBfloat * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR);
  22 .fi
  23 
  24 .SH DESCRIPTION
  25 .sp
  26 .LP
  27 These functions evaluate the function \fBcospi\fR(\fIx\fR), defined by
  28 \fBcospi\fR(\fIx\fR) =  \fBcos\fR(\c
  29 .if n pi\c
  30 .if t \(*p
  31 \c
  32  * \fIx\fR), for an entire vector of values at once. The first parameter
  33 specifies the number of values to compute. Subsequent parameters specify the
  34 argument and result vectors. Each vector is described by a pointer to the first
  35 element and a stride, which is the increment between successive elements.
  36 .sp
  37 .LP
  38 Specifically, \fBvcospi_\fR(\fIn\fR, \fIx\fR, \fIsx\fR, \fIy\fR, \fIsy\fR)
  39 computes \fIy\fR[\fIi\fR * *\fIsy\fR] = \fBcospi\fR(\fIx\fR[\fIi\fR *
  40 *\fIsx\fR]) for each \fIi\fR = 0, 1, ..., *\fIn\fR - 1. The \fBvcospif_()\fR
  41 function performs the same computation for single precision data.
  42 .sp
  43 .LP
  44 Non-exceptional results are accurate to within a unit in the last place.
  45 .SH USAGE
  46 .sp
  47 .LP
  48 The element count *\fIn\fR must be greater than zero. The strides for the
  49 argument and result arrays can be arbitrary integers, but the arrays themselves
  50 must not be the same or overlap. A zero stride effectively collapses an entire
  51 vector into a single element. A negative stride causes a vector to be accessed
  52 in descending memory order, but note that the corresponding pointer must still
  53 point to the first element of the vector to be used; if the stride is negative,
  54 this will be the highest-addressed element in memory. This convention differs
  55 from the Level 1 BLAS, in which array parameters always refer to the
  56 lowest-addressed element in memory even when negative increments are used.
  57 .sp
  58 .LP
  59 These functions assume that the default round-to-nearest rounding direction
  60 mode is in effect. On x86, these functions also assume that the default
  61 round-to-64-bit rounding precision mode is in effect. The result of calling a
  62 vector function with a non-default rounding mode in effect is undefined.
  63 .sp
  64 .LP
  65 These functions handle special cases and exceptions in the spirit of IEEE 754.
  66 In particular,
  67 .RS +4
  68 .TP
  69 .ie t \(bu
  70 .el o
  71 \fBcospi\fR(NaN) is NaN,
  72 .RE
  73 .RS +4
  74 .TP
  75 .ie t \(bu
  76 .el o
  77 \fBcospi\fR(\(+-Inf) is NaN, and  an  invalid operation exception is raised.
  78 .RE
  79 .sp
  80 .LP
  81 An application wanting to check for exceptions should call
  82 \fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On
  83 return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR |
  84 \fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been
  85 raised. The application can then examine the result or argument vectors for
  86 exceptional values. Some vector functions can raise the inexact exception even
  87 if all elements of the argument array are such that the numerical results are
  88 exact.
  89 .SH ATTRIBUTES
  90 .sp
  91 .LP
  92 See \fBattributes\fR(5) for descriptions of the following attributes:
  93 .sp
  94 
  95 .sp
  96 .TS
  97 tab() box;
  98 cw(2.75i) |cw(2.75i) 
  99 lw(2.75i) |lw(2.75i) 
 100 .
 101 ATTRIBUTE TYPEATTRIBUTE VALUE
 102 _
 103 Interface StabilityCommitted
 104 _
 105 MT-LevelMT-Safe
 106 .TE
 107 
 108 .SH SEE ALSO
 109 .sp
 110 .LP
 111 \fBfeclearexcept\fR(3M), \fBfetestexcept\fR(3M), \fBattributes\fR(5)