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