VZ_LOG_(3MVEC) Vector Math Library Functions VZ_LOG_(3MVEC)

## NAME

vz_log_, vc_log_ - vector complex logarithm functions

## SYNOPSIS

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

void vz_log_(int *n, double complex * restrict z,
int *stridez, double _complex * restrict w, int *stridew);

void vc_log_(int *n, float complex * restrict z,
int *stridez, float complex * restrict w, int *stridew);

## DESCRIPTION

These functions evaluate the complex function log(z) 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, vz_log_(n, z, sz, w, sw) computes w[i * *sw] = log(z[i *
*sz]) for each i = 0, 1, ..., *n - 1. The vc_log_() function performs the
same computation for single precision data.

These functions are not guaranteed to deliver results that are identical
to the results of the clog(3M) functions given the same arguments.

## 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.

Unlike the c99 clog(3M) functions, the vector complex exponential
functions make no attempt to handle special cases and exceptions; they
simply use textbook formulas to compute a complex exponential in terms of
real elementary functions. As a result, these functions can raise
different exceptions and/or deliver different results from clog().

## ATTRIBUTES

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

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