FunctionBinary logarithm
Syntax C/C++#include <VFmath.h>
int VF_log2( fVector Y, fVector X, ui size );
int VFx_log2( fVector Y, fVector X, ui size, float A, float B, float C );
int VPF_log2toC( cfVector Y, pfVector X, ui size );
C++ VecObj#include <OptiVec.h>
int vector<T>::log2( const vector<T>& X );
int vector<T>::x_log2( const vector<polar<T>>& X, const T& A, const T& B, const T& C );
int vector<complex<T>>::log2toC( const vector<T>& X );
Pascal/Delphiuses VFmath;
function VF_log2( Y, X:fVector; size:UIntSize ): IntBool;
function VFx_log2( Y, X:fVector; size:UIntSize; A, B, C:Single ): IntBool;
function VPF_log2toC( Y:cfVector; X:pfVector; size:UIntSize ): IntBool;
CUDA function C/C++#include <cudaVFmath.h>
int cudaVF_log2( fVector d_Y, fVector d_X, ui size );
int cudaVFx_log2( fVector d_Y, fVector d_X, ui size, float A, float B, float C );
int cusdVFx_log2( fVector d_Y, fVector d_X, ui size, float *d_A, float *d_B, float *d_C );
int VFcu_log2( fVector h_Y, fVector h_X, ui size );
int VFxcu_log2( fVector h_Y, fVector h_X, ui size, float A, float B, float C );
CUDA function Pascal/Delphiuses VFmath;
function cudaVF_log2( d_Y, d_X:fVector; size:UIntSize ): IntBool;
function cudaVFx_log2( d_Y, d_X:fVector; size:UIntSize; A, B, C:Single ): IntBool;
function cusdVFx_log2( d_Y, d_X:fVector; size:UIntSize; d_A, d_B, d_C:PSingle ): IntBool;
function VFcu_log2( h_Y, h_X:fVector; size:UIntSize ): IntBool;
function VFxcu_log2( h_Y, h_X:fVector; size:UIntSize; A, B, C:Single ): IntBool;
Descriptionsimple versions: Yi = lb( Xi )
expanded versions: Yi = C * lb( A*Xi+B )
The binary logarithm (to the basis 2) is calculated.
Error handlingReal versions: DOMAIN errors occur in the case of negative Xi (including −0.0), with NAN ("not-a-number") as the default result. SING errors occur for Xi= +0.0 and yield a result of -HUGE_VAL. In the complex version, numbers with an imaginary part of zero are always treated as real numbers; therefore, an argument {0, 0} is treated as a real 0, causing a SING error with the default result {-HUGE_VAL, 0}.
Return valueFALSE (0), if no error occurred, otherwise TRUE (non-zero)
See alsoVF_pow2,   VF_log,   VF_log10,   VF_pow,   log2 (the latter function is neither defined in ANSI C nor in Pascal/Delphi, but an addition contained in <xmath.h> or in the unit XMATH).

VectorLib Table of Contents  OptiVec home