SPfQuantU

Routine

int SPfQuantU (double x, const float Xq[], int Nreg)

Purpose

Binary search for a bounding interval

Description

The index value takes on values from 0 to Nreg-1. If Nreg is equal to one, the index is set to zero. Otherwise, the index is determined as shown in the following table. The number of decision levels is one less than the number of regions.

  index           input value
   0                   x <= Xq[0]
   1           Xq[0] < x <= Xq[1]
   2           Xq[1] < x <= Xq[2]
  ...                 ...
   i         Xq[i-1] < x <= Xq[i]
  ...                 ...
 Nreg-2   Xq[Nreg-3] < x <= Xq[Nreg-2]
 Nreg-1   Xq[Nreg-2] < x

Parameters

<- int SPfQuantU

Output index of the quantizer region containing the input value x. The index takes on values from 0 to Nreg-1.

-> double x

Value to be quantized

-> const float Xq[]

Array of Nreg-1 quantizer decision levels which delimit the Nreg quantizer regions. These levels must be in ascending order.

-> int Nreg

Number of quantizer regions

Author / revision