Filter Design Toolbox

quantize

Apply a quantizer to data

Syntax

• y = quantize(q, x)
  [y1,y2,...] = quantize(q,x1,x2,...)
  

Description

y = quantize(q, x) uses the quantizer q to quantize x. When x is a numeric array, each element of x is quantized. When x is a cell array, each numeric element of the cell array is quantized. When x is a structure, each numeric field of x is quantized. Nonnumeric elements or fields of x are left unchanged and quantize does not issue warnings for nonnumeric values.

[y1,y2,...] = quantize(q,x1,x2,...) is equivalent to y1 = quantize(q,x1), y2 = quantize(q,x2),...

The quantizer states

•  'max'         - Maximum value before quantizing
   'min'         - Minimum value before quantizing
   'noverflows'  - Number of overflows
   'nunderflows' - Number of underflows
   'noperations' - Number of quantization operations
  

are updated during the call to quantize, and running totals are kept until a call to reset is made.

Examples

The following examples demonstrate using quantize to quantize data.

Example 1 - Custom Precision Floating-Point

The code listed here produces the plot shown in the following figure.

• u=linspace(-15,15,1000); 
  q=quantizer([6 3],'float'); 
  range(q) 
   ans = 
     -14    14 
  y=quantize(q,u); 
  plot(u,y);title(tostring(q))
  
   
  

Example 2 - Fixed-Point

The code listed here produces the plot shown in the following figure.

• u=linspace(-15,15,1000); 
  q=quantizer([6 2],'wrap'); 
  range(q) 
   ans = 
     -8.0000    7.7500 
  y=quantize(q,u); 
  plot(u,y);title(tostring(q)) 
  
  
  

See Also
quantizer, set

qreport

quantizer