Quantizing Data with quantizer Objects

You construct a quantizer object to specify the quantization parameters to use when you quantize data sets. You can use the quantize function to quantize data according to a quantizer object's specifications.

Once you quantize data with a quantizer object, its state values might change.

The following example shows

• How you use quantize to quantize data

• How quantization affects quantizer object states

• How you reset quantizer object states to their default values using reset

1. Construct an example data set and a quantizer object.

   format long g
   rng(0,'twister');
   x = rng(100);
   q = quantizer([16,14]);

2. Retrieve the values of the maxlog and noverflows states.

   q.maxlog

   ans =
   
       -1.79769313486232e+308

   q.noverflows

   ans =
   
        0

   Note that maxlog is equal to -realmax, which indicates that the quantizer q is in a reset state.

3. Quantize the data set according to the specifications of the quantizer object.

   y = quantize(q,x);

   Warning: 625 overflow(s) occurred in the fi quantize operation.

4. Check the values of maxlog and noverflows.

   q.maxlog

   ans =
   
             1.99993896484375

   q.noverflows

   ans =
   
      625

   Note that the maximum logged value was taken after quantization, that is, q.maxlog == max(y).

5. Reset the quantizer states and check them.

   reset(q)
   q.maxlog

   ans =
   
       -1.79769313486232e+308

   q.noverflows

   ans =
   
        0