Filter Design Toolbox

qreport

Display the results of applying a quantizer, quantized FFT or quantized filter to data

Syntax

• qreport(obj)
  

s = qreport (obj)

where obj is one of the following objects:

• Quantizer
• Quantized filter
• Quantized FFT

Description

qreport(obj) displays the minimum (Min), maximum (Max), number of overflows (NOver), and underflows (NUnder) of the most recent application of obj to a data set, where obj is a quantized filter or a quantized FFT. Each section of quantized filter Hq or stage of quantized FFT F is represented by one line of information in the report.

Setting warning to ON displays this report when a quantized filter or quantized FFT overflows.

s = qreport(obj) returns a MATLAB structure containing the information.

Also, qreport(s) displays the report for the structure s.

Examples

Display the results of filtering a data set with a quantized filter Hq.

• [b,a] = butter(6,.5);
  Hq = sos(qfilt('ReferenceCoefficients',{b,a}));
  Y = filter(Hq,rand(50,1));
  qreport(Hq)
  
                    Max            Min         NOverflows NUnderflows NOperations
   Coefficient              1    -5.169e-016              0              1              6
                            1     -1.11e-016              0              1              6
                            1    -8.326e-017              0              1              6
         Input         0.9501       0.009861              0              0             50
        Output         0.9555        0.02808              0              0             50
  Multiplicand         0.9501      0.0006161              0              0            400
                        0.394        0.02808              0              0            350
                       0.9556        0.02808              0              0            350
       Product          0.394      -0.001708              0              0            400
                       0.6424       -0.05511              0              0            350
                       0.9556        -0.5626              0              0            350
           Sum        0.09852     -0.0007188              0              0            250
                       0.3212      -0.003827              0              0            250
                       0.9555        -0.2523              0              0            250
  

Display the results of running qfft F on a set of random data.

• F = qfft('length',64,'scale',1/64);
  Y = fft(F,rand(64,1));
  qreport(F)
  
                   Max            Min       NOverflows    NUnderflows NOperations
   Coefficient              1             -1              6              5            126
         Input         0.9883        0.01176              0              0             64
        Output         0.5364       -0.06312              0              0            128
  Multiplicand         0.9883       -0.03622              0              0           1536
       Product         0.2902       -0.02877              0              0            768
           Sum         0.5364       -0.06312              0              0           1920
  

See Also
disp, get

qfilt2tf

quantize