Signal Processing Toolbox Release Notes |

Signal Processing Toolbox 5.0 Release Notes

**New Features**

This section introduces the new features and enhancements added in the Signal Processing Toolbox 5.0 since the Signal Processing Toolbox 4.3 (Release 11.1).

The Signal Processing Toolbox 5.0 provides a number of important enhancements, and a completely new facility for designing and analyzing filters, the Filter Design & Analysis Tool (FDATool).

This section is organized into the following subsections:

- Filter Design & Analysis Tool (FDATool)
- SPTool
- Spectrogram Demo
- Automatic Order Adjustment in FIR Filter Functions
- grpdelay
- hilbert
- lpc
- xcorr

**Filter Design & Analysis Tool (FDATool)**

The Filter Design & Analysis Tool provides a simple and intuitive graphical interface to most of the Signal Processing Toolbox's digital filter design functions.

To start the tool, type `fdatool at the MATLAB command line.`

**SPTool**

SPTool has received a number of enhancements:

- The Signal Browser can now play a selected portion of a signal.
- The markers (rulers) have been enhanced in all component tools (Signal Browser, Filter Viewer, Filter Designer, and Spectrum Viewer).
- The toolbars have been enhanced in all component tools. (The new Signal Browser interface is shown below.)

To start the tool, type `sptool at the MATLAB command line.`

**Spectrogram Demo**

The Spectrogram Demo (`specgramdemo(y,Fs)`

) is a new demo that displays a spectrogram, a time plot, and a frequency slice of an input signal, *y*, assuming a sample rate of *Fs* Hz.

**Automatic Order Adjustment in FIR Filter Functions**

Most of the FIR filter functions (`fir1`

, `fir2`

, `firls`

, `remez`

, `fircls`

, `fircls1`

) now automatically increase the order of linear phase filters by 1 when necessary to meet the design specifications. For example, a Type II (odd order, symmetric) linear phase filter must have a zero at radians. If a gain other than zero is instead specified at radians in any of the above mentioned functions, the function adds 1 to the filter order and proceeds to design the higher order filter.

A warning message is produced in the command window whenever a function automatically changes the filter order.

**grpdelay**

The `grpdelay`

function now returns more accurate results for IIR filters.

**hilbert**

The `hilbert`

function no longer zero-pads sequences that have a non-power-of-two length, so the transforms are now exact.

**lpc**

The `lpc`

function can now return an estimate of the prediction error variance (power) as a second output.

**xcorr**

The `xcorr`

function can now efficiently compute the cross-correlation and autocorrelation of large vectors.

Known Software Problem | Major Bug Fixes |