% Release Notes for the Control System Toolbox.
% Version 4.2   04-Sep-1998
%
% This file contains a list of enhancements and new features in the
% Control System Toolbox since version 4.2.  
%
% NEW FEATURES
%
%   "Symbolic" specification of transfer functions - 
%      To create the transfer function H(s) = (s+2)/(s^2+3s+1),
%      you can now directly type
%         s = tf('s')   % Laplace variable s
%         H = (s+2)/(s^2+3*s+1)
%      The same applies to ZPK models.
%
%   Frequency Response Data (FRD) object - This new addition to the
%      LTI object family provides a convenient way to manipulate and 
%      analyze frequency response functions and experimental frequency 
%      response data.
%
%   Arrays of LTI models - LTI arrays allow you to manipulate a  
%      collection of TF, SS, ZPK, or FRD models as a single MATLAB   
%      variable.  LTI arrays are an extension of single LTI models
%      that enable batch analysis of entire sets of models.  Most
%      operations and functions support LTI arrays and are applied 
%      to each model in the array in a vectorized fashion.
%
%   Extensive support of time delays - You can now specify independent 
%      time delays for each I/O pair of a MIMO model using the 
%      "ioDelayMatrix" property.  You can also use the "InputDelay" and
%      "OuputDelay" properties to specify only input or output delays 
%      (useful for state-space models).  In addition, time delays are 
%      now fully supported for discrete-time models as long as they are 
%      integer multiples of the sampling time.  The property "Td" is 
%      grandfathered and superseded by "InputDelay."
%
%   Improved algorithm for minimal state-space realization computation - 
%      The MINREAL command uses a new, more robust algorithm.  You can
%      also use the new command SMINREAL to remove states that are not
%      connected to the input(s) or output(s).
%         
%   New LTI properties "InputGroup" and "OutputGroup" - 
%      These properties allow you to specify different categories
%      (groups) of input or output channels, and to attach names to
%      these groups.  For instance, you can group the inputs 1 and 3
%      into a group labeled 'noise'.  You can then refer collectively
%      to these input channels by the name 'noise', as in 
%         sys(:,'noise')
%
% ENHANCEMENTS
%
%   LTI Viewer Version 2 -
%      The new LTI Viewer allows you to analyze up to six different 
%      response plots on a single Viewer. Each response contains its
%      own set of Viewer Controls, accessed by right-clicking in any
%      response axes. The Viewer Configuration tool, available from
%      the Viewer's Tools menu, allows you to change the number 
%      and type of responses contained in the Viewer.
%
%   Simulink LTI Viewer - 
%      The Simulink LTI Viewer can now linearize Simulink models
%      containing discrete states. The linearization routine generates
%      a discrete LTI object with a sample time which is the least 
%      common multiple of all the sample times in the Simulink model.
%      In addition, the Input and Output Point blocks can now be dropped
%      on vectorized signal lines in the Simulink diagram.
%      
%
% ----------------------------------------------------------------------
% README file for the Control System Toolbox.
% Version 4.1   05-Dec-1997
%
% This file contains a list of enhancements and new features in the
% Control System Toolbox since version 4.0.  
%
% NEW FEATURES
%
%   RLTOOL - Graphical user interface (GUI) for Root Locus Design.
%
%   Simulink LTI Viewer - Linear analysis tool for Simulink diagrams.
%      To open this tool, select Linear Analysis in the Tools menu
%      of your Simulink diagram.
%
% ENHANCEMENTS
%
%   1) Sharper root locus plots
%   2) Export option in the LTI Viewer
%
% ----------------------------------------------------------------------
% README file for the Control System Toolbox.
% Version 4.0  15-Nov-1996
% 
% NEW FEATURES
% 
%   LTI objects - specialized data structures to represent transfer 
%      functions, zero-pole-gain models, or state-space models.
%      See the HELP for TF, ZPK, SS, and LTIPROPS for more details.
%
%   Overloaded operations on LTI objects - you can now use +, *, [],...
%      to manipulate and interconnect LTI models.
%   
%   LTIVIEW - graphical user interface for linear system analysis.
%
%   STEP, BODE, ... - now handle MIMO system responses and allow you
%      to compare the responses of several systems.
%
%   CARE, DARE - enhanced continuous and discrete Riccati equation 
%      solvers.
%
%   KALMAN - Kalman estimator synthesis.
%
%   MILLDEMO - new demonstration of LQG synthesis tools.
%
% Use HELP on these files or TYPE them for more information.

%   Copyright (c) 1986-1999 The Mathworks, Inc. All Rights Reserved.
% $Revision: 1.8 $


  
