function sr = dm2sr(A,B,C,D,E,T);
% sr = dm2sr(A,B,C,D,E,T);
% Descriptor matrix to impulse response.
% NB At the moment - this assumes that E is unity .....
% A,B,C,D,E - descriptor matrices
% T vector of time points

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


[N,M] = size(T);
if M>N
  T = T';
  N = M;
end;

[Ny,Nu] = size(D);
NN=Ny*Nu;

[N_y,N_x] = size(C);
one = eye(N_x);

sr = zeros(N,NN);
i = 0;
for t = T'
  i=i+1;
  sr(i,:) = reshape(C*(1-exp(A*t))*B + D*ones(size(t)), 1,NN);
end;

#! /bin/sh

     ###################################### 
     ##### Model Transformation Tools #####
     ######################################

# Bourne shell script: dm2sr

# Transforms descriptor matrix rep to step response


# Copyright (c) P.J.Gawthrop, 1996.

###############################################################
## Version control history
###############################################################
## $Id$
## $Log$
###############################################################

echo Creating $1_sr.dat

$MATRIX << EOF | awk '$1 !~ /[A-Za-z]/ && NF>0 {print} '  >$1_sr.dat

  tmax=2; tstep=tmax/100;
  T = [0:tstep:tmax]';
  [A,B,C,D,E] = $1_dm($1_numpar);
  y = dm2sr(A,B,C,D,E,T);

  [Ny,Nu]=size(D);
  NN = Ny*Nu;

  xy = [T y(:,1)];
  for i=2:NN
    xy = [xy T y(:,i)];
  end;
xy

EOF