changeset 3502:b5238ac1dca9

[project @ 2000-01-31 07:40:53 by jwe]
author jwe
date Mon, 31 Jan 2000 07:41:01 +0000
parents 8b21bcbc1080
children d14c483b3c12
files scripts/control/base/bode.m scripts/control/base/ctrb.m scripts/control/base/damp.m scripts/control/base/dcgain.m scripts/control/base/dlyap.m scripts/control/base/dre.m scripts/control/base/lqg.m scripts/control/base/ltifr.m scripts/control/base/nyquist.m scripts/control/base/place.m scripts/control/hinf/h2syn.m scripts/control/hinf/hinf_ctr.m scripts/control/hinf/hinfsyn.m scripts/control/hinf/hinfsyn_chk.m scripts/control/hinf/hinfsyn_ric.m scripts/control/hinf/is_dgkf.m scripts/control/obsolete/qzval.m scripts/control/system/buildssic.m scripts/control/system/c2d.m scripts/control/system/d2c.m scripts/control/system/dmr2d.m scripts/control/system/is_controllable.m scripts/control/system/is_detectable.m scripts/control/system/is_observable.m scripts/control/system/is_sample.m scripts/control/system/is_stabilizable.m scripts/control/system/parallel.m scripts/control/system/ss2sys.m scripts/control/system/sysadd.m scripts/control/system/sysappend.m scripts/control/system/syscont.m scripts/control/system/sysdisc.m scripts/control/system/sysdup.m scripts/control/system/sysgroup.m scripts/control/system/sysmult.m scripts/control/system/sysprune.m scripts/control/system/syssub.m scripts/control/system/zp2ss.m scripts/control/util/__zgpbal__.m scripts/control/util/zgfmul.m scripts/control/util/zgreduce.m
diffstat 41 files changed, 172 insertions(+), 174 deletions(-) [+]
line wrap: on
line diff
--- a/scripts/control/base/bode.m
+++ b/scripts/control/base/bode.m
@@ -34,7 +34,7 @@
 ##
 ## if @var{sys} is discrete, then bode evaluates G(@code{exp}(jwT)), where
 ## @itemize @bullet
-## @item @var{T}=@code{sysgettsam(@var{sys})} (the system sampling time) and
+## @item @math{T} is the system sampling time
 ## @item @math{G(z)} is the system transfer function.
 ## @end itemize
 ##
--- a/scripts/control/base/ctrb.m
+++ b/scripts/control/base/ctrb.m
@@ -18,14 +18,14 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} ctrb (@var{sys}, @var{b})
-## @deftypefnx {Function File} {} ctrb (@var{A}, @var{B})
+## @deftypefnx {Function File} {} ctrb (@var{a}, @var{b})
 ## Build controllability matrix
 ## @example
 ##              2       n-1
 ## Qs = [ B AB A B ... A   B ]
 ## @end example
 ##
-## of a system data structure or the pair (@var{A}, @var{B}).
+## of a system data structure or the pair (@var{a}, @var{b}).
 ##
 ## @strong{Note} @code{ctrb} forms the controllability matrix.
 ## The numerical properties of @code{is_controllable}
--- a/scripts/control/base/damp.m
+++ b/scripts/control/base/damp.m
@@ -19,7 +19,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} damp (@var{p}, @var{tsam})
 ## Displays eigenvalues, natural frequencies and damping ratios
-## of the eigenvalues of a matrix @var{p} or the @var{A}-matrix of a
+## of the eigenvalues of a matrix @var{p} or the @math{A}-matrix of a
 ## system @var{p}, respectively.
 ## If @var{p} is a system, @var{tsam} must not be specified.
 ## If @var{p} is a matrix and @var{tsam} is specified, eigenvalues
--- a/scripts/control/base/dcgain.m
+++ b/scripts/control/base/dcgain.m
@@ -17,11 +17,11 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} dcgain (@var{sys}, tol)
+## @deftypefn {Function File} {} dcgain (@var{sys}, @var{tol})
 ## Returns dc-gain matrix. If dc-gain is infinite
 ## an empty matrix is returned.
 ## The argument @var{tol} is an optional tolerance for the condition
-## number of @var{A}-Matrix in @var{sys} (default @var{tol} = 1.0e-10)
+## number of the @math{A}-Matrix in @var{sys} (default @var{tol} = 1.0e-10)
 ## @end deftypefn
 
 ## Author: Kai P. Mueller <mueller@ifr.ing.tu-bs.de>
--- a/scripts/control/base/dlyap.m
+++ b/scripts/control/base/dlyap.m
@@ -48,8 +48,7 @@
 ##
 ## @strong{Method}
 ## Uses Schur decomposition method as in Kitagawa,
-## @cite{An Algorithm for Solving the Matrix Equation @var{X} =
-## @var{F}@var{X}@var{F}' + @var{S}},
+## @cite{An Algorithm for Solving the Matrix Equation @math{X = F X F' + S}},
 ## International Journal of Control, Volume 25, Number 5, pages 745--753
 ## (1977).
 ##
--- a/scripts/control/base/dre.m
+++ b/scripts/control/base/dre.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{tvals}, @var{Plist}] =} dre (@var{sys}, @var{Q}, @var{R}, @var{Qf}, @var{t0}, @var{tf}[, @var{Ptol}, @var{maxits}]);
+## @deftypefn {Function File} {[@var{tvals}, @var{plist}] =} dre (@var{sys}, @var{q}, @var{r}, @var{qf}, @var{t0}, @var{tf}, @var{ptol}, @var{maxits});
 ## Solve the differential Riccati equation
 ## @ifinfo
 ## @example
@@ -58,16 +58,16 @@
 ## @table @var
 ## @item sys
 ## continuous time system data structure
-## @item Q
+## @item q
 ## state integral penalty
-## @item R
+## @item r
 ## input integral penalty
-## @item Qf
+## @item qf
 ## state terminal penalty
 ## @item t0
 ## @itemx tf
 ## limits on the integral
-## @item Ptol
+## @item ptol
 ## tolerance (used to select time samples; see below); default = 0.1
 ## @item maxits
 ## number of refinement iterations (default=10)
@@ -75,10 +75,10 @@
 ## @strong{Outputs}
 ## @table @var
 ## @item tvals
-## time values at which @var{P}(@var{t}) is computed
-## @item Plist
-## list values of @var{P}(@var{t}); nth (@var{Plist}, @var{ii})
-## is @var{P}(@var{tvals}(@var{ii})).
+## time values at which @var{p}(@var{t}) is computed
+## @item plist
+## list values of @var{p}(@var{t}); nth (@var{plist}, @var{ii})
+## is @var{p}(@var{tvals}(@var{ii})).
 ##
 ## @item tvals
 ## @example
--- a/scripts/control/base/lqg.m
+++ b/scripts/control/base/lqg.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{K}, @var{Q}, @var{P}, @var{Ee}, @var{Er}] =} lqg (@var{sys}, @var{Sigw}, @var{Sigv}, @var{Q}, @var{R}, @var{in_idx})
+## @deftypefn {Function File} {[@var{k}, @var{q1}, @var{p1}, @var{ee}, @var{er}] =} lqg (@var{sys}, @var{sigw}, @var{sigv}, @var{q}, @var{r}, @var{in_idx})
 ## Design a linear-quadratic-gaussian optimal controller for the system
 ## @example
 ## dx/dt = A x + B u + G w       [w]=N(0,[Sigw 0    ])
@@ -33,11 +33,11 @@
 ## @table @var
 ## @item  sys
 ## system data structure
-## @item  Sigw
-## @itemx  Sigv
+## @item  sigw
+## @itemx  sigv
 ## intensities of independent Gaussian noise processes (as above)
-## @item  Q
-## @itemx  R
+## @item  q
+## @itemx  r
 ## state, control weighting respectively.  Control ARE is
 ## @item  in_idx
 ## names or indices of controlled inputs (see @code{sysidx}, @code{listidx})
@@ -47,17 +47,17 @@
 ## @end table
 ## @strong{Outputs}
 ## @table @var
-## @item    K
+## @item    k
 ## system data structure format LQG optimal controller (Obtain A,B,C
 ## matrices with @code{sys2ss}, @code{sys2tf}, or @code{sys2zp} as
 ## appropriate)
-## @item    P
+## @item    p1
 ## Solution of control (state feedback) algebraic Riccati equation
-## @item    Q
+## @item    q1
 ## Solution of estimation algebraic Riccati equation
-## @item    Ee
+## @item    ee
 ## estimator poles
-## @item    Es
+## @item    es
 ## controller poles
 ## @end table
 ## @end deftypefn
--- a/scripts/control/base/ltifr.m
+++ b/scripts/control/base/ltifr.m
@@ -17,13 +17,13 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} ltifr (@var{A}, @var{B}, @var{w})
+## @deftypefn {Function File} {} ltifr (@var{a}, @var{b}, @var{w})
 ## @deftypefnx {Function File} {} ltifr (@var{sys}, @var{w})
 ## Linear time invariant frequency response of single input systems
 ## @strong{Inputs}
 ## @table @var
-## @item A
-## @itemx B
+## @item a
+## @itemx b
 ## coefficient matrices of @math{dx/dt = A x + B u}
 ## @item sys
 ## system data structure
--- a/scripts/control/base/nyquist.m
+++ b/scripts/control/base/nyquist.m
@@ -32,7 +32,7 @@
 ## frequency values for evaluation.
 ## if sys is continuous, then bode evaluates @math{G(jw)}
 ## if sys is discrete, then bode evaluates @math{G(exp(jwT))}, where
-## @math{@var{T}=sysgettsam(@var{sys})} (the system sampling time)
+## @math{T} is the system sampling time.
 ## @item default
 ## the default frequency range is selected as follows: (These
 ## steps are NOT performed if @var{w} is specified)
--- a/scripts/control/base/place.m
+++ b/scripts/control/base/place.m
@@ -17,10 +17,10 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} place (@var{sys}, @var{P})
+## @deftypefn {Function File} {} place (@var{sys}, @var{p})
 ## Computes the matrix  K such that if the state
 ## is feedback with gain K, then the eigenvalues  of the closed loop
-## system (i.e. A-BK) are those specified in the vector P.
+## system (i.e. A-BK) are those specified in the vector @var{p}.
 ##
 ## Version: Beta (May-1997): If you have any comments, please let me know.
 ## (see the file place.m for my address)
--- a/scripts/control/hinf/h2syn.m
+++ b/scripts/control/hinf/h2syn.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[K}, @var{gain}, @var{Kc}, @var{Kf}, @var{Pc}, @var{Pf}] = h2syn (@var{Asys}, @var{nu}, @var{ny}, @var{tol})
+## @deftypefn {Function File} {[K}, @var{gain}, @var{kc}, @var{kf}, @var{pc}, @var{pf}] = h2syn (@var{asys}, @var{nu}, @var{ny}, @var{tol})
 ## Design H2 optimal controller per procedure in
 ## Doyle, Glover, Khargonekar, Francis, "State Space Solutions to Standard
 ## H2 and Hinf Control Problems", IEEE TAC August 1989
@@ -27,7 +27,7 @@
 ##
 ## @strong{Inputs} input system is passed as either
 ## @table @var
-## @item Asys
+## @item asys
 ## system data structure (see ss2sys, sys2ss)
 ## @itemize @bullet
 ## @item controller is implemented for continuous time systems
@@ -43,17 +43,17 @@
 ##
 ## @strong{Outputs}
 ## @table @var
-## @item    K
+## @item    k
 ## system controller
 ## @item    gain
 ## optimal closed loop gain
-## @item    Kc
+## @item    kc
 ## full information control (packed)
-## @item    Kf
+## @item    kf
 ## state estimator (packed)
-## @item    Pc
+## @item    pc
 ## ARE solution matrix for regulator subproblem
-## @item    Pf
+## @item    pf
 ## ARE solution matrix for filter subproblem
 ## @end table
 ## @end deftypefn
--- a/scripts/control/hinf/hinf_ctr.m
+++ b/scripts/control/hinf/hinf_ctr.m
@@ -17,21 +17,21 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} hinf_ctr (@var{dgs}, @var{F}, @var{H}, @var{Z}, @var{g})
+## @deftypefn {Function File} {} hinf_ctr (@var{dgs}, @var{f}, @var{h}, @var{z}, @var{g})
 ## Called by @code{hinfsyn} to compute the H_inf optimal controller.
 ##
 ## @strong{Inputs}
 ## @table @var
 ## @item dgs
 ## data structure returned by @code{is_dgkf}
-## @item F
-## @itemx H
+## @item f
+## @itemx h
 ## feedback and filter gain (not partitioned)
 ## @item g
 ## final gamma value
 ## @end table
 ## @strong{Outputs}
-## controller K (system data structure)
+## controller (system data structure)
 ##
 ## Do not attempt to use this at home; no argument checking performed.
 ## @end deftypefn
--- a/scripts/control/hinf/hinfsyn.m
+++ b/scripts/control/hinf/hinfsyn.m
@@ -17,11 +17,11 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{K}, @var{g}, @var{GW}, @var{Xinf}, @var{Yinf}] =} hinfsyn (@var{Asys}, @var{nu}, @var{ny}, @var{gmin}, @var{gmax}, @var{gtol}, @var{ptol}, @var{tol})
+## @deftypefn {Function File} {[@var{k}, @var{g}, @var{gw}, @var{xinf}, @var{yinf}] =} hinfsyn (@var{asys}, @var{nu}, @var{ny}, @var{gmin}, @var{gmax}, @var{gtol}, @var{ptol}, @var{tol})
 ##
 ## @strong{Inputs} input system is passed as either
 ## @table @var
-## @item Asys
+## @item asys
 ## system data structure (see ss2sys, sys2ss)
 ## @itemize @bullet
 ## @item controller is implemented for continuous time systems
@@ -49,15 +49,15 @@
 ## @end table
 ## @strong{Outputs}
 ## @table @var
-## @item K
+## @item k
 ## system controller
 ## @item g
 ## designed gain value
-## @item GW
+## @item gw
 ## closed loop system
-## @item Xinf
+## @item xinf
 ## ARE solution matrix for regulator subproblem
-## @item Yinf
+## @item yinf
 ## ARE solution matrix for filter subproblem
 ## @end table
 ##
--- a/scripts/control/hinf/hinfsyn_chk.m
+++ b/scripts/control/hinf/hinfsyn_chk.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{Pc}, @var{Pf}] =} hinfsyn_chk (@var{A}, @var{B1}, @var{B2}, @var{C1}, @var{C2}, @var{D12}, @var{D21}, @var{g}, @var{ptol})
+## @deftypefn {Function File} {[@var{retval}, @var{pc}, @var{pf}] =} hinfsyn_chk (@var{a}, @var{b1}, @var{b2}, @var{c1}, @var{c2}, @var{d12}, @var{d21}, @var{g}, @var{ptol})
 ## Called by @code{hinfsyn} to see if gain @var{g} satisfies conditions in
 ## Theorem 3 of
 ## Doyle, Glover, Khargonekar, Francis, "State Space Solutions to Standard
@@ -38,9 +38,9 @@
 ## @table @var
 ## @item retval
 ##  1 if g exceeds optimal Hinf closed loop gain, else 0
-## @item Pc
+## @item pc
 ##  solution of "regulator" H-inf ARE
-## @item Pf
+## @item pf
 ##  solution of "filter" H-inf ARE
 ## @end table
 ## Do not attempt to use this at home; no argument checking performed.
--- a/scripts/control/hinf/hinfsyn_ric.m
+++ b/scripts/control/hinf/hinfsyn_ric.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{Xinf}, @var{x_ha_err}] =} hinfsyn_ric (@var{A}, @var{BB}, @var{C1}, @var{d1dot}, @var{R}, @var{ptol})
+## @deftypefn {Function File} {[@var{xinf}, @var{x_ha_err}] =} hinfsyn_ric (@var{a}, @var{bb}, @var{c1}, @var{d1dot}, @var{r}, @var{ptol})
 ## Forms
 ## @example
 ## xx = ([BB; -C1'*d1dot]/R) * [d1dot'*C1 BB'];
@@ -30,17 +30,17 @@
 ## @item 0
 ## successful
 ## @item 1
-## Xinf has imaginary eigenvalues
+## @var{xinf} has imaginary eigenvalues
 ## @item 2
-## Hx not Hamiltonian
+## @var{hx} not Hamiltonian
 ## @item 3
-## Xinf has inf. eigenvalues (numerical overflow)
+## @var{xinf} has infinite eigenvalues (numerical overflow)
 ## @item 4
-## Xinf not symmetric
+## @var{xinf} not symmetric
 ## @item 5
-## Xinf not positive definite
+## @var{xinf} not positive definite
 ## @item 6
-## R is singular
+## @var{r} is singular
 ## @end table
 ## @end deftypefn
 
--- a/scripts/control/hinf/is_dgkf.m
+++ b/scripts/control/hinf/is_dgkf.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{dgkf_struct} ] =} is_dgkf (@var{Asys}, @var{nu}, @var{ny}, @var{tol} )
+## @deftypefn {Function File} {[@var{retval}, @var{dgkf_struct} ] =} is_dgkf (@var{asys}, @var{nu}, @var{ny}, @var{tol} )
 ## Determine whether a continuous time state space system meets
 ## assumptions of DGKF algorithm.
 ## Partitions system into:
@@ -27,14 +27,14 @@
 ## [ y   ]   [Cy | Dyw Dyu ]
 ## @end example
 ## or similar discrete-time system.
-## If necessary, orthogonal transformations @var{Qw}, @var{Qz} and nonsingular
-## transformations @var{Ru}, @var{Ry} are applied to respective vectors
+## If necessary, orthogonal transformations @var{qw}, @var{qz} and nonsingular
+## transformations @var{ru}, @var{ry} are applied to respective vectors
 ## @var{w}, @var{z}, @var{u}, @var{y} in order to satisfy DGKF assumptions.
-## Loop shifting is used if @var{Dyu} block is nonzero.
+## Loop shifting is used if @var{dyu} block is nonzero.
 ##
 ## @strong{Inputs}
 ## @table @var
-## @item         Asys
+## @item         asys
 ## system data structure
 ## @item           nu
 ## number of controlled inputs
@@ -53,32 +53,32 @@
 ## @item      nw
 ## @itemx     nz
 ## dimensions of @var{w}, @var{z}
-## @item      A
-## system @var{A} matrix
-## @item      Bw
-## (@var{n} x @var{nw}) @var{Qw}-transformed disturbance input matrix
-## @item      Bu
-## (@var{n} x @var{nu}) @var{Ru}-transformed controlled input matrix;
+## @item      a
+## system @math{A} matrix
+## @item      bw
+## (@var{n} x @var{nw}) @var{qw}-transformed disturbance input matrix
+## @item      bu
+## (@var{n} x @var{nu}) @var{ru}-transformed controlled input matrix;
 ##
 ## @strong{Note} @math{B = [Bw Bu]}
-## @item      Cz
+## @item      cz
 ## (@var{nz} x @var{n}) Qz-transformed error output matrix
-## @item      Cy
-## (@var{ny} x @var{n}) @var{Ry}-transformed measured output matrix
+## @item      cy
+## (@var{ny} x @var{n}) @var{ry}-transformed measured output matrix
 ##
 ## @strong{Note} @math{C = [Cz; Cy]}
-## @item      Dzu
-## @item      Dyw
-## off-diagonal blocks of transformed @var{D} matrix that enter
+## @item      dzu
+## @item      dyw
+## off-diagonal blocks of transformed system @math{D} matrix that enter
 ## @var{z}, @var{y} from @var{u}, @var{w} respectively
-## @item      Ru
+## @item      ru
 ## controlled input transformation matrix
-## @item      Ry
+## @item      ry
 ## observed output transformation matrix
-## @item      Dyu_nz
-## nonzero if the @var{Dyu} block is nonzero.
-## @item      Dyu
-## untransformed @var{Dyu} block
+## @item      dyu_nz
+## nonzero if the @var{dyu} block is nonzero.
+## @item      dyu
+## untransformed @var{dyu} block
 ## @item      dflg
 ## nonzero if the system is discrete-time
 ## @end table
--- a/scripts/control/obsolete/qzval.m
+++ b/scripts/control/obsolete/qzval.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} qzval (@var{A}, @var{B})
+## @deftypefn {Function File} {} qzval (@var{a}, @var{b})
 ## Compute generalized eigenvalues of the matrix pencil
 ## @ifinfo
 ## @example
@@ -30,7 +30,7 @@
 ## @end tex
 ## @end iftex
 ##
-## @var{A} and @var{B} must be real matrices.
+## @var{a} and @var{b} must be real matrices.
 ##
 ## @strong{Note} @code{qzval} is obsolete; use @code{qz} instead.
 ## @end deftypefn
--- a/scripts/control/system/buildssic.m
+++ b/scripts/control/system/buildssic.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} buildssic (@var{Clst}, @var{Ulst}, @var{Olst}, @var{Ilst}, @var{s1}, @var{s2}, @var{s3}, @var{s4}, @var{s5}, @var{s6}, @var{s7}, @var{s8})
+## @deftypefn {Function File} {} buildssic (@var{clst}, @var{ulst}, @var{olst}, @var{ilst}, @var{s1}, @var{s2}, @var{s3}, @var{s4}, @var{s5}, @var{s6}, @var{s7}, @var{s8})
 ##
 ## Form an arbitrary complex (open or closed loop) system in
 ## state-space form from several systems. "@code{buildssic}" can
@@ -36,7 +36,7 @@
 ## outputs and inputs and up to 8 systems s1-s8.
 ## Format of the lists:
 ## @table @var
-## @item      Clst
+## @item      clst
 ## connection list, describes the input signal of
 ## each system. The maximum number of rows of Clst is
 ## equal to the sum of all inputs of s1-s8.
@@ -46,20 +46,20 @@
 ## + output 2 - output 1, new input 2 is old input 2
 ## + output 1. The order of rows is arbitrary.
 ##
-## @item     Ulst
+## @item     ulst
 ## if not empty the old inputs in vector Ulst will
 ## be appended to the outputs. You need this if you
 ## want to "pull out" the input of a system. Elements
 ## are input numbers of s1-s8.
 ##
-## @item     Olst
+## @item     olst
 ## output list, specifiy the outputs of the resulting
 ## systems. Elements are output numbers of s1-s8.
 ## The numbers are alowed to be negative and may
 ## appear in any order. An empty matrix means
 ## all outputs.
 ##
-## @item     Ilst
+## @item     ilst
 ## input list, specifiy the inputs of the resulting
 ## systems. Elements are input numbers of s1-s8.
 ## The numbers are alowed to be negative and may
@@ -87,14 +87,14 @@
 ## GW = buildssic([1 2; 2 -1], 2, [1 2 3], 2, G, K);
 ## @end example
 ## @table @var
-## @item Clst
+## @item clst
 ## (1. row) connect input 1 (G) with output 2 (K).
 ## (2. row) connect input 2 (K) with neg. output 1 (G).
-## @item Ulst
+## @item ulst
 ## append input of (2) K to the number of outputs.
-## @item Olst
+## @item olst
 ## Outputs are output of 1 (G), 2 (K) and appended output 3 (from Ulst).
-## @item Ilst
+## @item ilst
 ## the only input is 2 (K).
 ## @end table
 ##
--- a/scripts/control/system/c2d.m
+++ b/scripts/control/system/c2d.m
@@ -17,8 +17,8 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} c2d (@var{sys}, @var{opt}, @var{T})
-## @deftypefnx {Function File} {} c2d (@var{sys}, @var{T})
+## @deftypefn {Function File} {} c2d (@var{sys}, @var{opt}, @var{t})
+## @deftypefnx {Function File} {} c2d (@var{sys}, @var{t})
 ##
 ## @strong{Inputs}
 ## @table @var
@@ -41,16 +41,16 @@
 ## @end example
 ## FIXME: This option exits with an error if @var{sys} is not purely
 ## continuous. (The @code{ex} option can handle mixed systems.)
-## @item @var{T}
+## @item t
 ## sampling time; required if sys is purely continuous.
 ##
 ## @strong{Note} If the 2nd argument is not a string, @code{c2d} assumes that
-## the 2nd argument is @var{T} and performs appropriate argument checks.
+## the 2nd argument is @var{t} and performs appropriate argument checks.
 ## @end table
 ##
 ## @strong{Outputs}
 ## @var{dsys} discrete time equivalent via zero-order hold,
-## sample each @var{T} sec.
+## sample each @var{t} sec.
 ##
 ## converts the system data structure describing
 ## @example
--- a/scripts/control/system/d2c.m
+++ b/scripts/control/system/d2c.m
@@ -36,14 +36,14 @@
 ## (default) Conversion is performed via a matrix logarithm.
 ## Due to some problems with this computation, it is
 ## followed by a steepest descent algorithm to identify continuous time
-## @var{A}, @var{B}, to get a better fit to the original data.
+## @var{a}, @var{b}, to get a better fit to the original data.
 ##
 ## If called as @code{d2c (@var{sys}, @var{tol})}, with @var{tol}
 ## positive scalar, the @code{"log"} option is used.  The default value
 ## for @var{tol} is @code{1e-8}.
 ## @item        "bi"
 ## Conversion is performed via bilinear transform
-## @math{z = (1 + s T / 2)/(1 - s T / 2)} where @var{T} is the
+## @math{z = (1 + s T / 2)/(1 - s T / 2)} where @math{T} is the
 ## system sampling time (see @code{sysgettsam}).
 ##
 ## FIXME: bilinear option exits with an error if @var{sys} is not purely
--- a/scripts/control/system/dmr2d.m
+++ b/scripts/control/system/dmr2d.m
@@ -17,10 +17,10 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{dsys}, @var{fidx}] =} dmr2d (@var{sys}, @var{idx}, @var{sprefix}, @var{Ts2}, @var{cuflg})
+## @deftypefn {Function File} {[@var{dsys}, @var{fidx}] =} dmr2d (@var{sys}, @var{idx}, @var{sprefix}, @var{ts2}, @var{cuflg})
 ## convert a multirate digital system to a single rate digital system
-## states specified by @var{idx}, @var{sprefix} are sampled at @var{Ts2}, all
-## others are assumed sampled at @var{Ts1} = @code{sysgettsam(@var{sys})}.
+## states specified by @var{idx}, @var{sprefix} are sampled at @var{ts2}, all
+## others are assumed sampled at @var{ts1} = @code{sysgettsam (@var{sys})}.
 ##
 ## @strong{Inputs}
 ## @table @var
@@ -33,14 +33,14 @@
 ## @item   sprefix
 ## list of string prefixes of states with sampling time
 ## @code{sysgettsam(@var{sys})} (may be empty)
-## @item   Ts2
+## @item   ts2
 ## sampling time of states not specified by @var{idx}, @var{sprefix}
 ## must be an integer multiple of @code{sysgettsam(@var{sys})}
 ## @item   cuflg
 ## "constant u flag" if @var{cuflg} is nonzero then the system inputs are
-## assumed to be constant over the revised sampling interval @var{Ts2}.
+## assumed to be constant over the revised sampling interval @var{ts2}.
 ## Otherwise, since the inputs can change during the interval
-## @var{t} in @math{[k Ts2, (k+1) Ts2]}, an additional set of inputs is
+## @var{t} in @math{[k ts2, (k+1) ts2]}, an additional set of inputs is
 ## included in the revised B matrix so that these intersample inputs
 ## may be included in the single-rate system.
 ## default @var{cuflg} = 1.
@@ -49,21 +49,21 @@
 ## @strong{Outputs}
 ## @table @var
 ## @item   dsys
-## equivalent discrete time system with sampling time @var{Ts2}.
+## equivalent discrete time system with sampling time @var{ts2}.
 ##
-## The sampling time of sys is updated to @var{Ts2}.
+## The sampling time of sys is updated to @var{ts2}.
 ##
 ## if @var{cuflg}=0 then a set of additional inputs is added to
 ## the system with suffixes _d1, ..., _dn to indicate their
-## delay from the starting time k @var{Ts2}, i.e.
+## delay from the starting time k @var{ts2}, i.e.
 ## u = [u_1; u_1_d1; ..., u_1_dn] where u_1_dk is the input
-## k*Ts1 units of time after u_1 is sampled. (Ts1 is
-## the original sampling time of discrete time sys and
-## @var{Ts2} = (n+1)*Ts1)
+## k*ts1 units of time after u_1 is sampled. (@var{ts1} is
+## the original sampling time of the discrete time system and
+## @var{ts2} = (n+1)*ts1)
 ##
 ## @item   fidx
 ## indices of "formerly fast" states specified by @var{idx} and @var{sprefix};
-## these states are updated to the new (slower) sampling interval @var{Ts2}.
+## these states are updated to the new (slower) sampling interval @var{ts2}.
 ## @end table
 ##
 ## @strong{WARNING} Not thoroughly tested yet; especially when
--- a/scripts/control/system/is_controllable.m
+++ b/scripts/control/system/is_controllable.m
@@ -17,8 +17,8 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{U}] =} is_controllable (@var{sys}, @var{tol})
-## @deftypefnx {Function File} {[@var{retval}, @var{U}] =} is_controllable (@var{a}, @var{b}, @var{tol})
+## @deftypefn {Function File} {[@var{retval}, @var{u}] =} is_controllable (@var{sys}, @var{tol})
+## @deftypefnx {Function File} {[@var{retval}, @var{u}] =} is_controllable (@var{a}, @var{b}, @var{tol})
 ## Logical check for system controllability.
 ##
 ## @strong{Inputs}
--- a/scripts/control/system/is_detectable.m
+++ b/scripts/control/system/is_detectable.m
@@ -17,8 +17,8 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{U}] =} is_detectable (@var{a}, @var{c}, @var{tol})
-## @deftypefnx {Function File} {[@var{retval}, @var{U}] =} is_detectable (@var{sys}, @var{tol})
+## @deftypefn {Function File} {[@var{retval}, @var{u}] =} is_detectable (@var{a}, @var{c}, @var{tol})
+## @deftypefnx {Function File} {[@var{retval}, @var{u}] =} is_detectable (@var{sys}, @var{tol})
 ## Test for detactability (observability of unstable modes) of
 ## (@var{a},@var{c}).
 ##
--- a/scripts/control/system/is_observable.m
+++ b/scripts/control/system/is_observable.m
@@ -17,8 +17,8 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{U}] =} is_observable (@var{a}, @var{c}, @var{tol})
-## @deftypefnx {Function File} {[@var{retval}, @var{U}] =} is_observable (@var{sys}, @var{tol})
+## @deftypefn {Function File} {[@var{retval}, @var{u}] =} is_observable (@var{a}, @var{c}, @var{tol})
+## @deftypefnx {Function File} {[@var{retval}, @var{u}] =} is_observable (@var{sys}, @var{tol})
 ## Logical check for system observability.
 ##
 ## Default: tol = 10*norm(a,'fro')*eps
--- a/scripts/control/system/is_sample.m
+++ b/scripts/control/system/is_sample.m
@@ -17,8 +17,8 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} is_sample (@var{Ts})
-## return true if @var{Ts} is a valid sampling time
+## @deftypefn {Function File} {} is_sample (@var{ts})
+## Return true if @var{ts} is a valid sampling time
 ## (real,scalar, > 0)
 ## @end deftypefn
 
--- a/scripts/control/system/is_stabilizable.m
+++ b/scripts/control/system/is_stabilizable.m
@@ -17,16 +17,16 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{retval}, @var{U}] =} is_stabilizable (@var{sys}, @var{tol})
-## @deftypefnx {Function File} {[@var{retval}, @var{U}] =} is_stabilizable (@var{a}, @var{b}, @var{tol})
+## @deftypefn {Function File} {[@var{retval}, @var{u}] =} is_stabilizable (@var{sys}, @var{tol})
+## @deftypefnx {Function File} {[@var{retval}, @var{u}] =} is_stabilizable (@var{a}, @var{b}, @var{tol})
 ## Logical check for system stabilizability (i.e., all unstable modes are controllable).
 ##
 ## Test for stabilizability is performed via an ordered Schur decomposition
-## that reveals the unstable subspace of the system @var{A} matrix.
+## that reveals the unstable subspace of the system @var{a} matrix.
 ##
-## Returns @code{retval} = 1 if the system, @code{a}, is stabilizable,
-## if the pair  (@code{a}, @code{b}) is stabilizable, or 0 if not.
-## @code{U} = orthogonal basis of controllable subspace.
+## Returns @code{retval} = 1 if the system, @var{a}, is stabilizable,
+## if the pair  (@var{a}, @var{b}) is stabilizable, or 0 if not.
+## @var{u} = orthogonal basis of controllable subspace.
 ##
 ## Controllable subspace is determined by applying Arnoldi iteration with
 ## complete re-orthogonalization to obtain an orthogonal basis of the
--- a/scripts/control/system/parallel.m
+++ b/scripts/control/system/parallel.m
@@ -17,18 +17,18 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} parallel (@var{Asys}, @var{Bsys})
+## @deftypefn {Function File} {} parallel (@var{asys}, @var{bsys})
 ## Forms the parallel connection of two systems.
 ##
 ##              ____________________
 ##              |      ________    |
-##     u  ----->|----> | Asys |--->|----> y1
+##     u  ----->|----> | asys |--->|----> y1
 ##         |    |      --------    |
 ##         |    |      ________    |
-##         |--->|----> | Bsys |--->|----> y2
+##         |--->|----> | bsys |--->|----> y2
 ##              |      --------    |
 ##              --------------------
-##                   Ksys
+##                   ksys
 ## @end deftypefn
 
 ## Author: David Clem
--- a/scripts/control/system/ss2sys.m
+++ b/scripts/control/system/ss2sys.m
@@ -175,7 +175,7 @@
 ##   0  0
 ##   0  0
 ## @end example
-## Notice that the @var{D} matrix is constructed  by default to the
+## Notice that the @math{D} matrix is constructed  by default to the
 ## correct dimensions.  Default input and output signals names were assigned
 ## since none were given.
 ## @end deftypefn
--- a/scripts/control/system/sysadd.m
+++ b/scripts/control/system/sysadd.m
@@ -17,23 +17,23 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {}  sysadd (@var{Gsys}, @var{Hsys})
-## returns @var{sys} = @var{Gsys} + @var{Hsys}.
+## @deftypefn {Function File} {}  sysadd (@var{gsys}, @var{hsys})
+## returns @var{sys} = @var{gsys} + @var{hsys}.
 ## @itemize @bullet
 ## @item Exits with
-## an error if @var{Gsys} and @var{Hsys} are not compatibly dimensioned.
+## an error if @var{gsys} and @var{hsys} are not compatibly dimensioned.
 ## @item Prints a warning message is system states have identical names;
 ## duplicate names are given a suffix to make them unique.
-## @item @var{sys} input/output names are taken from @var{Gsys}.
+## @item @var{sys} input/output names are taken from @var{gsys}.
 ## @end itemize
 ## @example
 ## @group
 ##           ________
-##      ----|  Gsys  |---
+##      ----|  gsys  |---
 ## u   |    ----------  +|
 ## -----                (_)----> y
 ##     |     ________   +|
-##      ----|  Hsys  |---
+##      ----|  hsys  |---
 ##           --------
 ## @end group
 ## @end example
--- a/scripts/control/system/sysappend.m
+++ b/scripts/control/system/sysappend.m
@@ -55,10 +55,10 @@
 ##             [D21   | D22 ]
 ## @end group
 ## @end example
-## where @var{D12}, @var{D21}, and @var{D22} are the appropriate dimensioned
+## where @math{D12}, @math{D21}, and @math{D22} are the appropriate dimensioned
 ## blocks of the input parameter @var{d}.
 ## @itemize @bullet
-## @item The leading block @var{D11} of @var{d} is ignored.
+## @item The leading block @math{D11} of @var{d} is ignored.
 ## @item If @var{inname} and @var{outname} are not given as arguments,
 ##      the new inputs and outputs are be assigned default names.
 ## @item @var{yd} is a binary vector of length rows(c) that indicates
--- a/scripts/control/system/syscont.m
+++ b/scripts/control/system/syscont.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{csys}, @var{Acd}, @var{Ccd}] =} syscont (@var{sys})
+## @deftypefn {Function File} {[@var{csys}, @var{acd}, @var{ccd}] =} syscont (@var{sys})
 ## Extract the purely continuous subsystem of an input system.
 ##
 ## @strong{Inputs}
@@ -27,8 +27,8 @@
 ## @table @var
 ## @item csys
 ## is the purely continuous input/output connections of @var{sys}
-## @item Acd
-## @itemx Ccd
+## @item acd
+## @itemx ccd
 ## connections from discrete states to continuous states,
 ## discrete states to continuous outputs, respectively.
 ##
--- a/scripts/control/system/sysdisc.m
+++ b/scripts/control/system/sysdisc.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{dsys}, @var{Adc}, @var{Cdc}] =} sysdisc (@var{sys})
+## @deftypefn {Function File} {[@var{dsys}, @var{adc}, @var{cdc}] =} sysdisc (@var{sys})
 ##
 ## @strong{Inputs}
 ## @var{sys} = system data structure
@@ -27,8 +27,8 @@
 ## @item dsys
 ## purely discrete portion of sys (returned empty if there is
 ## no purely discrete path from inputs to outputs)
-## @item    Adc
-## @itemx   Cdc
+## @item    adc
+## @itemx   cdc
 ## connections from continuous states to discrete states and discrete
 ## outputs, respectively.
 ## @end table
--- a/scripts/control/system/sysdup.m
+++ b/scripts/control/system/sysdup.m
@@ -17,12 +17,12 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} sysdup (@var{Asys}, @var{out_idx}, @var{in_idx})
+## @deftypefn {Function File} {} sysdup (@var{asys}, @var{out_idx}, @var{in_idx})
 ## Duplicate specified input/output connections of a system
 ##
 ## @strong{Inputs}
 ## @table @var
-## @item Asys
+## @item asys
 ## system data structure
 ## @item out_idx
 ## @itemx in_idx
@@ -44,7 +44,7 @@
 ## @group
 ##           ____________________
 ## u1  ----->|                  |----> y1
-##           |       Asys       |
+##           |       asys       |
 ## u2 ------>|                  |----->y2
 ## (in_idx)  -------------------| (out_idx)
 ## @end group
--- a/scripts/control/system/sysgroup.m
+++ b/scripts/control/system/sysgroup.m
@@ -17,22 +17,22 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} sysgroup (@var{Asys}, @var{Bsys})
+## @deftypefn {Function File} {} sysgroup (@var{asys}, @var{bsys})
 ## Combines two systems into a single system
 ##
 ## @strong{Inputs}
-## @var{Asys}, @var{Bsys}: system data structures
+## @var{asys}, @var{bsys}: system data structures
 ##
 ## @strong{Outputs}
-## @math{sys = @r{block diag}(Asys,Bsys)}
+## @math{sys = @r{block diag}(asys,bsys)}
 ## @example
 ## @group
 ##          __________________
 ##          |    ________    |
-## u1 ----->|--> | Asys |--->|----> y1
+## u1 ----->|--> | asys |--->|----> y1
 ##          |    --------    |
 ##          |    ________    |
-## u2 ----->|--> | Bsys |--->|----> y2
+## u2 ----->|--> | bsys |--->|----> y2
 ##          |    --------    |
 ##          ------------------
 ##               Ksys
--- a/scripts/control/system/sysmult.m
+++ b/scripts/control/system/sysmult.m
@@ -17,19 +17,19 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} sysmult (@var{Asys}, @var{Bsys})
+## @deftypefn {Function File} {} sysmult (@var{asys}, @var{bsys})
 ## Compute @math{sys = Asys*Bsys} (series connection):
 ## @example
 ## @group
 ## u   ----------     ----------
-## --->|  Bsys  |---->|  Asys  |--->
+## --->|  bsys  |---->|  asys  |--->
 ##     ----------     ----------
 ## @end group
 ## @end example
 ## A warning occurs if there is direct feed-through
-## from an input of Bsys or a continuous state of Bsys through a discrete
-## output of Bsys to a continuous state or output in Asys (system data
-## structure does not recognize discrete inputs).
+## from an input of Bsys or a continuous state of @var{bsys} through a
+## discrete output of Bsys to a continuous state or output in @var{asys}
+## (system data structure does not recognize discrete inputs).
 ## @end deftypefn
 
 ## Author: John Ingram <ingraje@eng.auburn.edu>
--- a/scripts/control/system/sysprune.m
+++ b/scripts/control/system/sysprune.m
@@ -17,12 +17,12 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} sysprune (@var{Asys}, @var{out_idx}, @var{in_idx})
+## @deftypefn {Function File} {} sysprune (@var{asys}, @var{out_idx}, @var{in_idx})
 ## Extract specified inputs/outputs from a system
 ##
 ## @strong{Inputs}
 ## @table @var
-## @item   Asys
+## @item asys
 ## system data structure
 ## @item out_idx
 ## @itemx in_idx
--- a/scripts/control/system/syssub.m
+++ b/scripts/control/system/syssub.m
@@ -17,22 +17,22 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} syssub (@var{Gsys}, @var{Hsys})
-## returns @math{sys = Gsys - Hsys}
+## @deftypefn {Function File} {} syssub (@var{gsys}, @var{hsys})
+## Return @math{sys = Gsys - Hsys}.
 ##
-## Method: @var{Gsys} and @var{Hsys} are connected in parallel
+## Method: @var{gsys} and @var{hsys} are connected in parallel
 ## The input vector is connected to both systems; the outputs are
-## subtracted.  Returned system names are those of @var{Gsys}.
+## subtracted.  Returned system names are those of @var{gsys}.
 ## @example
 ## @group
 ##          +--------+
-##     +--->|  Gsys  |---+
+##     +--->|  gsys  |---+
 ##     |    +--------+   |
 ##     |                +|
 ## u --+                (_)--> y
 ##     |                -|
 ##     |    +--------+   |
-##     +--->|  Hsys  |---+
+##     +--->|  hsys  |---+
 ##          +--------+
 ## @end group
 ## @end example
--- a/scripts/control/system/zp2ss.m
+++ b/scripts/control/system/zp2ss.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{A}, @var{B}, @var{C}, @var{D}] =} zp2ss (@var{zer}, @var{pol}, @var{k})
+## @deftypefn {Function File} {[@var{a}, @var{b}, @var{c}, @var{d}] =} zp2ss (@var{zer}, @var{pol}, @var{k})
 ## Conversion from zero / pole to state space.
 ## @strong{Inputs}
 ## @table @var
@@ -30,7 +30,7 @@
 ## real scalar (leading coefficient)
 ## @end table
 ## @strong{Outputs}
-##  @var{A}, @var{B}, @var{C}, @var{D}
+##  @var{a}, @var{b}, @var{c}, @var{d}
 ## The state space system
 ## @example
 ## .
--- a/scripts/control/util/__zgpbal__.m
+++ b/scripts/control/util/__zgpbal__.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} __zgpbal__ (@var{Asys})
+## @deftypefn {Function File} {} __zgpbal__ (@var{sys})
 ##
 ## used internally in @code{tzero}; minimal argument checking performed
 ##
--- a/scripts/control/util/zgfmul.m
+++ b/scripts/control/util/zgfmul.m
@@ -18,8 +18,7 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} zgfmul (@var{a}, @var{b}, @var{c}, @var{d}, @var{x})
-##
-## Compute product of zgep incidence matrix @var{F} with vector @var{x}.
+## Compute product of zgep incidence matrix @math{F} with vector @var{x}.
 ## Used by zgepbal (in zgscal) as part of generalized conjugate gradient
 ## iteration.
 ## @end deftypefn
--- a/scripts/control/util/zgreduce.m
+++ b/scripts/control/util/zgreduce.m
@@ -17,7 +17,7 @@
 ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {retsys =} zgreduce (@var{Asys}, @var{meps})
+## @deftypefn {Function File} {} zgreduce (@var{sys}, @var{meps})
 ## Implementation of procedure REDUCE in (Emami-Naeini and Van Dooren,
 ## Automatica, # 1982).
 ## @end deftypefn