--- a/scripts/control/base/__bodquist__.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/base/__bodquist__.m	Wed Jan 19 17:16:45 2000 +0000
@@ -27,9 +27,8 @@
 ## @item w
 ## range of frequencies; empty if user wants default
 ## @item out_idx
-## vector output indices or list of output signal names; empty if user wants all
-## @item in_idx
-## vector of input indices of list of input signal names; empty if user wants all
+## @itemx in_idx
+## names or indices of output/input signal names; empty if user wants all
 ## @item rname
 ## name of routine that called __bodquist__ ("bode", "nyquist", or "nichols")
 ## @end table

--- a/scripts/control/base/bode.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/base/bode.m	Wed Jan 19 17:16:45 2000 +0000
@@ -65,6 +65,7 @@
 ## The names or indices of outputs and inputs to be used in the frequency
 ## response.  See @code{sysprune}.
 ##
+## @strong{Example}
 ## @example
 ## bode(sys,[],"y_3",list("u_1","u_4");
 ## @end example
@@ -132,6 +133,8 @@
   endif
 
   [f, w, sys] = __bodquist__ (sys, w, outputs, inputs, "bode");
+  bode_nin = sysdimensions(sys,"in");
+  bode_nout = sysdimensions(sys,"out");
 
   [stname,inname,outname] = sysgetsignals(sys);
   systsam = sysgettsam(sys);

--- a/scripts/control/base/lqg.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/base/lqg.m	Wed Jan 19 17:16:45 2000 +0000
@@ -40,7 +40,7 @@
 ## @itemx  R
 ## state, control weighting respectively.  Control ARE is
 ## @item  in_idx
-## indices of controlled inputs
+## names or indices of controlled inputs (see @code{sysidx}, @code{listidx})
 ##
 ## default: last dim(R) inputs are assumed to be controlled inputs, all
 ## others are assumed to be noise inputs.
@@ -94,7 +94,14 @@
   elseif(nout != columns(Sigv))
     error(["lqg: sys has ",num2str(nout)," outputs, dim(Sigv)=", ...
           num2str(columns(Sigv)),")"])
-  elseif(length(input_list) != columns(R))
+  endif
+
+  ## check for names of signals
+  if(is_signal_list(input_list) | isstr(input_list))
+    input_list = sysidx(sys,"in",input_list);
+  endif
+
+  if(length(input_list) != columns(R))
     error(["lqg: length(input_list)=",num2str(length(input_list)), ...
           ", columns(R)=", num2str(columns(R))]);
   endif

--- a/scripts/control/base/nyquist.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/base/nyquist.m	Wed Jan 19 17:16:45 2000 +0000
@@ -53,8 +53,8 @@
 ## not change excessively from point to point and that singular
 ## points (e.g., crossovers from +/- 180) are accurately shown.
 ## @end enumerate
-## outputs, inputs: the indices of the output(s) and input(s) to be used in
-## the frequency response; see sysprune.
+## outputs, inputs: names or indices of the output(s) and input(s) to be 
+## used in the frequency response; see sysprune.
 ##
 ## @strong{Inputs} (pass as empty to get default values)
 ## @table @var

--- a/scripts/control/system/dmr2d.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/system/dmr2d.m	Wed Jan 19 17:16:45 2000 +0000
@@ -28,12 +28,11 @@
 ## discrete time system;
 ## @code{dmr2d} exits with an error if @var{sys} is not discrete
 ## @item   idx
-## list of states with sampling time @code{sysgettsam(@var{sys})} (may
-## be empty)
+## indices or names of states with sampling time 
+## @code{sysgettsam(@var{sys})} (may be empty); see @code{listidx}
 ## @item   sprefix
 ## list of string prefixes of states with sampling time
-## @code{sysgettsam(@var{sys})}
-## (may be empty)
+## @code{sysgettsam(@var{sys})} (may be empty)
 ## @item   Ts2
 ## sampling time of states not specified by @var{idx}, @var{sprefix}
 ## must be an integer multiple of @code{sysgettsam(@var{sys})}
@@ -84,6 +83,11 @@
 
   elseif(!is_digital(sys))
     error("sys must be discrete-time; continuous time passed");
+  
+  endif
+
+  if(is_signal_list(idx) | isstr(idx))
+    idx = sysidx(sys,"st",idx);
 
   elseif (!(is_vector(idx) | isempty(idx)))
     error(["idx(",num2str(rows(idx)),"x",num2str(columns(idx)), ...
@@ -117,7 +121,7 @@
 
   ## compute number of steps
   if(Ts1 > Ts2)
-    error(["Current sampling time=",num2str(Ts1),"< Ts2=",num2str(Ts2)]);
+    error(["Current sampling time=",num2str(Ts1)," > Ts2=",num2str(Ts2)]);
   endif
   nstp = floor(Ts2/Ts1+0.5);
   if(abs((Ts2 - Ts1*nstp)/Ts1) > 1e-12)
@@ -172,7 +176,7 @@
   ## permute A, B (stname permuted for debugging only)
   da = da(pv,pv);
   db = db(pv,:);
-  stname = stname(pv,:);
+  stname = stname(pv);
 
   ## partition A, B:
   lfidx = length(fidx);
@@ -251,7 +255,7 @@
 
   da = da(pvi,pvi);
   db = db(pvi,:);
-  stname = stname(pvi,:);
+  stname = stname(pvi);
 
   ## construct new system and return
   dsys = ss2sys(da,db,dc,dd,Ts2,0,nz,stname,inname,outname,find(yd == 1));

--- a/scripts/control/system/sysconnect.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/system/sysconnect.m	Wed Jan 19 17:16:45 2000 +0000
@@ -26,8 +26,9 @@
 ## system data structure
 ## @item   out_idx
 ## @itemx  in_idx
-## list of connections indices; @math{y(out_idx(ii))}
-## is connected to @math{u(in_idx(ii))}.
+## names or indices of signals to connect (see @code{sysidx}).
+## The output specified by @math{out_idx(ii)} is connected to the input
+## specified by @math{in_idx(ii)}.
 ## @item   order
 ## logical flag (default = 0)
 ## @table @code
@@ -89,6 +90,14 @@
         ", eps=",num2str(eps)])
   endif
 
+  ## convert signal names to indices
+  if(is_signal_list(input_list) | isstr(input_list))
+    input_list = sysidx(sys,"in",input_list);
+  endif
+  if(is_signal_list(output_list) | isstr(output_list))
+    output_list = sysidx(sys,"out",output_list);
+  endif
+
   ## verify sizes,format of input, output lists
   if( min(size(output_list))*min(size(input_list)) != 1)
     error("output_list and input_list must be vectors");

--- a/scripts/control/system/sysdup.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/system/sysdup.m	Wed Jan 19 17:16:45 2000 +0000
@@ -26,7 +26,7 @@
 ## system data structure
 ## @item out_idx
 ## @itemx in_idx
-## list of connections indices;
+## indices or names of desired signals (see @code{sigidx}).
 ## duplicates are made of @code{y(out_idx(ii))} and @code{u(in_idx(ii))}.
 ## @end table
 ##
@@ -69,6 +69,14 @@
   [nn,nz,mm,pp] = sysdimensions(Asys);
   [aa,bb,cc,dd] = sys2ss(Asys);
 
+  ## check for signal names
+  if(is_signal_list(input_list) | isstr(input_list))
+    input_list = sysidx(Asys,"in",input_list);
+  endif
+  if(is_signal_list(output_list) | isstr(output_list))
+    output_list = sysidx(Asys,"out",output_list);
+  endif
+
   ## first duplicate inputs
   if(is_vector(input_list))
     for ii=1:length(input_list);

--- a/scripts/control/system/sysgetsignals.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/system/sysgetsignals.m	Wed Jan 19 17:16:45 2000 +0000
@@ -41,16 +41,17 @@
 ## @end table
 ##
 ## @item signum
-## Index of signal (or indices of signals if signum is a vector)
+## index(indices) or name(s) or signals; see @code{sysidx}
 ##
 ## @item strflg
 ## flag to return a string instead of a list;  Values:
 ## @table @code
 ## @item 0
-## (default) return a list (even if signum is a scalar)
+## (default) return a list (even if signum specifies an individual signal)
 ##
 ## @item 1
-## return a string.  Exits with an error if signum is not a scalar.
+## return a string.  Exits with an error if signum does not specify an 
+## individual signal.
 ## @end table
 ##
 ## @end table
@@ -166,7 +167,10 @@
         sigid));
     endif
     if(nargin >= 3)
-      if(signum > length(stname))
+      if( is_signal_list(signum) | isstr(signum) )
+        signum = listidx(stname,signum);
+      end
+      if(max(signum) > length(stname))
         error(sprintf("sysgetsignals(sys,\"%s\",%d):only %d entries.\n", ...
           sigid,signum, rows(stname)));
       else

--- a/scripts/control/system/syssetsignals.m	Wed Jan 19 15:21:52 2000 +0000
+++ b/scripts/control/system/syssetsignals.m	Wed Jan 19 17:16:45 2000 +0000
@@ -47,9 +47,9 @@
 ## To desired output continuous/discrete flag.
 ## Set name to 0 for continuous, or 1 for discrete.
 ## @end table
-## @item list
-## vector of indices of outputs, yd, inputs, or
-## states whose respective names should be changed.
+## @item sig_idx
+## indices or names of outputs, yd, inputs, or
+## states whose respective names/values should be changed.
 ##
 ## Default: replace entire list of names/entire yd vector.
 ## @end table
@@ -101,6 +101,16 @@
     strcmp(opt,"in") + strcmp(opt,"st") ) )
     error("opt must be one of [], ""out"", ""yd"", ""in"", or ""st""");
   elseif(nargin == 4)
+    if(is_signal_list(sig_idx) | isstr(sig_idx))
+      ## convert to vector of indices
+      if(opt == "yd")
+        sig_idx = sysidx(sys,"out",sig_idx);
+      else
+        sig_idx = sysidx(sys,opt,sig_idx);
+      endif
+    endif
+
+    ## check index vector
     if(min(size(sig_idx)) > 1)
       disp("syssetsignals: sig_idx=")
       disp(sig_idx);