--- a/scripts/sparse/treeplot.m
+++ b/scripts/sparse/treeplot.m
@@ -28,119 +28,149 @@
 function treeplot (Tree, NodeS, EdgeS)
 
   if (nargin < 1 || nargin > 3 || nargout > 0)
-    error ("treeplot: wrong number of input/output arguments");
+    print_usage ();
   else
-    if (!ismatrix(Tree) || size(Tree)(1) != 1 || !isnumeric(Tree) 
-        || !isvector(Tree) || any(Tree>length (Tree)))
+    if (! ismatrix (Tree) || rows (Tree) != 1 || ! isnumeric (Tree) 
+        || ! isvector (Tree) || any (Tree > length (Tree)))
       error ("treeplot: the first input argument must be a vector of predecessors");
-    else	
-    
-      NodeStyle = "0*;;";                  ## the inicialization of node end edge style
+    else
+      ## the inicialization of node end edge style
+      NodeStyle = "0*;;";
       EdgeStyle = "1;;";      
       if (nargin > 2)
         EdgeStyle = EdgeS;
         if (nargin > 1) 
-	  if ((length(findstr(NodeS,"*")) == 0) 
-	    && (length(findstr(NodeS,"+")) == 0) 
-	    && (length(findstr(NodeS,"x")) == 0) )
-	    NodeStyle = [NodeS,"o"];
+	  if (length (findstr (NodeS, "*")) == 0
+	      && length (findstr (NodeS, "+")) == 0
+	      && length (findstr (NodeS, "x")) == 0)
+	    NodeStyle = [NodeS, "o"];
 	  else
 	    NodeStyle = NodeS;
 	  endif
         endif
       endif
-      
+
       Tree = Tree(:)';		            ## make it a row vector
       NodNumber = length (Tree);            ## the count of nodes of the graph
-      ChildNumber = zeros (1,NodNumber+1);  ## the number of childrens
+      ChildNumber = zeros (1, NodNumber+1); ## the number of childrens
       
-      for i = 1:(NodNumber)       ## VecOfChild is helping vector which is used to speed up the
-                                  ##   choose of descendant nodes
+      for i = 1:NodNumber
+        ## VecOfChild is helping vector which is used to speed up the
+        ## choose of descendant nodes
 
         ChildNumber(Tree(i)+1) = ChildNumber(Tree(i)+1) + 1;
       endfor
       Pos = 1;
-      for i = 1:(NodNumber+1)
+      for i = 1:NodNumber+1
         Start(i) = Pos;
 	Help(i) = Pos;
-	Pos = Pos + ChildNumber(i);
+	Pos += ChildNumber(i);
 	Stop(i) = Pos;
       endfor
       for i = 1:NodNumber        
         VecOfChild(Help(Tree(i)+1)) = i;  
-	Help(Tree(i)+1)=Help(Tree(i)+1)+1;
-      endfor                    ## VecOfChild is helping vector which is used to speed up the
-                                ##   choose of descendant nodes
-				
-      ParNumber = 0;            ## the number of "parent" (actual) node (it's descendants will 
-                                ##   be browse in the next iteration)
-      LeftMost = 0;		## the x-coordinate of the left most descendant of "parent node"
-                                ##   this value is increased in each leaf		
-      Level = NodNumber;        ## the level of "parent" node (root level is NodNumber)
-      Max = NodNumber;          ## NodNumber - Max is the height of this graph
-      St = [-1,0];		## main stack - each item consists of two numbers - the number of node and
-                                ##   the number it's of parent node
-				##   on the top of stack there is "parent node"
-      Skelet = 0;		## stack which is use to draw the graph edge (it 
-                                ##   have to be uninterupted line)
-      while (ParNumber!=-1)     ## the top of the stack
+	Help(Tree(i)+1) = Help(Tree(i)+1)+1;
+      endfor
+
+      ## the number of "parent" (actual) node (it's descendants will be
+      ## browse in the next iteration)
+      ParNumber = 0;
+
+      ## the x-coordinate of the left most descendant of "parent node"
+      ## this value is increased in each leaf		
+      LeftMost = 0;
+
+      ## the level of "parent" node (root level is NodNumber)
+      Level = NodNumber;
+
+      ## NodNumber - Max is the height of this graph
+      Max = NodNumber;
+
+      ## main stack - each item consists of two numbers - the number of
+      ## node and the number it's of parent node on the top of stack
+      ## there is "parent node"
+      St = [-1,0];
+
+      ## stack which is use to draw the graph edge (it have to be
+      ## uninterupted line)
+      Skelet = 0;
+
+      ## the top of the stack
+      while (ParNumber != -1)
 	if (Start(ParNumber+1) < Stop(ParNumber+1))
 	  idx = VecOfChild(Start(ParNumber+1):Stop(ParNumber+1)-1);
 	else
-	  idx = zeros(1,0);
-	endif                   ## add to idx the vector of parent descendants
+	  idx = zeros (1, 0);
+	endif
+        ## add to idx the vector of parent descendants
 	St = [St ; [idx', ones(fliplr(size(idx)))*ParNumber]];
-	                        ## add to stack the records relevant to parent descandant s
+	## add to stack the records relevant to parent descandant s
 	if (ParNumber != 0)
-	  Skelet = [Skelet ; ([ones(size(idx))*ParNumber; idx])(:)];
+	  Skelet = [Skelet; ([ones(size(idx))*ParNumber; idx])(:)];
 	endif
-	if (St(end,2) != ParNumber)  ## if there is not any descendant of "parent node":
+
+	## if there is not any descendant of "parent node":
+	if (St(end,2) != ParNumber)
 	  LeftMost = LeftMost + 1;
           XCoordinateR(ParNumber) = LeftMost;           
 	  Max = min (Max, Level);
-          if ((length(St)>1) && (find((shift(St,1)-St) == 0) >1) && St(end,2) != St(end-1,2))
-	                             ## return to the nearest branching
-            Position = (find((shift(St(:,2),1)-St(:,2)) == 0))(end)+1;      ## the position to return
-                          ## position is the position on the stack, where should be started 
-			  ## further search (there are two nodes which has the same parent node)
+          if ((length(St)>1) && (find((shift(St,1)-St) == 0) >1)
+	      && St(end,2) != St(end-1,2))
+	    ## return to the nearest branching the position to return
+	    ## position is the position on the stack, where should be
+	    ## started further search (there are two nodes which has the
+	    ## same parent node)
+            Position = (find((shift(St(:,2),1)-St(:,2)) == 0))(end)+1;
             ParNumberVec = St(Position:end,2);
-                          ## the vector of removed nodes (the content of stack form position to end)
+            ## the vector of removed nodes (the content of stack form
+	    ## position to end)
             Skelet = [Skelet; flipud(ParNumberVec)];
             Level = Level + length(ParNumberVec);
-	                  ## the level have to be decreased
+	    ## the level have to be decreased
             XCoordinateR(ParNumberVec) = LeftMost;
             St(Position:end,:) = [];
           endif	
-	  St(end,:) = [];       	## remove the next node from "searched branch"
-          ParNumber = St(end,1);	## choose new "parent node"
-	  if (ParNumber != -1)		## if there is another branch start to search it
+       	  ## remove the next node from "searched branch"
+	  St(end,:) = [];
+	  ## choose new "parent node"
+          ParNumber = St(end,1);
+	  ## if there is another branch start to search it
+	  if (ParNumber != -1)
 	    Skelet = [Skelet ; St(end,2); ParNumber];
             YCoordinate(ParNumber) = Level;	
 	    XCoordinateL(ParNumber) = LeftMost + 1;
 	  endif
-	else                      ## there were descendants of "parent nod"
-          Level = Level - 1;      ## choose the last of them and go on through it
+	else
+          ## there were descendants of "parent nod" choose the last of
+	  ## them and go on through it
+          Level--;
 	  ParNumber = St(end,1);
 	  YCoordinate(ParNumber) = Level;     
 	  XCoordinateL(ParNumber) = LeftMost+1;
 	endif
       endwhile
 
-      XCoordinate = (XCoordinateL + XCoordinateR) / 2;     ## calculate the x coordinates 
-               ## (the known values are the position of most left and most right descendants)
+      ## calculate the x coordinates (the known values are the position
+      ## of most left and most right descendants)
+      XCoordinate = (XCoordinateL + XCoordinateR) / 2;
 
-      axis ([0.5 LeftMost+0.5 Max-0.5 NodNumber-0.5], "nolabel");  ## set axis and graph size 
-      
-      plot (XCoordinate,YCoordinate,NodeStyle);           ## plot grah nodes 
       hold ("on");
+
+      ## plot grah nodes 
+      plot (XCoordinate,YCoordinate,NodeStyle);
       
-      Skelet = [Skelet; 0];     ## helping command - usable for plotting edges
+      ## helping command - usable for plotting edges
+      Skelet = [Skelet; 0];
       
-      idx = find (Skelet == 0);                           ## draw graph edges 
+      ## draw graph edges 
+      idx = find (Skelet == 0);
        
-      for i = 2:length(idx)                               ## plot each tree component in one loop
-	istart = idx(i-1) + 1;                            ## tree component start
-	istop = idx(i) - 1;                               ## tree component end
+      ## plot each tree component in one loop
+      for i = 2:length(idx)
+        ## tree component start
+	istart = idx(i-1) + 1;
+        ## tree component end
+	istop = idx(i) - 1;
 	if (istop - istart < 1)                          
 	  continue;
 	endif
@@ -148,6 +178,9 @@
 	      YCoordinate(Skelet(istart:istop)), EdgeStyle)
       endfor
       
+      ## set axis and graph size 
+      axis ([0.5, LeftMost+0.5, Max-0.5, NodNumber-0.5], "nolabel");
+      
       hold ("off");
       
     endif