--- /dev/null
+## Copyright (C) 2005-2012 Ivana Varekova
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} treeplot (@var{tree})
+## @deftypefnx {Function File} {} treeplot (@var{tree}, @var{node_style}, @var{edge_style})
+## Produce a graph of tree or forest. The first argument is vector of
+## predecessors, optional parameters @var{node_style} and @var{edge_style}
+## define the output style. The complexity of the algorithm is O(n) in
+## terms of is time and memory requirements.
+## @seealso{etreeplot, gplot}
+## @end deftypefn
+
+function treeplot (tree, node_style = "ko", edge_style = "r")
+
+ if (nargin < 1 || nargin > 3 || nargout > 0)
+ print_usage ();
+ endif
+
+ if (! ismatrix (tree) || rows (tree) != 1 || ! isnumeric (tree)
+ || ! isvector (tree) || any (tree > length (tree)))
+ error ("treeplot: TREE must be a vector of predecessors");
+ endif
+
+ ## Verify node_style
+ if (nargin > 1)
+ if (isempty (regexp (node_style, '[ox+*]', 'once')))
+ node_style = [node_style, "o"];
+ endif
+ endif
+
+ ## Make it a row vector.
+ tree = tree(:)';
+
+ ## The count of nodes of the graph.
+ num_nodes = length (tree);
+
+ ## The number of children.
+ num_children = zeros (1, num_nodes+1);
+
+ for i = 1:num_nodes
+ ## VEC_OF_CHILD is helping vector which is used to speed up the
+ ## choose of descendant nodes.
+
+ num_children(tree(i)+1) = num_children(tree(i)+1) + 1;
+ endfor
+ pos = 1;
+ start = zeros (1, num_nodes+1);
+ xhelp = zeros (1, num_nodes+1);
+ stop = zeros (1, num_nodes+1);
+ for i = 1:num_nodes+1
+ start(i) = pos;
+ xhelp(i) = pos;
+ pos += num_children(i);
+ stop(i) = pos;
+ endfor
+ for i = 1:num_nodes
+ vec_of_child(xhelp(tree(i)+1)) = i;
+ xhelp(tree(i)+1) = xhelp(tree(i)+1)+1;
+ endfor
+
+ ## The number of "parent" (actual) node (it's descendants will be
+ ## browse in the next iteration).
+ par_number = 0;
+
+ ## The x-coordinate of the left most descendant of "parent node"
+ ## this value is increased in each leaf.
+ left_most = 0;
+
+ ## The level of "parent" node (root level is num_nodes).
+ level = num_nodes;
+
+ ## Num_nodes - max_ht is the height of this graph.
+ max_ht = num_nodes;
+
+ ## 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".
+ stk = [-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 (par_number != -1)
+ if (start(par_number+1) < stop(par_number+1))
+ idx = vec_of_child(start(par_number+1):stop(par_number+1)-1);
+ else
+ idx = zeros (1, 0);
+ endif
+ ## Add to idx the vector of parent descendants.
+ stk = [stk; [idx', ones(fliplr(size(idx)))*par_number]];
+ ## Add to stack the records relevant to parent descandant s.
+ if (par_number != 0)
+ skelet = [skelet; ([ones(size(idx))*par_number; idx])(:)];
+ endif
+
+ ## If there is not any descendant of "parent node":
+ if (stk(end,2) != par_number)
+ left_most++;
+ x_coordinate_r(par_number) = left_most;
+ max_ht = min (max_ht, level);
+ if (length(stk) > 1 && find ((shift(stk,1)-stk) == 0) > 1
+ && stk(end,2) != stk(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(stk(:,2),1)-stk(:,2)) == 0))(end) + 1;
+ par_number_vec = stk(position:end,2);
+ ## The vector of removed nodes (the content of stack form
+ ## position to end).
+ skelet = [skelet; flipud(par_number_vec)];
+ level += length (par_number_vec);
+ ## The level have to be decreased.
+ x_coordinate_r(par_number_vec) = left_most;
+ stk(position:end,:) = [];
+ endif
+ ## Remove the next node from "searched branch".
+ stk(end,:) = [];
+ ## Choose new "parent node".
+ par_number = stk(end,1);
+ ## If there is another branch start to search it.
+ if (par_number != -1)
+ skelet = [skelet; stk(end,2); par_number];
+ y_coordinate(par_number) = level;
+ x_coordinate_l(par_number) = left_most + 1;
+ endif
+ else
+ ## There were descendants of "parent nod" choose the last of
+ ## them and go on through it.
+ level--;
+ par_number = stk(end,1);
+ y_coordinate(par_number) = level;
+ x_coordinate_l(par_number) = left_most + 1;
+ endif
+ endwhile
+
+ ## Calculate the x coordinates (the known values are the position
+ ## of most left and most right descendants).
+ x_coordinate = (x_coordinate_l + x_coordinate_r) / 2;
+
+ ## FIXME -- we should probably stuff all the arguments into a cell
+ ## array and make a single call to plot here so we can avoid
+ ## setting the hold state...
+
+ hold_is_on = ishold ();
+ unwind_protect
+ ## Plot graph nodes.
+ plot (x_coordinate, y_coordinate, node_style);
+
+ ## Helping command - usable for plotting edges
+ skelet = [skelet; 0];
+
+ ## Draw graph edges.
+ idx = find (skelet == 0);
+
+ hold ("on");
+ ## 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
+ plot (x_coordinate(skelet(istart:istop)),
+ y_coordinate(skelet(istart:istop)), edge_style);
+ endfor
+
+ ## Set axis and graph size.
+ axis ([0.5, left_most+0.5, max_ht-0.5, num_nodes-0.5], "nolabel");
+
+ unwind_protect_cleanup
+ if (! hold_is_on)
+ hold ("off");
+ endif
+ end_unwind_protect
+
+endfunction
+
+%!demo
+%! % Plot a simple tree plot
+%! treeplot([2 4 2 0 6 4 6])
+
+%!demo
+%! % Plot a simple tree plot defining the edge and node styles
+%! treeplot([2 4 2 0 6 4 6], "b+", "g")
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff