comparison toolboxes/FullBNT-1.0.7/bnt/examples/static/dtree/transform_data_into_bnt_format.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [bnt_data, old_values] = transform_data_into_bnt_format(data,cnodes)
+% TRANSFORM_DATA_TO_BNT_FORMAT Ensures discrete variables have values 1,2,..,k
+% e.g., if the values of a discrete are [0 1 6], they must be mapped to [1 2 3]
+%
+% data(i,j) is the value for i-th node in j-th case.
+% bnt_data(i,j) is the new value.
+% old_values{i} are the original values for node i.
+% cnodes is the list of all continous nodes, e.g. [3 5] means the 3rd and 5th node is continuous
+%
+% Author: [e-mail]
+% Last updated: Jan. 22, 2002 by Kevin Murphy.
+
+num_nodes=size(data,1);
+num_cases=size(data,2);
+old_values=cell(1,num_nodes);
+
+for i=1:num_nodes
+  if (myismember(i,cnodes)==1)  %cts nodes no need to be transformed 
+    %just copy the data
+    bnt_data(i,:)=data(i,:);
+    continue;
+  end
+  values = data(i,:);
+  sort_v = sort(values); 
+  %remove the duplicate values in sort_v
+  v_set = unique(sort_v);  
+  
+  %transform the values
+  for j=1:size(values,2)
+    index = binary_search(v_set,values(j));
+    if (index==-1)
+      fprintf('value not found in tranforming data to bnt format.\n');   
+      return;
+    end
+    bnt_data(i,j)=index;
+  end
+  old_values{i}=v_set;
+end
+
+
+%%%%%%%%%%%%
+
+function index=binary_search(vector, value)
+% BI_SEARCH do binary search for value in the vector
+% Author: [e-mail]
+% Last updated: Jan. 19, 2002
+
+begin_index=1;
+end_index=size(vector,2); 
+index=-1;
+while (begin_index<=end_index)
+  mid=floor((begin_index+end_index)/2);
+  if (isstr(vector(mid)))
+    % need to write a strcmp to return three result (< = >)
+  else
+    if (value==vector(mid))
+      index=mid;
+      return;
+    elseif (value>vector(mid))
+      begin_index=mid+1;    
+    else
+      end_index=mid-1;
+    end
+  end
+end
+return;