[Octave-cvsupdate] octave-forge/main/plot get_graph_data.m,1.1,1.2

[andy a. <aa...@us...>]

Update of /cvsroot/octave/octave-forge/main/plot
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv5611/main/plot

Modified Files:
	get_graph_data.m 
Log Message:
complete - appears to work

Index: get_graph_data.m
===================================================================
RCS file: /cvsroot/octave/octave-forge/main/plot/get_graph_data.m,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -d -r1.1 -r1.2
--- get_graph_data.m	6 Dec 2004 16:19:17 -0000	1.1
+++ get_graph_data.m	6 Dec 2004 17:38:24 -0000	1.2
@@ -29,30 +29,61 @@
    usage('get_graph_data( xaxis, yaxis )'); 
 end
 
-printf('click (with mouse #1) x axis points, then (mouse #2)\n');
-fflush(stdout);
-[xa_x,xa_y]= grab();
-if length(xa_x) ~= length(xaxis)
-   error(sprintf('You specified %d xaxis points, but entered %d', ...
-         length(xaxis), length(xa_x) ));
-end
-x_islog= test_log( xa_x, xa_y, xaxis, 'x axis');
+[xa_x, xa_y, xa_n, x_islog]= get_ax_points( xaxis, 'x axis');
+[ya_x, ya_y, ya_n, y_islog]= get_ax_points( yaxis, 'y axis');
 
+% Based on entered points, we want to see if the axis is
+% rotated (like in a scanned image, for example
+X=[xa_x,xa_y,0*xa_y+1;ya_x,ya_y,0*ya_y+1];
+Y=[xa_n,0*xa_n;0*ya_n,ya_n];
+rot_ax= X\Y;
+printf('X axis is at %5.2f degrees\n',  ...
+       180/pi*atan2( rot_ax(1,2), rot_ax(1,1))  );
+printf('Y axis is at %5.2f degrees\n',  ...
+       180/pi*atan2( rot_ax(2,2), rot_ax(2,1)) );
 
-printf('click (with mouse #1) y axis points, then (mouse #2)\n');
+printf('Select points to convert. Press Mouse #2 or #3 to quit\n');
 fflush(stdout);
-[ya_x,ya_y]= grab();
-if length(ya_x) ~= length(yaxis)
-   error(sprintf('You specified %d yaxis points, but entered %d', ...
-         length(yaxis), length(ya_x) ));
-end
-y_islog= test_log( ya_x, ya_y, yaxis, 'y axis');
+[x,y]= grab();
+dconv= [x,y,x*0+1]*rot_ax;
+
+x= dconv(:,1);
+if x_islog; x= 10.^x; end
+y= dconv(:,2);
+if y_islog; y= 10.^y; end
+
+function [a_x, a_y, a_n, islog]= get_ax_points( ax_pts, ax_text);
+    printf(sprintf( ...
+         'click (with mouse #1) %s points, then (mouse #2)\n', ax_text));
+    fflush(stdout);
+    [a_x,a_y]= grab();
+    if length(a_x) ~= length(ax_pts)
+       error(sprintf('You specified %d %s points, but entered %d', ...
+             ax_text, length(ax_pts), length(a_x) ));
+    end
+    islog= test_log( a_x, a_y, ax_pts, ax_text);
+    if islog
+       a_n= log10(ax_pts(:));
+    else 
+       a_n= ax_pts(:);
+    end
+endfunction
  
 
-function ll=test_log( dx, dy, dfit, ax_test )
+% Guess at whether axes are linear or logarithmic
+function ll=test_log( dx, dy, dfit, ax_text )
    if length(dx)<3
-      warn(sprintf('Can t test linear or log fit using %d points', ...
+      printf(sprintf('Warning: Can t test fit using %d points', ...
             length(dx)))
+% try a heuristic test for linear
+      if any(dfit)==0 || (max(dfit)/min(dfit) < 10)
+          printf(sprintf('GUESSING axis %s is LINEAR\n', ax_text));
+          ll=0;
+      else
+          printf(sprintf('GUESSING axis %s is LOGARITHMIC\n', ax_text));
+          ll=1;
+      end
+      return
    end
    dx= dx(:); dy=dy(:); dfit= dfit(:);
 
@@ -69,10 +100,10 @@
    dlogfit= min([dlogfit1, dlogfit2]);
 
    if dlinfit < dlogfit
-      printf(sprintf('axis %s is LINEAR\n', ax_test));
+      printf(sprintf('axis %s is LINEAR\n', ax_text));
       ll=0;
    else
-      printf(sprintf('axis %s is LOGARITHMIC\n', ax_test));
+      printf(sprintf('axis %s is LOGARITHMIC\n', ax_text));
       ll=1;
    end
 endfunction