Ensure three minor ticks always drawn (SF# 2924245). Patch by Neil Crighton.

svn path=/trunk/matplotlib/; revision=8082

Author: astraw

CHANGELOG

@@ -1,3 +1,6 @@
+2009-01-16 Ensure three minor ticks always drawn (SF# 2924245). Patch
+           by Neil Crighton. -ADS
+
 2010-01-16 Applied patch by Ian Thomas to fix two contouring
            problems: now contourf handles interior masked regions,
            and the boundaries of line and filled contours coincide. - EF

lib/matplotlib/ticker.py

@@ -1320,15 +1320,13 @@ def __call__(self):
         except IndexError:
             raise ValueError('Need at least two major ticks to find minor '
                              'tick locations')
-        # see whether major step should be divided by 5, 4 or 2. This
+        # see whether major step should be divided by 5, 4. This
         # should cover most cases.
         temp = float(('%e' % majorstep).split('e')[0])
         if temp % 5 < 1e-10:
             minorstep = majorstep / 5.
-        elif temp % 2 < 1e-10:
-            minorstep = majorstep / 4.
         else:
-            minorstep = majorstep / 2.
+            minorstep = majorstep / 4.
 
         tmin = majorlocs[0] - majorstep
         tmax = majorlocs[-1] + majorstep