added some support for taking log of line plots with neg data

svn path=/trunk/matplotlib/; revision=925

Author: jdh2358

CHANGELOG

@@ -1,6 +1,8 @@
 New entries should be added at the top
 
- 
+2005-02-05 Added some support for handling log switching for lines
+           that have nonpos data - JDH
+
 2005-02-04 Added Nadia's contour patch - contour now has matlab
            compatible syntax; this also fixed an unequal sized contour
            array bug- JDH

boilerplate.py

@@ -1,5 +1,9 @@
 # wrap the plot commands defined in axes.  The code generated by this
-# file is pasted into pylab.py
+# file is pasted into pylab.py.  We did try to do this the smart way,
+# with callable functions and new.function, but could never get the
+# docstrings right for python2.2.  See
+# http://groups-beta.google.com/group/comp.lang.python/messages/1b14640f3a4ad3dc,b3d7453af21e5f82,17739e70ac6f710c,9d5291fce29cbbb1,c5b578e4ffc6af28,056ff270daa2f414?thread_id=dcd63ec13096a0f6&mode=thread
+
 
 
 _fmtplot = """\

examples/date_demo2.py

@@ -16,7 +16,7 @@
 
 mondays   = WeekdayLocator(MONDAY)    # every monday
 months    = MonthLocator(range(1,13), bymonthday=1)           # every month
-monthsFmt = DateFormatter('%b %d')
+monthsFmt = DateFormatter("%b '%y")
 
 
 quotes = quotes_historical_yahoo('INTC', date1, date2)
@@ -26,7 +26,7 @@
 
 dates = [q[0] for q in quotes]
 opens = [q[1] for q in quotes]
-
+    
 ax = subplot(111)
 plot_date(dates, opens, '-')
 ax.xaxis.set_major_locator(months)

lib/matplotlib/axes.py

@@ -3045,6 +3045,24 @@ def set_xscale(self, value, basex = 10, subsx=None):
         if subsx is None: subsx = range(2, basex)
         assert(value.lower() in ('log', 'linear', ))
         if value == 'log':
+            minx, maxx = self.get_xlim()
+            if minx<=0 or maxx<=0:
+                # find the min pos value in the data
+                xs = []
+                for line in self.lines:
+                    xs.extend(line.get_xdata())
+                for patch in self.patches:
+                    xs.extend([x for x,y in patch.get_verts()])
+                for collection in self.collections:
+                    xs.extend([x for x,y in collection.get_verts()])                    
+                posx = [x for x in xs if x>0]
+                minx = min(posx)
+                maxx = max(posx)
+                # warning, probably breaks inverted axis
+                self.set_xlim((0.1*minx, maxx))
+                
+                            
+                
             self.xaxis.set_major_locator(LogLocator(basex))
             self.xaxis.set_major_formatter(LogFormatterMathtext(basex))
             self.xaxis.set_minor_locator(LogLocator(basex,subsx))
@@ -3125,6 +3143,22 @@ def set_yscale(self, value, basey=10, subsy=None):
         assert(value.lower() in ('log', 'linear', ))
 
         if value == 'log':
+            miny, maxy = self.get_ylim()
+            if miny<=0 or maxy<=0:
+                # find the min pos value in the data
+                ys = []
+                for line in self.lines:
+                    ys.extend(line.get_ydata())
+                for patch in self.patches:
+                    ys.extend([y for x,y in patch.get_verts()])
+                for collection in self.collections:
+                    ys.extend([y for x,y in collection.get_verts()])                    
+                posy = [y for y in ys if y>0]
+                miny = min(posy)
+                maxy = max(posy)
+                # warning, probably breaks inverted axis
+                self.set_ylim((0.1*miny, maxy))
+
             self.yaxis.set_major_locator(LogLocator(basey))
             self.yaxis.set_major_formatter(LogFormatterMathtext(basey))
             self.yaxis.set_minor_locator(LogLocator(basey,subsy))

lib/matplotlib/collections.py

@@ -35,6 +35,11 @@ class Collection(Artist):
     def __init__(self):
         Artist.__init__(self)
 
+
+    def get_verts(self):
+        'return seq of (x,y) in collection'
+        raise NotImplementedError('Derived must override')
+    
     def _get_color(self, c, N=1):
         if looks_like_color(c):
 	    return  [colorConverter.to_rgba(c)]*N
@@ -98,6 +103,7 @@ def __init__(self,
         self._offsets = offsets
 	self._transOffset = transOffset
 
+
     def set_linewidth(self, lw):
         """
 Set the linewidth(s) for the collection.  lw can be a scalar or a
@@ -186,6 +192,23 @@ def draw(self, renderer):
         self._transform.thaw()
 	self._transOffset.thaw()
 	renderer.close_group('polycollection')
+
+
+
+    def get_verts(self):
+        'return seq of (x,y) in collection'
+        if self._offsets is None:
+            offsets = [(0,0)]
+        else:
+            offsets = self._offsets
+        N = max(len(offsets), len(self._verts))
+        vertsall = []
+        for i in range(N):
+            ox, oy = offsets[i%N]
+            verts = self._verts[i%N]
+            vertsall.extend([(x+ox, y+oy) for x,y in verts])
+        return vertsall
+
 
 class RegularPolyCollection(PatchCollection):
     def __init__(self,
@@ -213,7 +236,7 @@ def __init__(self,
 
         theta = (2*math.pi/numsides)*arange(numsides) + rotation
 
-        self._verts = zip( r*sin(theta), r*cos(theta) )
+        self._verts = zip( r*cos(theta), r*sin(theta) )
 
 
 
@@ -239,6 +262,17 @@ def draw(self, renderer):
 	self._transOffset.thaw()
 	renderer.close_group('regpolycollection')
 
+
+
+    def get_verts(self):
+        'return seq of (x,y) in collection'
+        if self._offsets is None:
+            offsets = [(0,0)]
+        else:
+            offsets = self._offsets
+        return [ (x+ox, y+oy) for x,y in self._verts for ox,oy in offsets]
+            
+
 class LineCollection(Collection):
     """
     All parameters must be sequences.  The property of the ith line
@@ -364,3 +398,18 @@ def get_linewidths(self):
 
     def get_colors(self):
         return self._colors
+
+
+    def get_verts(self):
+        'return seq of (x,y) in collection'
+        if self._offsets is None:
+            offsets = [(0,0)]
+        else:
+            offsets = self._offsets
+        N = max(len(offsets), len(self._verts))
+        vertsall = []
+        for i in range(N):
+            ox, oy = offsets[i%N]
+            verts = self._segments[i%N]
+            vertsall.extend([(x+ox, y+oy) for x,y in verts])
+        return vertsall

lib/matplotlib/lines.py

@@ -9,14 +9,15 @@
 import sys
 
 from numerix import Float, alltrue, arange, array, logical_and,\
-     nonzero, searchsorted, take, asarray, ones, where, less, ravel
+     nonzero, searchsorted, take, asarray, ones, where, less, ravel, \
+     greater, logical_and
 from matplotlib import verbose
 from artist import Artist
 from cbook import iterable, is_string_like
 from collections import RegularPolyCollection, PolyCollection
 from colors import colorConverter
 from patches import bbox_artist
-from transforms import lbwh_to_bbox
+from transforms import lbwh_to_bbox, LOG10
 from matplotlib import rcParams
 
 TICKLEFT, TICKRIGHT, TICKUP, TICKDOWN = range(4)
@@ -140,6 +141,7 @@ def __init__(self, xdata, ydata,
         self._lineFunc = self._lineStyles.get(linestyle, self._draw_nothing)
         self._markerFunc = self._markers.get(marker, self._draw_nothing)
 
+        self._logcache = None
 
     def get_window_extent(self, renderer):
         x, y = self._get_numeric_clipped_data_in_range()
@@ -193,6 +195,8 @@ def set_data(self, *args):
             raise RuntimeError('xdata and ydata must be the same length')
 
         if self._useDataClipping: self._xsorted = self._is_sorted(self._x)
+
+        self._logcache = None
 
     def set_data_clipping(self, b):
         """
@@ -210,12 +214,37 @@ def _is_sorted(self, x):
 
     def _get_numeric_clipped_data_in_range(self):
         # if the x or y clip is set, only plot the points in the
-        # clipping region
+        # clipping region.  If log scale is set, only pos data will be
+        # returned
         try: self._xc, self._yc
         except AttributeError: x, y = self._x, self._y
         else: x, y = self._xc, self._yc
 
-            
+        try: logx = self._transform.get_funcx().get_type()==LOG10
+        except RuntimeError: logx = False  # non-separable
+        
+        try: logy = self._transform.get_funcy().get_type()==LOG10
+        except RuntimeError: logy = False  # non-separable
+        
+        if not logx and not logy: return x, y
+
+        if self._logcache is not None:
+            return self._logcache
+
+        Nx = len(x)
+        Ny = len(y)
+
+        if logx: indx = greater(x, 0)
+        else:    indx = ones(len(x))
+
+        if logy: indy = greater(y, 0)
+        else:    indy = ones(len(y))
+
+        ind = nonzero(logical_and(indx, indy))
+        x = take(x, ind)
+        y = take(y, ind)
+
+        self._logcache = x, y
         return x, y
 
     def draw(self, renderer):
@@ -267,8 +296,11 @@ def get_ydata(self):  return self._y
 
 
     def _set_clip(self):
+
 
         if not self._useDataClipping: return
+        #self._logcache = None
+        
         try: self._xmin, self._xmax
         except AttributeError: indx = arange(len(self._x))
         else:
@@ -402,7 +434,7 @@ def set_xdata(self, x):
         except AttributeError: pass
 
         self.set_data(x, self._y)
-
+        
     def set_ydata(self, y):
         """
 Set the data array for y
@@ -427,6 +459,8 @@ def set_xclip(self, *args):
         self._xmin, self._xmax = xmin, xmax
         self._set_clip()
 
+
+        
     def set_yclip(self, *args):
         """
 Set the y clipping range for data clipping to ymin, ymax