Merge pull request #5433 from tacaswell/enh_dashoffset

ENH: pass dash_offset through to gc for Line2D

lib/matplotlib/backends/backend_ps.py

@@ -276,14 +276,16 @@ def set_linecap(self, linecap, store=1):
     def set_linedash(self, offset, seq, store=1):
         if self.linedash is not None:
             oldo, oldseq = self.linedash
-            if seq_allequal(seq, oldseq): return
+            if seq_allequal(seq, oldseq) and oldo == offset:
+                return
 
         if seq is not None and len(seq):
             s="[%s] %d setdash\n"%(_nums_to_str(*seq), offset)
             self._pswriter.write(s)
         else:
             self._pswriter.write("[] 0 setdash\n")
-        if store: self.linedash = (offset,seq)
+        if store:
+            self.linedash = (offset, seq)
 
     def set_font(self, fontname, fontsize, store=1):
         if rcParams['ps.useafm']: return

lib/matplotlib/lines.py

@@ -346,6 +346,7 @@ def __init__(self, xdata, ydata,
         self.set_markersize(markersize)
 
         self._dashSeq = None
+        self._dashOffset = 0
 
         self._markeredgecolor = None
         self._markeredgewidth = None
@@ -1028,6 +1029,7 @@ def set_linestyle(self, ls):
                 raise ValueError()
 
             self.set_dashes(ls[1])
+            self._dashOffset = ls[0]
             self._linestyle = "--"
             return
 
@@ -1198,7 +1200,7 @@ def _draw_solid(self, renderer, gc, path, trans):
     def _draw_dashed(self, renderer, gc, path, trans):
         gc.set_linestyle('dashed')
         if self._dashSeq is not None:
-            gc.set_dashes(0, self._dashSeq)
+            gc.set_dashes(self._dashOffset, self._dashSeq)
 
         renderer.draw_path(gc, path, trans)
 
@@ -1222,6 +1224,7 @@ def update_from(self, other):
         self._markeredgecolor = other._markeredgecolor
         self._markeredgewidth = other._markeredgewidth
         self._dashSeq = other._dashSeq
+        self._dashOffset = other._dashOffset
         self._dashcapstyle = other._dashcapstyle
         self._dashjoinstyle = other._dashjoinstyle
         self._solidcapstyle = other._solidcapstyle