Fix bug when plotting all missing data

Signed-off-by: Jim Easterbrook <jim@jim-easterbrook.me.uk>

src/pywws/Plot.py

@@ -887,6 +887,7 @@ def PlotData(self, plot_no, plot, source):
             subplot.ycalc = compile(subplot.ycalc, '<string>', 'eval')
             subplot.last_ycalcs = 0.0
             subplot.last_idx = None
+            subplot.using = '($2)'
             subplots.append(subplot)
         for data in source[start:stop]:
             for subplot in subplots:
@@ -915,6 +916,8 @@ def PlotData(self, plot_no, plot, source):
                     values = (idx.isoformat(),) + value
                     vformat = '%s' + (' %g' * len(value)) + '\n'
                     subplot.dat.write(vformat % values)
+                    subplot.using = ':'.join(
+                        '($%d)' % x for x in range(2, len(values)+1))
                     subplot.last_ycalcs = value[0]
                 except TypeError:
                     if not subplot.cummulative:
@@ -959,9 +962,8 @@ def PlotData(self, plot_no, plot, source):
                 style = 'smooth unique lc %s lw %g' % (colour, width)
             axes = subplot.subplot.get_value('axes', 'x1y1')
             title = subplot.subplot.get_value('title', '')
-            using = ':'.join('($%d)' % x for x in range(2, len(values)+1))
             result += u' "%s" using 1:%s axes %s %s title "%s"%s' % (
-                subplot.dat_file, using, axes, style, title, whiskerbars)
+                subplot.dat_file, subplot.using, axes, style, title, whiskerbars)
             if subplot_no != subplot_count - 1:
                 result += u', \\'
             result += u'\n'

src/pywws/__init__.py

@@ -1,3 +1,3 @@
-__version__ = '17.01.0'
-_release = '1372'
-_commit = '7d691f1'
+__version__ = '17.02.0'
+_release = '1373'
+_commit = '73907d3'