Merge pull request #816 from ioam/datetime64_fixes

Datetime64 fixes

holoviews/core/__init__.py

@@ -17,6 +17,7 @@
 Dimension.type_formatters[float] = "%.5g"
 Dimension.type_formatters[np.float32] = "%.5g"
 Dimension.type_formatters[np.float64] = "%.5g"
+Dimension.type_formatters[np.datetime64] = '%Y-%m-%d %H:%M:%S'
 
 
 def public(obj):

holoviews/core/data/__init__.py

@@ -463,7 +463,7 @@ def get_dimension_type(self, dim):
         dim_obj = self.get_dimension(dim)
         if dim_obj and dim_obj.type is not None:
             return dim_obj.type
-        return self.interface.dimension_type(self, dim)
+        return self.interface.dimension_type(self, dim_obj)
 
 
     def dframe(self, dimensions=None):

holoviews/core/data/grid.py

@@ -84,10 +84,8 @@ def validate(cls, dataset):
 
     @classmethod
     def dimension_type(cls, dataset, dim):
-        if dim in dataset.kdims:
-            arr = dataset.data[dim.name]
-        elif dim in dataset.vdims:
-            arr = dataset.data[dim.name]
+        if dim in dataset.dimensions():
+            arr = cls.values(dataset, dim, False, False)
         else:
             return None
         return arr.dtype.type

holoviews/core/data/xarray.py

@@ -78,7 +78,10 @@ def range(cls, dataset, dimension):
         dim = dataset.get_dimension(dimension).name
         if dim in dataset.data:
             data = dataset.data[dim]
-            return data.min().item(), data.max().item()
+            dmin, dmax = data.min().data, data.max().data
+            dmin = dmin if np.isscalar(dmin) else dmin.item()
+            dmax = dmax if np.isscalar(dmax) else dmax.item()
+            return dmin, dmax
         else:
             return np.NaN, np.NaN
 

holoviews/core/dimension.py

@@ -5,6 +5,7 @@
 """
 from __future__ import unicode_literals
 import re
+import datetime as dt
 from operator import itemgetter
 
 import numpy as np
@@ -13,7 +14,7 @@
 from ..core.util import (basestring, sanitize_identifier,
                          group_sanitizer, label_sanitizer, max_range,
                          find_range, dimension_sanitizer, OrderedDict,
-                         safe_unicode, unicode)
+                         safe_unicode, unicode, dt64_to_dt)
 from .options import Store, StoreOptions
 from .pprint import PrettyPrinter
 
@@ -178,7 +179,11 @@ def pprint_value(self, value):
             if callable(formatter):
                 return formatter(value)
             elif isinstance(formatter, basestring):
-                if re.findall(r"\{(\w+)\}", formatter):
+                if isinstance(value, dt.datetime):
+                    return value.strftime(formatter)
+                elif isinstance(value, np.datetime64):
+                    return dt64_to_dt(value).strftime(formatter)
+                elif re.findall(r"\{(\w+)\}", formatter):
                     return formatter.format(value)
                 else:
                     return formatter % value

holoviews/core/util.py

@@ -3,6 +3,7 @@
 import itertools
 import string, fnmatch
 import unicodedata
+import datetime as dt
 from collections import defaultdict
 
 import numpy as np
@@ -917,3 +918,10 @@ def expand_grid_coords(dataset, dim):
     idx = dataset.get_dimension_index(dim)
     return cartesian_product(arrays)[idx]
 
+
+def dt64_to_dt(dt64):
+    """
+    Safely converts NumPy datetime64 to a datetime object.
+    """
+    ts = (dt64 - np.datetime64('1970-01-01T00:00:00Z')) / np.timedelta64(1, 's')
+    return dt.datetime.utcfromtimestamp(ts)

holoviews/plotting/mpl/chart.py

@@ -1,14 +1,16 @@
 from __future__ import unicode_literals
+
 from itertools import product
 
 import numpy as np
 from matplotlib import cm
 from matplotlib import pyplot as plt
 from matplotlib.collections import LineCollection
+from matplotlib.dates import date2num, DateFormatter
 
 import param
 
-from ...core import OrderedDict
+from ...core import OrderedDict, Dimension
 from ...core.util import (match_spec, unique_iterator, safe_unicode,
                           basestring, max_range, unicode)
 from ...element import Points, Raster, Polygons, HeatMap
@@ -59,8 +61,19 @@ class CurvePlot(ChartPlot):
     def get_data(self, element, ranges, style):
         xs = element.dimension_values(0)
         ys = element.dimension_values(1)
-        return (xs, ys), style, {}
+        dims = element.dimensions()
+        if xs.dtype.kind == 'M':
+            dt_format = Dimension.type_formatters[np.datetime64]
+            dims[0] = dims[0](value_format=DateFormatter(dt_format))
+        return (xs, ys), style, {'dimensions': dims}
 
+    def init_artists(self, ax, plot_args, plot_kwargs):
+        xs, ys = plot_args
+        if xs.dtype.kind == 'M':
+            artist = ax.plot_date(xs, ys, '-', **plot_kwargs)[0]
+        else:
+            artist = ax.plot(xs, ys, **plot_kwargs)[0]
+        return {'artist': artist}
 
     def update_handles(self, key, axis, element, ranges, style):
         artist = self.handles['artist']

holoviews/plotting/mpl/element.py

@@ -1,10 +1,11 @@
 import math
 
+import param
+import numpy as np
+import matplotlib.pyplot as plt
 from matplotlib import ticker
 from matplotlib import colors
-import matplotlib.pyplot as plt
-import numpy as np
-import param
+from matplotlib.dates import date2num
 
 from ...core import util
 from ...core import (OrderedDict, NdOverlay, DynamicMap,
@@ -301,7 +302,9 @@ def _set_axis_limits(self, axis, view, subplots, ranges):
         scalex, scaley = True, True
         extents = self.get_extents(view, ranges)
         if extents and not self.overlaid:
-            coords = [coord if np.isreal(coord) else np.NaN for coord in extents]
+            coords = [coord if np.isreal(coord) or isinstance(coord, np.datetime64) else np.NaN for coord in extents]
+            coords = [date2num(util.dt64_to_dt(c)) if isinstance(c, np.datetime64) else c
+                      for c in coords]
             valid_lim = lambda c: util.isnumeric(c) and not np.isnan(c)
             if self.projection == '3d' or len(extents) == 6:
                 l, b, zmin, r, t, zmax = coords

holoviews/plotting/mpl/plot.py

@@ -262,9 +262,6 @@ class GridPlot(CompositePlot):
     show_legend = param.Boolean(default=False, doc="""
         Legends add to much clutter in a grid and are disabled by default.""")
 
-    tick_format = param.String(default="%.2f", doc="""
-        Formatting string for the GridPlot ticklabels.""")
-
     xaxis = param.ObjectSelector(default='bottom',
                                  objects=['bottom', 'top', None], doc="""
         Whether and where to display the xaxis, supported options are
@@ -496,13 +493,15 @@ def _layout_axis(self, layout, axis):
         yticks = [(plot_height/2)+(r*(plot_height+border_height)) for r in range(self.rows)]
 
         layout_axis.set_xticks(xticks)
-        layout_axis.set_xticklabels(self._process_ticklabels(sorted(set(dim1_keys)), dims[0]))
+        layout_axis.set_xticklabels([dims[0].pprint_value(l)
+                                     for l in sorted(set(dim1_keys))])
         for tick in layout_axis.get_xticklabels():
             tick.set_rotation(self.xrotation)
 
         ydim = dims[1] if layout.ndims > 1 else None
         layout_axis.set_yticks(yticks)
-        layout_axis.set_yticklabels(self._process_ticklabels(sorted(set(dim2_keys)), ydim))
+        layout_axis.set_yticklabels([ydim.pprint_value(l) if ydim else ''
+                                     for l in sorted(set(dim2_keys))])
         for tick in layout_axis.get_yticklabels():
             tick.set_rotation(self.yrotation)
 
@@ -529,19 +528,6 @@ def _layout_axis(self, layout, axis):
         return layout_axis
 
 
-    def _process_ticklabels(self, labels, dim):
-        formatted_labels = []
-        for k in labels:
-            if dim and dim.value_format:
-                k = dim.value_format(k)
-            elif not isinstance(k, (str, type(None))):
-                k = self.tick_format % k
-            elif k is None:
-                k = ''
-            formatted_labels.append(k)
-        return formatted_labels
-
-
     def _adjust_subplots(self, axis, subaxes):
         bbox = axis.get_position()
         l, b, w, h = bbox.x0, bbox.y0, bbox.width, bbox.height

holoviews/plotting/mpl/raster.py

@@ -379,8 +379,9 @@ def update_frame(self, key, ranges=None):
     def _get_axis_kwargs(self):
         xdim = self.layout.kdims[0]
         ydim = self.layout.kdims[1] if self.layout.ndims > 1 else None
-        xticks = (self._xticks, self._process_ticklabels(self._xkeys, xdim))
-        yticks = (self._yticks, self._process_ticklabels(self._ykeys, ydim))
+        xticks = (self._xticks, [xdim.pprint_value(l) for l in self._xkeys])
+        yticks = (self._yticks, [ydim.pprint_value(l) if ydim else ''
+                                 for l in self._ykeys])
         return dict(xlabel=xdim.pprint_label, ylabel=ydim.pprint_label if ydim else '',
                     xticks=xticks, yticks=yticks)