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# Major library imports
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from numpy import argsort, array, concatenate, inf, invert, isnan, \
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take, transpose, zeros
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take, transpose, zeros, sqrt, argmin, clip, column_stack
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# Enthought library imports
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from enable.api import black_color_trait, ColorTrait, LineStyle
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from traits.api import Enum, Float, List, Str
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from traits.api import Enum, Float, List, Str, Property, Tuple, cached_property
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from traitsui.api import Item, View
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# Local relative imports
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_cached_screen_pts = List
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def hittest(self, screen_pt, threshold=7.0):
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def hittest(self, screen_pt, threshold=7.0, return_distance = False):
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Tests whether the given screen point is within *threshold* pixels of
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any data points on the line. If so, then it returns the (x,y) value of
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a data point near the screen point. If not, then it returns None.
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Note: This only checks data points and *not* the actual line segments
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# First, check screen_pt is directly on a point in the lineplot
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ndx = self.map_index(screen_pt, threshold)
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if ndx is not None:
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return (self.index.get_data()[ndx], self.value.get_data()[ndx])
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# screen_pt is one of the points in the lineplot
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data_pt = (self.index.get_data()[ndx], self.value.get_data()[ndx])
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scrn_pt = self.map_screen(data_pt)
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dist = sqrt((screen_pt[0] - scrn_pt[0])**2
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+ (screen_pt[1] - scrn_pt[1])**2)
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return (data_pt[0], data_pt[1], dist)
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data_x = self.map_data(screen_pt)
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# We now must check the lines themselves
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# Must check all lines within threshold along the major axis,
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# so determine the bounds of the region of interest in dataspace
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if self.orientation == "h":
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dmax = self.map_data((screen_pt[0]+threshold, screen_pt[1]))
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dmin = self.map_data((screen_pt[0]-threshold, screen_pt[1]))
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dmax = self.map_data((screen_pt[0], screen_pt[1]+threshold))
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dmin = self.map_data((screen_pt[0], screen_pt[1]-threshold))
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xmin, xmax = self.index.get_bounds()
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if xmin <= data_x <= xmax:
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if self.orientation == "h":
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# Now compute the bounds of the region of interest as indexes
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ndx1 = len(self.value.get_data())-1
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ndx1 = reverse_map_1d(self.index.get_data(), dmin,
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self.index.sort_order)
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ndx2 = len(self.value.get_data())-1
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ndx2 = reverse_map_1d(self.index.get_data(), dmax,
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self.index.sort_order)
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start_ndx = max(0, min(ndx1-1, ndx2-1,))
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end_ndx = min(len(self.value.get_data())-1, max(ndx1+1, ndx2+1))
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# Compute the distances to all points in the range of interest
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start = array([ self.index.get_data()[start_ndx:end_ndx],
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self.value.get_data()[start_ndx:end_ndx] ])
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end = array([ self.index.get_data()[start_ndx+1:end_ndx+1],
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self.value.get_data()[start_ndx+1:end_ndx+1] ])
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# Convert to screen points
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s_start = transpose(self.map_screen(transpose(start)))
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s_end = transpose(self.map_screen(transpose(end)))
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# t gives the parameter of the closest point to screen_pt
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# on the line going from s_start to s_end
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t = _closest_point(screen_pt, s_start, s_end)
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# Restrict to points on the line segment s_start->s_end
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# Gives the corresponding point on the line
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px, py = _t_to_point(t, s_start, s_end)
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# Calculate distances
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dist = sqrt((px - screen_pt[0])**2 +
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(py - screen_pt[1])**2)
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# And return if it is good
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if dist[n] <= threshold:
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best_pt = self.map_data((px[n], py[n]), all_values=True)
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return [best_pt[0], best_pt[1], dist[n]]
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interp_val = self.interpolate(data_x)
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interp_y = self.value_mapper.map_screen(interp_val)
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if abs(sy - interp_y) <= threshold:
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return reverse_map_1d(self.index.get_data(), data_x,
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self.index.sort_order)
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def interpolate(self, index_value):
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def _get_effective_color(self):
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alpha = self.color_[-1] if len(self.color_) == 4 else 1
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c = self.color_[:3] + (alpha * self.alpha,)
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def _closest_point(target, p1, p2):
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'''Utility function for hittest:
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finds the point on the line between p1 and p2 to
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the target. Returns the 't' value of that point
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where the line is parametrized as
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Notably, if t=0 is p1, t=2 is p2 and anything outside
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that range is a point outisde p1, p2 on the line
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Note: can divide by zero, so user should check for that'''
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t = ((p1[0] - target[0])*(p1[0]-p2[0]) \
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+ (p1[1] - target[1])*(p1[1]-p2[1]))\
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/ ((p1[0] - p2[0])*(p1[0] - p2[0]) + (p1[1] - p2[1])*(p1[1] - p2[1]))
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def _t_to_point(t, p1, p2):
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'''utility function for hittest for use with _closest_point
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returns the point corresponding to the parameter t
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on the line going between p1 and p2'''
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return ( p1[0]*(1-t) + p2[0]*t,
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p1[1]*(1-t) + p2[1]*t )
added
removed
chaco/lineplot.py
