New Visual: Bar

examples/scene/bar_plot.py

@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+# vispy: gallery 2
+# -----------------------------------------------------------------------------
+# Copyright (c) Vispy Development Team. All Rights Reserved.
+# Distributed under the (new) BSD License. See LICENSE.txt for more info.
+# -----------------------------------------------------------------------------
+"""
+Vertical bar plot with Axis 
+===========================
+"""
+
+import numpy as np
+from vispy import scene, app
+
+if __name__ == "__main__":
+
+ canvas = scene.SceneCanvas(keys='interactive', vsync=False)
+ canvas.size = 800, 600
+ canvas.show()
+
+ grid = canvas.central_widget.add_grid()
+ grid.padding = 10
+
+ vb1 = grid.add_view(row=0, col=1, camera='panzoom')
+
+ x_axis1 = scene.AxisWidget(orientation='bottom')
+ x_axis1.stretch = (1, 0.1)
+ grid.add_widget(x_axis1, row=1, col=1)
+ x_axis1.link_view(vb1)
+ y_axis1 = scene.AxisWidget(orientation='left')
+ y_axis1.stretch = (0.1, 1)
+ grid.add_widget(y_axis1, row=0, col=0)
+ y_axis1.link_view(vb1)
+
+ grid_lines1 = scene.visuals.GridLines(parent=vb1.scene)
+
+ bar1 = scene.Bar(height=np.arange(0, 250, 0.5), # for a more traditional horizontal plot, either remove the 
+ bottom=np.arange(0, 125, 0.25), width=0.8, shift=0.5, # orientation paramenter outright
+ color=(0.25, 0.8, 0.), orientation='v', parent=vb1.scene) # or set it to 'h'
+
+ vb1.camera.set_range()
+
+ app.run()

vispy/scene/visuals.py

@@ -232,6 +232,7 @@ def generate_docstring(subclass, clsname):
 
 Arrow = create_visual_node(visuals.ArrowVisual)
 Axis = create_visual_node(visuals.AxisVisual)
+Bar = create_visual_node(visuals.BarVisual)
 Box = create_visual_node(visuals.BoxVisual)
 ColorBar = create_visual_node(visuals.ColorBarVisual)
 Compound = create_visual_node(visuals.CompoundVisual)

vispy/visuals/__init__.py

@@ -12,6 +12,7 @@
 """
 
 from .axis import AxisVisual # noqa
+from .bar import BarVisual # noqa
 from .box import BoxVisual # noqa
 from .cube import CubeVisual # noqa
 from .ellipse import EllipseVisual # noqa

vispy/visuals/bar.py

@@ -0,0 +1,86 @@
+# -*- coding: utf-8 -*-
+# -----------------------------------------------------------------------------
+# Copyright (c) Vispy Development Team. All Rights Reserved.
+# Distributed under the (new) BSD License. See LICENSE.txt for more info.
+# -----------------------------------------------------------------------------
+
+import numpy as np
+from .mesh import MeshVisual
+
+
+class BarVisual(MeshVisual):
+ """Visual that calculates and displays a bar graph
+
+ Parameters
+ ----------
+ data : array-like
+ 1st column is the height, optional 2nd column is bottom
+ height : array-like
+ Height of the bars
+ bottom : array-like
+ Bottom of the bars
+ width : int | float
+ Width of all bars
+ shift : int | float
+ Shift of all bars along the x-axis
+ color : instance of Color
+ Color of the bar.
+ orientation : {'h', 'v'}
+ Orientation of the histogram - 'h' is default
+ """
+
+ def __init__(self, height, bottom=None, width=0.8, shift=0.0, color='w', orientation='h'):
+ if bottom is None:
+ bottom = np.zeros(height.shape[0])
+
+ rr, tris = calc_vertices(height, bottom, width, shift, orientation)
+
+ MeshVisual.__init__(self, rr, tris, color=color)
+
+ def update_data(self, height, bottom=None, width=0.8, shift=0.0, color='w'):
+ if bottom is None:
+ bottom = np.zeros(height.shape[0])
+ rr, tris = calc_vertices(height, bottom, width, shift=shift)
+
+ MeshVisual.set_data(self, rr, tris, color=color)
+
+
+def calc_vertices(height, bottom, width, shift, orientation):
+
+ y_position = np.zeros((height.shape[0], 2))
+
+ y_position[:, 0] = height
+ y_position[:, 1] = bottom
+
+ y_position = y_position.flatten().repeat(2)
+
+ stack_n_x2 = np.arange(0, height.shape[0], dtype=int) 
+ stack_n_x2 = np.expand_dims(stack_n_x2, axis=1)
+ stack_n_x2 = np.repeat(stack_n_x2, 1, axis=1)
+ stack_n_x2 = np.repeat(stack_n_x2, 2, axis=0)
+
+ vertices = np.array([
+ [-width/2 + shift, 1, 0],
+ [width/2 + shift, 1, 0],
+ [width/2 + shift, 0, 0],
+ [-width/2 + shift, 0, 0]])
+
+ vertices = np.tile(vertices, (height.shape[0], 1))
+
+ if orientation == 'h':
+ vertices[:, 0] = vertices[:, 0] + stack_n_x2[:, 0].repeat(2)
+ vertices[:, 1] = y_position
+
+ elif orientation == 'v':
+ vertices[:, 1] = vertices[:, 0] + stack_n_x2[:, 0].repeat(2)
+ vertices[:, 0] = y_position
+ else:
+ raise ValueError('orientation can only be v (vertical) or h (horizontal). You specified: ' + str(orientation))
+
+ base_faces = np.array([[0, 1, 2], [0, 2, 3]])
+
+ base_faces = np.tile(base_faces, (height.shape[0], 1))
+
+ faces = stack_n_x2*4 + base_faces
+
+ return vertices, faces