Added ErrorBarItem to repository

examples/ErrorBarItem.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+"""
+Demonstrates basic use of ErrorBarItem
+
+"""
+
+import initExample ## Add path to library (just for examples; you do not need this)
+
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtGui
+import numpy as np
+
+import pyqtgraph as pg
+import numpy as np
+
+x = np.arange(10)
+y = np.arange(10) %3
+top = np.linspace(1.0, 3.0, 10)
+bottom = np.linspace(2, 0.5, 10)
+
+plt = pg.plot()
+err = pg.ErrorBarItem(x=x, y=y, top=top, bottom=bottom, beam=0.5)
+plt.addItem(err)
+plt.plot(x, y, symbol='o')
+
+## Start Qt event loop unless running in interactive mode or using pyside.
+if __name__ == '__main__':
+    import sys
+    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+        QtGui.QApplication.instance().exec_()

pyqtgraph/graphicsItems/ErrorBarItem.py

@@ -0,0 +1,133 @@
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtGui, QtCore
+from .GraphicsObject import GraphicsObject
+
+__all__ = ['ErrorBarItem']
+
+class ErrorBarItem(GraphicsObject):
+    def __init__(self, **opts):
+        """
+        Valid keyword options are:
+        x, y, height, width, top, bottom, left, right, beam, pen
+        
+        x and y must be numpy arrays specifying the coordinates of data points.
+        height, width, top, bottom, left, right, and beam may be numpy arrays,
+        single values, or None to disable. All values should be positive.
+        
+        If height is specified, it overrides top and bottom.
+        If width is specified, it overrides left and right.
+        """
+        GraphicsObject.__init__(self)
+        self.opts = dict(
+            x=None,
+            y=None,
+            height=None,
+            width=None,
+            top=None,
+            bottom=None,
+            left=None,
+            right=None,
+            beam=None,
+            pen=None
+        )
+        self.setOpts(**opts)
+        
+    def setOpts(self, **opts):
+        self.opts.update(opts)
+        self.path = None
+        self.update()
+        self.informViewBoundsChanged()
+        
+    def drawPath(self):
+        p = QtGui.QPainterPath()
+        
+        x, y = self.opts['x'], self.opts['y']
+        if x is None or y is None:
+            return
+        
+        beam = self.opts['beam']
+        
+        
+        height, top, bottom = self.opts['height'], self.opts['top'], self.opts['bottom']
+        if height is not None or top is not None or bottom is not None:
+            ## draw vertical error bars
+            if height is not None:
+                y1 = y - height/2.
+                y2 = y + height/2.
+            else:
+                if bottom is None:
+                    y1 = y
+                else:
+                    y1 = y - bottom
+                if top is None:
+                    y2 = y
+                else:
+                    y2 = y + top
+            
+            for i in range(len(x)):
+                p.moveTo(x[i], y1[i])
+                p.lineTo(x[i], y2[i])
+                
+            if beam is not None and beam > 0:
+                x1 = x - beam/2.
+                x2 = x + beam/2.
+                if height is not None or top is not None:
+                    for i in range(len(x)):
+                        p.moveTo(x1[i], y2[i])
+                        p.lineTo(x2[i], y2[i])
+                if height is not None or bottom is not None:
+                    for i in range(len(x)):
+                        p.moveTo(x1[i], y1[i])
+                        p.lineTo(x2[i], y1[i])
+        
+        width, right, left = self.opts['width'], self.opts['right'], self.opts['left']
+        if width is not None or right is not None or left is not None:
+            ## draw vertical error bars
+            if width is not None:
+                x1 = x - width/2.
+                x2 = x + width/2.
+            else:
+                if left is None:
+                    x1 = x
+                else:
+                    x1 = x - left
+                if right is None:
+                    x2 = x
+                else:
+                    x2 = x + right
+            
+            for i in range(len(x)):
+                p.moveTo(x1[i], y[i])
+                p.lineTo(x2[i], y[i])
+                
+            if beam is not None and beam > 0:
+                y1 = y - beam/2.
+                y2 = y + beam/2.
+                if width is not None or right is not None:
+                    for i in range(len(x)):
+                        p.moveTo(x2[i], y1[i])
+                        p.lineTo(x2[i], y2[i])
+                if width is not None or left is not None:
+                    for i in range(len(x)):
+                        p.moveTo(x1[i], y1[i])
+                        p.lineTo(x1[i], y2[i])
+                    
+        self.path = p
+        self.prepareGeometryChange()
+        
+        
+    def paint(self, p, *args):
+        if self.path is None:
+            self.drawPath()
+        pen = self.opts['pen']
+        if pen is None:
+            pen = pg.getConfigOption('foreground')
+        p.setPen(pg.mkPen(pen))
+        p.drawPath(self.path)
+            
+    def boundingRect(self):
+        if self.path is None:
+            return QtCore.QRectF()
+        return self.path.boundingRect()
+    
+