pyqtgraph/pyqtgraph — pull request #58 by JNevrly (2014-03-16 14:16:37+00:00)
Title: PlotDataItem downsampling calculation fix

There is a zero-division problem in PlotDataItem in case when automatic downsampling is enabled before a Plot and the corresponding ViewBox is properly set-up within it's container (in such case, the ViewBox.width is 0). This is the simplest fix.