plots.py 文件源码

def _update(self):
        if not self._sink:
            return False

        # Read and format data.
        data, timestamps = self._sink.retrieveData(length=self._frameSize)
        if not data:
            return
        sri = self._sink.sri
        data = self._formatData(data, sri)

        # If xdelta changes, update the X and Y ranges.
        if self._sink.sriChanged():
            # Update the X and Y ranges
            x_min, x_max = self._getXRange(sri)
            y_min, y_max = self._getYRange(sri)
            self._image.set_extent((x_min, x_max, y_max, y_min))

            # Preserve the aspect ratio based on the image size.
            x_range = x_max - x_min
            y_range = y_max - y_min
            self._plot.set_aspect(x_range/y_range*self._aspect)
            self._xdelta = sri.xdelta

        # Resample data from frame size to image size.
        height, width = self._imageData.shape
        indices_out = numpy.linspace(0, len(data)-1, width)
        indices_in = numpy.arange(len(data))
        data = numpy.interp(indices_out, indices_in, data)

        # Store the new row and update the image data.
        self._imageData[self._row] = data
        self._image.set_array(self._imageData)

        # Advance row pointer
        self._row = (self._row + 1) % height

        return True