x = linspace(-9, 9, 1000)
y = cos(x)
y.putProperty( QDataSet.FILL_VALUE, -1e31 )
y[50:60] = -1e31

y= y[40:70]
x= x[40:70]

setCanvasSize(800, 600)

plot( x, y, renderType='fillToZero', symbolSize=10, xrange=[-8.5,-6.5] )
plot( 1, x, y, renderType='scatter', symbolSize=20, xrange=[-8.5,-6.5] )