How can I tell which scale is used on an axis?

[steve123]

Hi! I've created a Qwt Plot with the ability to switch between log scale and arithmetic scale. I'd like to be able to exclude any 0s in the data when I am in log scale mode. I set the scale this way:

plot->setAxisScaleEngine(QwtPlot::yLeft, new QwtLog10ScaleEngine());

plot->setAxisScaleEngine(QwtPlot::yLeft, new QwtLog10ScaleEngine());

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Then later on when data comes in, I need to filter out the zeros. How can I figure out which scale engine is currently in use? Thanks!