Quote Originally Posted by Seamus View Post
How can I hide the horizontal gaps in a candlestick/bar chart (I've marked this with 'Weekend' in the screenshot provided)?
You can subclass QwtPlotCurve and draw whatever you want (and not draw whatever you want) by reimplementing draw* methods.

Which 'Qwt*Data' classes are best suited to storing calculations made from the candlesticks samples that are to be plotted over or below the chart the calculation formula need to look back (i.e a Simple Moving Average, or MACD)?
I did it this way that I had a QAbstractItemModel storing all the data and I had a subclass of QwtSeriesData<QPointF> that calculated and cached desired MA samples from the main data store.

What is the proper way to handle the last candle in the plot, the last candle changes when the markets are open. At the moment I'm using two trading curves, one for finished bars one for open bar. I had to prepend a fake candle to plot the open bar as Qwt wasn't handling a data-set with only one sample properly.
I don't really understand what you mean here. But you can again override draw* methods from QwtPlotCurve and draw what you want. I was reading open/close/min/max data from the abstract item model associated with my series data but you can also store the data directly in QwtSeriesData if you use a structure containing x and those four y values. Then if the open price is lower than 0 then just don't draw it.