Question posted to the QtCentre / Qwt forum. 4-05-2017.
Dense Qwt curves with dotted or dashed line style generally look solid.
http://www.qtcentre.org/threads/68094

Note [4-20-2017]: This problem has been addressed for RiverWare 7.1. This is described on this webpage:

The images below (expanded X2) show one "Step" curve and one "Line" curve with many points. This sequence of seven images progressively zooms in. Point symbols are turned on half-way through to show the density of the series data. We're using Qwt 6.1.3 and Qt 5.5.1 on Windows.

Animated sequence of seven frames:

DenseTestThree.gif

The individual frames:

DenseTestThree_01.png

DenseTestThree_02.png

DenseTestThree_03.png

DenseTestThree_04.png

DenseTestThree_05.png

DenseTestThree_06.png

DenseTestThree_07.png

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