[Interest] [QtCharts] Logarithmic QDateTimeAxis
chgans at gna.org
Wed Jul 13 13:46:56 CEST 2016
On 28 June 2016 at 07:55, Thompson, Adam B. <thompsonab at ornl.gov> wrote:
> The software package I co-develop at work is dependent on Qt 4.8, but we plan to move to Qt 5
> when we have time/funding. We currently depend on a third-party plotting package for our 2D data
> visualization, but we'd like to be able to use QtCharts when we upgrade.
> Some of our data sets are time-dependent and are often extrapolated hundreds or thousands of
> years in the future. As such, a logarithmic time scale would be quite useful, if not necessary to view
> the data in a truly meaningful manner.
Why not use a plain QLogValueAxis for your X axis, if you're talking
thousand of years, i guess you don't need month, day, hours, minutes,
... on your X axis, do you? Do you need to take into account leap
year, leap seconds? Is there a mathematical definition of
QLogValueAxis with just years should do the job. But maybe i'm missing
Looking at the source in qt5/qtcharts/src/charts/axis/datetimeaxis and
qt5/qtcharts/src/charts/axis/logvalueaxis doesn't show complicated
code. So this seems to be doable "easily".
> Can anyone provide guidance on properly extending QDateTimeAxis (, QLogValueAxis, or QAbstractAxis) to provide a logarithmic time scale as I've described?
> Adam Thompson
> Computer Scientist, Nuclear Engineering
> Oak Ridge National Laboratory
> Interest mailing list
> Interest at qt-project.org
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