Commit graph

13 commits

Author SHA1 Message Date
Berthold Stoeger
e7907c494f statistics: convert chart to QQuickItem
It turns out that the wrong base class was used for the chart.
QQuickWidget can only be used on desktop, not in a mobile UI.

Therefore, turn this into a QQuickItem and move the container
QQuickWidget into desktop-only code.

Currently, this code is insane: The chart is rendered onto a
QGraphicsScene (as it was before), which is then rendered into
a QImage, which is transformed into a QSGTexture, which is then
projected onto the device. This is performed on every mouse
move event, since these events in general change the position
of the info-box.

The plan is to slowly convert elements such as the info-box into
QQuickItems. Browsing the QtQuick documentation, this will
not be much fun.

Also note that the rendering currently tears, flickers and has
antialiasing artifacts, most likely owing to integer (QImage)
to floating point (QGraphicsScene, QQuickItem) conversion
problems. The data flow is
QGraphicsScene (float) -> QImage (int) -> QQuickItem (float).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-10 15:16:52 -08:00
Berthold Stoeger
405e6b6b69 statistics: fix chart features: regression line and median/mean
The coordinates of these were calculated when creating the feature.
This is wrong, because the min/max values of the axes can change
on resize to get "nice" number. Therefore, recalculate after resizing.
This means that the general "LineMarker" class has to be split into
two classes, one for regression lines and one for median/mean
markers.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-06 12:31:22 -08:00
Berthold Stoeger
ab324ed769 statistics: paint custom grid
With removal of QtCharts' axes, the grid was lost. Readd it.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-06 12:31:22 -08:00
Berthold Stoeger
8dfa3f6db3 statistics: draw title of axes
Easy enough to implement, but one weirdness:
To get the height of the rotated text, one has to access the
width() member of the boundingRect. I'm not sure if that makes
sense, but so be it.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-06 12:31:22 -08:00
Berthold Stoeger
4ab9f1c6b0 statistics: replace QtCharts' axes
Replace by custom implementation, with the ultimate goal to
remove the QtCharts module. This doesn't yet display axis
titles or a grid.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2021-01-06 12:31:22 -08:00
Berthold Stoeger
90129aa26f statistics: render title
Since we want to get rid of QtCharts, we have to render our own
title. Simply keep around a QGraphicsSimpleTextItem and put in
the center of the chart. Define the borders to the scene as
constants.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2021-01-06 12:31:22 -08:00
Berthold Stoeger
23d781deba statistics: save chart in axis class
The chart was passed as argument to the function recalculating
the axis labels. Instead, pass the chart in the constructor of
the axes and save it. This gains us flexibility for the future:
There will be more functions that need to access the chart (e.g.
resizing of the axes).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-06 12:31:22 -08:00
Dirk Hohndel
ce0f64df2e stats: fix line segment intersection math
Linear algebra class was a while ago, but somehow this does look more
logical to me.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2021-01-04 11:20:51 -08:00
Dirk Hohndel
1f1d82b1b3 statistics: don't crash if the QCharts QML modules aren't found
We don't really give a user visible error message which is kind of a problem,
but at least we don't crash anymore.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2021-01-03 16:58:01 -08:00
Berthold Stoeger
bea289e314 statistics: clip regression line
A steep regression line would shoot out of the chart. Therefore,
clip to the y = minY and y = maxY lines.

QtGraphicsScene has its own clipping routines, but they are
very general, so let's do this trivial case by hand.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-03 13:56:05 -08:00
Berthold Stoeger
9759d5b21a statistics: add parentheses around percentage in horizontal bars
For better visual guidance, format labels as "count (percentage)"
in horizontal bar charts. In vertical bar charts two lines are used
anyway.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-03 13:56:05 -08:00
Berthold Stoeger
7b0455b4d8 statistics: reverse chart selection logic
The old ways was to select the chart first, then depending on
the chart choose the binning.

Willem says that it should work the other way round: select
the binning (or operation) and make the charts depend on
that.

I'm not arguing one way or the other, just note that the new
way is much more tricky, because it is easy to get unsupported
combinations. For example, there is no chart where the
first variable is unbinned, but the second axis is binned
or has an operation. This makes things distinctly more tricky
and this code still needs a thorough audit.

Since this is all more tricky, implement a "invalid" chart
state. Ideally that should be never shown to the user, but
let's try to be defensive.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-03 13:41:15 -08:00
Berthold Stoeger
995100a540 statistics: implement StatsView
The StatsView shows the chart described by the StatsState structure.
It is based on a QML ChartView. This should make it possible to
easily port to mobile. It does not include any of the UI around
the chart, viz. the variable and chart selection, etc.

The code checking for the statistical significance of the regression
line was written by Willem.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: willemferguson <willemferguson@zoology.up.ac.za>
2021-01-02 11:04:03 -08:00