I was coninced that that rather than doing an order of
magnitude estimate of the confidence region it's better
to have the correct concave shapes that indicate the
95% confidence level for the regression line.
It also turned out that the previous expression was
missing a factor of 1/sqrt(n).
Signed-off-by: Robert C. Helling <helling@atdotde.de>
The goodness of fit of a regression line is the percentage
of the variance of the y values that is explained by the
dependence on the x values.
Set the alpha value of the regression line to this goodness
of fit.
Further, set the width of the regression line to a standard
deviation of the values from the regression line valies.
Signed-off-by: Robert C. Helling <helling@atdotde.de>
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>
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>
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>
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>
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>
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>
