You'll have to write code, but it's not that hard.
Pens don't know about where they are on the painted surface.
Painters do know where they are drawing, and they use the pen, so the code using the painter has to do it.
QPainter painter
double range = max-min;
for (const auto &segment :segments) {
double y_hue=(((segment.y1+segment.y2)/2) - min) / range;
QColor color= QColor::fromHSFV( y_hue,1,1);
painter.setPen(color);
painter.drawLine(segment.x1, segment.y1, segment.x2, segment.2);
}
or somehing like that.
Sent: Thursday, June 21, 2018 at 10:20 AM
From: "Massimiliano Maini" <[email protected]>
To: [email protected]
Cc: [email protected]
Subject: Re: [Interest] Plotting 2d line with color depending on value (like colormap)
From: "Massimiliano Maini" <[email protected]>
To: [email protected]
Cc: [email protected]
Subject: Re: [Interest] Plotting 2d line with color depending on value (like colormap)
Thanks Uwe and Jason.
At the moment I'm using a 3rd party library (http://www.qcustomplot.com/): very handy but doesn't seem to support what I need.
I was wondering if I the feature could be easily added as it is easily doable in Qt (as in "there's a special QPen to do this") or not.
Looks like the answer is NO.
Regards,
On Thu, 21 Jun 2018 at 15:42, Jason H <[email protected]> wrote:
It's a simple mapping of y value to "H" in a HSV space over the normalized range of values.To do it in a bitmap is easy, to do it as a line like you 'd want on a vector plot, i'd take the y midpoint value of the segment and use that for the pen color for the whole line, choosing a sensible number of points.Sent: Thursday, June 21, 2018 at 5:51 AM
From: "Massimiliano Maini" <[email protected]>
To: [email protected]
Subject: [Interest] Plotting 2d line with color depending on value (like colormap)Hi all,_______________________________________________ Interest mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/interestI'd need to do something like this: https://imgur.com/MLAEuadI have a set of (x,y,z) data points and want to plot them on a usual 2d plot ( x and y values), but with the line color depending on the z values (colormap).How can this be achieved in Qt ?Max.
_______________________________________________ Interest mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/interest
