Re: Printing multiple panels + multiple axis labels

[Gerard V. <ger...@gr...>]

On Mon, 23 Aug 2004 15:02:31 +0200
Stein Haaland <Ste...@is...> wrote:

> 
> 
> a) Printing multiple panels:
> I have a plot consisting of several panels, each is a qwtplot
> What is the best solution to print all panels on a single page ? 
> The QwtPlot::print() function prints a single panel and spits out 
> the page as far as I can see.
> 
It is straightforward to write your own print function which
prints an for instance an NxM array of plots by wrapping
void QwtPlot::print(QPainter *painter, const QRect &plotRect,
        const QwtPlotPrintFilter &pfilter) const
in a function which prints each plot in its own rectangle on
a paper.

The hard part is to make the scales line up, because the canvas layout
depends on how much is left over after the title and scales have been
layed out.

> 
> b) Multiple axis labels :
> Is there an easy way to add multiple axis labels, i.e., two or more 
> lines with axis labels. For my purpose I need both time and a 
> position along the x-axis
> 
> 
> An illustration (76kB *.png) showing this latter feature : 
>   http://www.issi.unibe.ch/~haaland/qwt/panels.png 
> 
> Code snips with my multi-panel declarations can be found on ;
>  http://www.issi.unibe.ch/~haaland/qwt/mpzoom.h
>  http://www.issi.unibe.ch/~haaland/qwtmpzoomplot.h
> 
> 
> sys = qwt 0.4.2, linux mdk 9.x, qt 3.3.0
>
You can draw a scale directly on paper using a QwtScaleDraw.

Again, you have to figure out how to match the extra scales with the
scale that is printed with the QwtPlot: realize that the QwtScaleDraw used
to draw the QwtScale of the QwtPlot is also an QwtDiMap. This gives you
the pixel coordinates of the QwtScale of the QwtPlot and you can
use that information to set the geometry of the QwtScaleDraws that you
will use for the extra scales.

Gerard