Re: [Gnuplot-info] kdensity plot not filled with filledcurves y=0

[Ethan M. <merritt@u.washington.edu>]

On Monday, 04 July 2016 11:08:52 AM Ethan A Merritt wrote:
> On Monday, 04 July 2016 04:11:44 PM Grothausmann, Roman Dr. wrote:
> > On 01/07/16 19:10, Ethan Merritt wrote:
> > > I do not know why the filledcurves style is failing in conjunction with
> > > smoothing, but a work-around is to plot  first to a datablock and then plot
> > > the smoothed curve in a separate step:
> > >
> > > set table $SMOOTHED
> > > plot $original_data using col:(weight) smooth kdensity bandwidth sigma
> > > unset table
> > > plot $SMOOTHED using 1:2 with filledcurves y=0
> > 
> > Many thanks Ethan for the quick reply and the work-around. I got it working 
> > (https://github.com/romangrothausmann/gnuplot/blob/5f513bf1cf81c1709ff450e2830c8c59b76d2c80/hist-ar%2Bkd.gp) 
> > 
> > but the resulting plot of the "filled table" is kind of "ragged" when saved to 
> > SVG. See attached compressed SVG for the test data created with:
> > gnuplot -e "datafile='test.dat'; outfile='test.svg'; bin=10; sigma=3.5; xmin=0; 
> > xmax=180; col=1; sep=','; xlabel='test'" hist-ar+kd.gp
> > 
> > Any idea how to avoid this raggedness?
> 
> Sorry, that is in part a consequence of the work-around.
> 
> I think the issue is that you are using a partially transparent fill.
> The intended behaviour (that isn't working) is to draw the entire curve
> as one large semi-transparent area.  The workaround causes it to be
> drawn instead as a series of adjacent semi-transparent quadrilaterals.
> Whenever there is an imperfect join between two adjacent quadrilaterals
> due to coordinate round-off, there can be a glitch in rendering.

By the way:  the glitch is in the rendering program, not the svg file per se.
So changing the scale slightly or using a different viewing program may
reduce or exacerbate the problem.

	Ethan


> 
> This glitch is more evident when the fill area is transparent, so one
> thing you could try is to make the fill style "solid" rather than 
> "transparent solid".
> 	
> Ethen

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