Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!nx01.iad01.newshosting.com!newshosting.com!69.16.185.11.MISMATCH!npeer01.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!postnews.google.com!l27g2000prd.googlegroups.com!not-for-mail From: fearless_fool Newsgroups: comp.graphics.apps.gnuplot Subject: splot with variably translucent points Date: Thu, 22 Sep 2011 14:47:31 -0700 (PDT) Organization: http://groups.google.com Lines: 24 Message-ID: <055a7cbb-cb4d-4035-8c58-e293e18246c3@l27g2000prd.googlegroups.com> NNTP-Posting-Host: 108.0.108.79 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: posting.google.com 1316728051 12187 127.0.0.1 (22 Sep 2011 21:47:31 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Thu, 22 Sep 2011 21:47:31 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: l27g2000prd.googlegroups.com; posting-host=108.0.108.79; posting-account=3scLpQoAAAAxMAAkXxP_UPjHW3n0SOzM User-Agent: G2/1.0 X-Google-Web-Client: true X-Google-Header-Order: HNKRUAELSC X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.220 Safari/535.1,gzip(gfe) Xref: x330-a1.tempe.blueboxinc.net comp.graphics.apps.gnuplot:596 I want to visualize a minimization problem over three input variables and one result. With only two input variables, the visualization problem would be trivial. My thought is to use splot to plot 3D points, with the most opaque point(s) representing the minima, and more translucent points as it deviates from the minima. This way, you should be able to see a cluster of dark points near the minimum. How do I set the transparency of each point from the input data? Without variable transparency, I've got something as follows. I'd like to use $4 to control the transparency. =========== set terminal pngcairo truecolor set view 60, 136, 1.22, 1.26 splot "-" using 1:2:3 with points pointtype 7 pointsize 2 linecolor rgb '#444444' 3 -4 -4 37.767 3 -4 -6 37.744 ... end ===========