Path: csiph.com!fu-berlin.de!uni-berlin.de!news.dfncis.de!not-for-mail From: =?UTF-8?Q?Hans-Bernhard_Br=c3=b6ker?= Newsgroups: comp.graphics.apps.gnuplot Subject: Re: 3d plot.... turn 3d data into solid (i.e. plot boundary) Date: Sun, 13 Dec 2015 22:47:04 +0100 Lines: 20 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.dfncis.de njMAAJrDIylAJnQQtHDMhQj8Jh2/wzkFfJwXuWn4GGA3ZlGyO/cqbnE9x7 Cancel-Lock: sha1:XdHCDHG0GN3fBA3Rd+LZM1Q4OkY= User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 In-Reply-To: Xref: csiph.com comp.graphics.apps.gnuplot:3150 Am 13.12.2015 um 20:32 schrieb michael.o.rubinstein@gmail.com: > I have a collection of 3 dimensional points. Most of them are > interior to some complicated set. I would like to have gnuplot draw > just the boundary, assuming some level of smoothness for the > boundary, so that the interior points are not shown. Sorry, but, as specified here, that job would be impossible, because the result is under-defined. A cloud of points in 3D does not actually possess a boundary that gnuplot (or any program, for that matter) could possibly determine all by itself. Actually there is one surface which can be easily and unambiguously defined for a cloud of points: the convex hull; but it's unclear if that's the one you want. Either way this is not a plotting program's job. You need a 3D data processing tool or toolkit, and probably a whole lot of time to work with it.