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Re: [Gnuplot-info] Question on Plots on Non-regular Grid
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From: Mauricio G. <ga...@fc...> - 2007-07-02 17:11:42
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Dears Some examples relative to surface representations of non-regular grid using gnuplot can be found in the following webpage: http://www2.prudente.unesp.br/dcartog/galo/gnuplot/gnu_exemplos2.htm M. Galo > Hello, > And thanks for your suggestion. > It seems there is a problem, though. > Somehow gnuplot does not understand that it is working on a cylinder > cross section. > If I try: > > set dgrid3d 10,10 > set hidden3d > set pm3d > splot "example.txt" u 1:2:3 with lines > > where "example.txt" is the file containing the data as shown in the > email, what I get is a rectangular grid. Is it simply an artifact due > to the low number of grid points or am I doing something wrong? > Many thanks > > Lorenzo > > > >> Message: 6 >> Date: Mon, 2 Jul 2007 07:02:09 -0700 (PDT) >> From: Thomas Sefzick <t.s...@fz...> >> Subject: Re: [Gnuplot-info] Question on Plots on Non-regular Grid >> To: gnu...@li... >> Message-ID: <113...@ta...> >> Content-Type: text/plain; charset=us-ascii >> >> >> a contour plot is not so easy unless you have your data on a grid. >> re-binning a few data points into a grid with 'dgrid3d' doesn't work. >> >> so, either you have a reasonable number of data points - so many, >> that 'set dgrid3d' works - or you do the re-binning (= filling a >> 2d-histogram) >> outside of gnuplot. >> or, for a very low number of data points, a 'poor man's' solution could >> be: >> >> set xrange [-1:1] >> set yrange [-1:1] >> set view map >> set mapping cyl >> splot 'datafile' using 1:3:2 with points pointtype 5 pointsize 3 palette >> >> >> Lorenzo Isella wrote: >> > >> > Dear All, >> > I am fairly new to data plotting and visualization. >> > My problem should be simple, but it is not straightforward to tackle >> in >> > R or Python. >> > On the cross section of a pipe (i.e. on a circle) I have a temperature >> > reading of the kind: T=T(r,theta). >> > I would like to make a 2D contour plot using colors such that one can >> see >> > that the domain where I am plotting is actually a circle. >> > Furthermore, I do not have necessarily an equally spaced grid. >> > For instance, let me consider the case of 5 theta's and 7 radial >> > position and consequently 35 values of T (just a simple test): >> > >> > theta >> > R T >> > 0.000000000000000000e+00 0.000000000000000000e+00 >> 5.459815003314423620e+01 >> > 0.000000000000000000e+00 1.666666666666666574e-01 >> 4.853828855239110851e+01 >> > 0.000000000000000000e+00 3.333333333333333148e-01 >> 4.315101251901344881e+01 >> > 0.000000000000000000e+00 5.000000000000000000e-01 >> 3.836167151642037965e+01 >> > 0.000000000000000000e+00 6.666666666666666297e-01 >> 3.410390059527122020e+01 >> > 0.000000000000000000e+00 8.333333333333332593e-01 >> 3.031870066752165016e+01 >> > 0.000000000000000000e+00 1.000000000000000000e+00 >> 2.695362096775039973e+01 >> > 1.570796326794896558e+00 0.000000000000000000e+00 >> 2.396203225329512776e+01 >> > 1.570796326794896558e+00 1.666666666666666574e-01 >> 2.130248067207563523e+01 >> > 1.570796326794896558e+00 3.333333333333333148e-01 >> 1.893811334477913277e+01 >> > 1.570796326794896558e+00 5.000000000000000000e-01 >> 1.683616770181326316e+01 >> > 1.570796326794896558e+00 6.666666666666666297e-01 >> 1.496751749887080329e+01 >> > 1.570796326794896558e+00 8.333333333333332593e-01 >> 1.330626922033307302e+01 >> > 1.570796326794896558e+00 1.000000000000000000e+00 >> 1.182940327795447999e+01 >> > 3.141592653589793116e+00 0.000000000000000000e+00 >> 1.051645503298913731e+01 >> > 3.141592653589793116e+00 1.666666666666666574e-01 >> 9.349231221746512333e+00 >> > 3.141592653589793116e+00 3.333333333333333148e-01 >> 8.311557855141172624e+00 >> > 3.141592653589793116e+00 5.000000000000000000e-01 >> 7.389056098930650407e+00 >> > 3.141592653589793116e+00 6.666666666666666297e-01 >> 6.568943029058285532e+00 >> > 3.141592653589793116e+00 8.333333333333332593e-01 >> 5.839854501207304871e+00 >> > 3.141592653589793116e+00 1.000000000000000000e+00 >> 5.191687680104649871e+00 >> > 4.712388980384689674e+00 0.000000000000000000e+00 >> 4.615461046534314882e+00 >> > 4.712388980384689674e+00 1.666666666666666574e-01 >> 4.103189942205120566e+00 >> > 4.712388980384689674e+00 3.333333333333333148e-01 >> 3.647775927922803252e+00 >> > 4.712388980384689674e+00 5.000000000000000000e-01 >> 3.242908421924544982e+00 >> > 4.712388980384689674e+00 6.666666666666666297e-01 >> 2.882977255397825012e+00 >> > 4.712388980384689674e+00 8.333333333333332593e-01 >> 2.562994933482758420e+00 >> > 4.712388980384689674e+00 1.000000000000000000e+00 >> 2.278527524544009530e+00 >> > 6.283185307179586232e+00 0.000000000000000000e+00 >> 2.025633220058637107e+00 >> > 6.283185307179586232e+00 1.666666666666666574e-01 >> 1.800807713756398032e+00 >> > 6.283185307179586232e+00 3.333333333333333148e-01 >> 1.600935643142084031e+00 >> > 6.283185307179586232e+00 5.000000000000000000e-01 >> 1.423247420534685892e+00 >> > 6.283185307179586232e+00 6.666666666666666297e-01 >> 1.265280855439646635e+00 >> > 6.283185307179586232e+00 8.333333333333332593e-01 >> 1.124847036463023642e+00 >> > 6.283185307179586232e+00 1.000000000000000000e+00 >> 1.000000000000000000e+00 >> > >> > >> > >> > How would you plot them in order to have a 2D-color plot where one can >> > understand we are working on a circle (well, maybe it will look like >> > something different since I have only a few grid points, but the aim >> > is clear, I hope)? >> > Despite its simplicity, this has been taking me a long time and I am >> not >> > done yet. Someone has recently suggested to learn VTK, but it may be >> too >> > much for what I have in mind. >> > Anyone who can give me a simple script to read that data and get a >> > contour plot on a pipe's cross section would help me a lot (I am sure >> > it must amount to a few lines). >> > Kind Regards >> > >> > Lorenzo >> > >> > ------------------------------------------------------------------------- >> > This SF.net email is sponsored by DB2 Express >> > Download DB2 Express C - the FREE version of DB2 express and take >> > control of your XML. No limits. Just data. Click to get it now. >> > http://sourceforge.net/powerbar/db2/ >> > _______________________________________________ >> > Gnuplot-info mailing list >> > Gnu...@li... >> > https://lists.sourceforge.net/lists/listinfo/gnuplot-info >> > >> > >> >> -- >> View this message in context: >> http://www.nabble.com/Question-on-Plots-on-Non-regular-Grid-tf4009454.html#a11394474 >> Sent from the Gnuplot - User mailing list archive at Nabble.com. >> >> >> >> >> ------------------------------ >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by DB2 Express >> Download DB2 Express C - the FREE version of DB2 express and take >> control of your XML. No limits. Just data. Click to get it now. >> http://sourceforge.net/powerbar/db2/ >> >> ------------------------------ >> >> _______________________________________________ >> Gnuplot-info mailing list >> Gnu...@li... >> https://lists.sourceforge.net/lists/listinfo/gnuplot-info >> >> >> End of Gnuplot-info Digest, Vol 14, Issue 1 >> ******************************************* >> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Gnuplot-info mailing list > Gnu...@li... > https://lists.sourceforge.net/lists/listinfo/gnuplot-info > |
