Re: noob questions :)

*To*: mathgroup at smc.vnet.net*Subject*: [mg87374] Re: noob questions :)*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Wed, 9 Apr 2008 05:53:02 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <ftfegg$bsg$1@smc.vnet.net>

markus.mooslechner at chello.at wrote: > hi everyone! > > first of all i would like to introduce myself. being an artist i am mainly engaged in the visualization of chaotic systems such as iterated function systems or strange attractors from experimental data. i consider myself a completely mathematica noob (willing to learn ::)) i got introduced to mathematica by a friend who works in the math institute at our local university (hence, that's where i spent most of my recent time ... lol). to get myself started with the project i have in mind i could use some help, which i have not found in the databases yet: > > - how can i tell mathematica to import a three-column (x,y,z) txt file and do a 3d plot from the values. i already messed with the ListPlot3D command , unfortunately to no avail. the file containing the experimental data looks something like this: > point,x,y,z > 1,34,21,45 > 2,32,53,76 > 3,12,23,43 > 4,45,21,87 > 5,65,76,87 > etc Say that you have imported (Import[...]) your experimental data into the variable impt. impt {{1, 34, 21, 45}, {2, 32, 53, 76}, {3, 12, 23, 43}, {4, 45, 21, 87}, {5, 65, 76, 87}} Since the first column of the matrix (or the first entry of each quadruple if you want) contains only a line number, we can safely discard it to keep only the {x, y, z} values. data = impt[[All, 2 ;; 4]] {{34, 21, 45}, {32, 53, 76}, {12, 23, 43}, {45, 21, 87}, {65, 76, 87}} We can, now, use ListPlot3D. ListPlot3D[data] > - how can i then tell mathematica to color certain values from this data list with a color from my choice? eg: color the values X "red" (X could be something like the mean value of the entire list) You could use option such as *Epilog*. <snip> Regards, -- Jean-Marc