From: Pawel C. S. S. <pa...@gm...> - 2007-04-15 07:44:25
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Hi. the plot splot '+' 1:2:(sin($1)*$2*$2):(cos($2)*$1*$1) with vectors is not working. I not found any splot with vectors example in the demo files: bash: grep splot * | grep vectors But what I need is a 2d plot with vectors, the same as gnuplot>plot 'mydataField.dat' using 1:2:3:4 with vectors where in the file 'mydataField.dat' I have x y sin(x)*y^2 cos(y)x^2 calculated for all points. I would like to get the same using something like special functions: gnuplot>plot '+' using 1:2:(sin($1)*$2*$2):(cos($2)*$1*$1) with vectors Pawel Szklarz. 2007/4/14, Ethan A Merritt <merritt@u.washington.edu>: > On Saturday 14 April 2007 10:29, Pawel Cesar Sanjuan Szklarz wrote: > > Hi > > > > I am interested in add a feature do gnuplot: 2d vector fields from > > R^2->R^2 functions > > > > example: > > gnuplot>plot (sin(x)*y^2,cos(y)x^2) with 2dVectorField > > Please have a look at the very recent feature added to the cvs version: > > gnuplot> help special-filenames > There are three filenames that have a special meaning: '', '-', and '+'. > The special filename '+' is a mechanism to allow the full range of > `using` specifiers and plot styles with in-line functions. Normally a > function plot can only have a single y (or z) value associated with each > sampled point. The pseudo-file '+' treats the sampled points as columns > 1 (plot) or 1 and 2 (splot), and allows additional column values to be > specified via a `using` specification, just as for a true input file. > Example: > plot '+' using ($1):(sin($1)):(sin($1)**2) with filledcurves > > > You may be able to use this new mechanism to do your plotting. > Or maybe not. I'm not sure I understand what is the intended output > from your example. Is it a set of vectors, with each vector connecting > (x,y) to (sin(x)*y^2, cos(y)*x^2) ? That would be something like > splot '+' 1:2:(sin($1)*$2*$2):(cos($2)*$1*$1) with vectors > You may have to change "set isosamples" first. > > Of course Octave doesn't yet know about this option, but I'm sure > that can be fixed. > > > > > > > I know that it is possible to create a datafile with the information > > about the vector field, but it can be nice to make zoom and don't > > worry about the data density in the datafile. > > > > I would like to add another feature: I would like to use octave (for > > example) to calculate the value of some function. > > My proposition is not to run octave many times, but to create a > > children process and send/recibe values by PIPES, example: > > > > gnuplot>open calculator 'myCulculatorProgram' > > now gnuplot forks and create a children process > > "system('myCulculatorProgram')" and is ready to use that program to > > calculate something (open 2 pipes gnuplot<-->Mycalculator) > > gnuplot>plot calculator('myExternalFunctionName',x,y) > > To calculate the value of > > calculator('myExternalFunctionName',x,y) > > gnuplot send data by the pipe to the children process and white for > > the results in another pipe. > > > > This feature can by really great, octave is what I need, but with this > > mechanism it is possible even to send SOAP request to some special > > mega-calculation-server or what ever. > > > > I have ready some code for this feature, but i would like to know: > > --can be this useful? > > -- it is possible to make something equivalent with gnuplot in some other way > > And if this is a new feature, then: > > -- what format to use for this features (represent R2->R2 functions, > > and the external calculator) > > -- how to submit code to CVS > > > > Thanks > > > > ------------------------------------------------------------------------- > > 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-beta mailing list > > gnu...@li... > > https://lists.sourceforge.net/lists/listinfo/gnuplot-beta > > > > -- > Ethan A Merritt > Biomolecular Structure Center > University of Washington, Seattle 98195-7742 > |