From: Nicolas U. <n....@mx...> - 2007-05-25 13:27:46
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Hello, I have a little problem to plot a function with gnuplot. here the functions (phi will be include in HNimag): phi(x) =3D atan( sin(a * pi/2) / ((2*pi*tau*x)**(-a) + cos(a * pi/2))) HNimag(x) =3D de * sin(b * phi(x)) / ((1 + 2 * (2*pi*tau*x)**(a) * cos(a =20 * pi/2) + (2*pi*tau*x)**(2*a))**(b/2)) For b=3D0.99999999999999 the trace is correct (the curve I should get =20 when b=3D1). If u take b=3D1 the function make something wrong. Is it a bug? Greetings *********************************************** Nicolas Ubrig AG Prof.Dr. Rolf Pelster Universit=E4t des Saarlandes Geb. E2.6, Zi. 2.10 FR 7.2 Experimentalphysik Postfach 151150, D-66041 Saarbruecken, GERMANY Tel. ++49 - (0)681 - 302 - 3515 n....@mx... |
From: Mélanie G. <go...@as...> - 2011-04-01 09:32:38
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Hello, I'm a PhD student in Astrophysics in Belgium, finishing the thesis. I put the gnuplot 4.2 on my computer rather than gnuplot 4.0 because I needed the set object rectangle option. However, I found out that when using the ? operator to filter the data the lines don't appear. Only the points: plot 'file' u 4:(($3==3.0) ? $6 : 1/0) w lp lw 3 --> only the points appear in my graph plot 'file' u 4:(($3==3.0) ? $6 : 1/0) w l lw 3 --> nothing appear... Could you help me? I couldn't find any information about this on internet, I already search a lot, is it a bug? Is it still present in version 4.4? Thank you in advance, Mélanie -- Mélanie Godart go...@as... Institut d'Astrophysique et de Géophysique (Bât B5c, bureau 1/5) 17, allée du 6 Août Tel: 32-4-3669762 Sart Tilman, B-4000 Liège Fax: 32-4-3669737 ________________________________________________________________ |
From: Jérôme B. <jer...@gm...> - 2011-04-01 18:59:39
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Hello, As far as I can test with gnuplot 4.4 patchlevel 2 1) Your file does not contain any 3.0 value in the third column. However it contains plenty of 3.0E6, so I changed the condition accordingly. 2) the ? operator does work, you can see this by replacing 1/0 by a numerical value or by $6. I would say he guilty is 1/0 which prevents the dots to be connected between the point before and the point after the ignored one. Considering I read this mailing list for months and never saw any answer to a question (only lots of spam), I do not expect your bug to find a solution anytime soon (please, Gnuplot developers, prove me wrong and reply to this mail!). So in your case, I would use a preprocessing command : $ awk '{if ($3==3.00000000E+06) print $0 }' file > file_with_3E6 Best regards Jérôme Borme 2011/4/1, Mélanie Godart <go...@as...>: > Hello, > > I'm a PhD student in Astrophysics in Belgium, finishing the thesis. I > put the gnuplot 4.2 on my computer rather than gnuplot 4.0 because I > needed the set object rectangle option. > However, I found out that when using the ? operator to filter the data > the lines don't appear. Only the points: > > plot 'file' u 4:(($3==3.0) ? $6 : 1/0) w lp lw 3 --> only the points appear > in my graph > plot 'file' u 4:(($3==3.0) ? $6 : 1/0) w l lw 3 --> nothing appear... > > Could you help me? I couldn't find any information about this on internet, I > already search a lot, is it a bug? > Is it still present in version 4.4? > > Thank you in advance, > > Mélanie > > > > -- > Mélanie Godart go...@as... > Institut d'Astrophysique et de Géophysique (Bât B5c, bureau 1/5) > 17, allée du 6 Août Tel: 32-4-3669762 > Sart Tilman, B-4000 Liège Fax: 32-4-3669737 > ________________________________________________________________ > > > ------------------------------------------------------------------------------ > Create and publish websites with WebMatrix > Use the most popular FREE web apps or write code yourself; > WebMatrix provides all the features you need to develop and > publish your website. http://p.sf.net/sfu/ms-webmatrix-sf > _______________________________________________ > gnuplot-bugs mailing list > gnu...@li... > https://lists.sourceforge.net/lists/listinfo/gnuplot-bugs > |
From: <HBB...@t-...> - 2007-05-25 18:18:43
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Nicolas Ubrig wrote: > I have a little problem to plot a function with gnuplot. Actually, the problem is not with functions, or plotting, but with expression evaluation. Check the third paragraph of 'help expressions' to understand why (b/2) changes behaviour if you make b=1, as opposed to b=1.0. |