Hi Tommaso, I looked closer at your examples. I agree with you that the first one transform the following labels: -80 -60 -40 -20 0 20 40 60 80 into: 80 60 40 20 0 -20 -40 -60 -80 But, seems to me the 2nd example transform: 0 20 40 60 80 100 120 140 160 180 into: 90 70 50 30 10 -170 -150 -130 -110 -90 Which, I guess, is not what you want. I think you did a mistake in your 2nd example. Cheers, Olivier On Tue, 9 Mar 2004, Tommaso Chiarusi wrote: > > Hello everybody: > > OS Linux RH 9 > ROOT 3.10/02 16 December 2003 > > well, I need to reset the labels onto an histogram. > It has the x axis which ranges from 0 to +180 > I like it to span from +90 to -90 (yes from positive to negative > like 90 80 70..10 0 -10 ... -80 -90). > > So decided to > TGaxis method together with a function > > > So I've written the function: > > double funz(double *x,double *par) > { > double fu=0; > fu = -x[0]; > return fu; > } > > and in the body of the macro, > > TF1 *f = new TF1("f",funz,-90,90,0); > TGaxis *tga = new TGaxis(0,0,180,0,"f",510); > tga->Draw(); > > and it works! > > note that the spanning of the new scale is independent from the original > range. > ----- > THE QUESTION: > > Why the following doesn't give the same result? > > I redefine the function, > > double funz(double *x,double *par) > { > double fu=0; > if(x[0]<=90) fu = 90 -x[0]; > if(x[0]>90) fu = x[0]-270; > > return fu; > } > > and in the body of the macro, > > TF1 *f = new TF1("f",funz,0,180,0); > TGaxis *tga = new TGaxis(0,0,180,0,"f",510); > tga->Draw(); > > note the different range for f > > Best regards, Tommaso > > P.S. > is this mailing list hard-contamined by spam? > is it true that it will be removed by the CERN mailing list? > > > > -- Org: CERN - European Laboratory for Particle Physics. Mail: 1211 Geneve 23 - Switzerland Mailbox: J25910 E-Mail: Olivier.Couet@cern.ch Phone: +41 22 7676522 WWW: http://cern.ch/Olivier.Couet/ Fax: +41 22 7677155
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:06 MET