Re: [ROOT] ROOT 20 times slower

From: Timothy E. Miller (tim@bnl.gov)
Date: Wed Jan 23 2002 - 04:18:47 MET 

On Tue, 2002-01-22 at 21:48, Kalen Martens wrote:
> I've just had a thought on this. Looking in TVector3.h, the constructor
> looks like:
> 
> TVector3(Double_t x = 0.0, Double_t y = 0.0, Double_t z = 0.0);
> 
> The variables Pxpar[ii], etc, are of type Float_t. Is this the problem? I
> can't find anywhere that tells me either that ROOT does an implicit
> conversion, or how to do a conversion explicitly between these data types,
> so I can't check it myself. 

Following the theme of "The X-Files", trust no compiler.
Do the conversion yourself with some trivial typecasting.

i.e.
   TVector3  p_muon((Float_t)(Pxpar[ii]), (Float_t)(Pypar[ii]),
                    (Float_t)(Pzpar[ii]));

(the extraneous () are my own personal preference to make
 sure I know what I'm converting)

-- 
  PHB:  I wonder what they know that I don't?
Wally:  Now there's a hole with no bottom in it...

pub  1024D/35B93695 2001-10-11 Tim Miller <tim.miller@vanderbilt.edu>
Key fingerprint = 041D E801 6EC8 F0A4 10C3  3E74 295F 004F 35B9 3695
pub  1024R/B54CD57F 2001-12-21 Timothy E. Miller <tim@bnl.gov>
Key fingerprint = 61 D6 4C 6B 86 BD 34 72  00 17 EE 46 1F B0 A2 0B

This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:39 MET