*** Fons Rademakers wrote : > > Just a clarification. > > Matrices use internally, for efficiency reasons, column > wise storage. This however is completely hidden from the > user. The element m(i,j) is the element at the i-th row > and j-th column (like in math and C/C++). The issue is: is, > by default, the first element m(1,1) or m(0,0). Currently > I've implemented (0,0) as first element. For example: > > TMatrix m1(4,20); // m1(0,0) ... m1(3,19), same as > TMatrix m2(0,3,0,19); // m2(0,0) ... m2(3,19) > TMatrix m3(1,4,1,20; // m3(1,1) ... m3(4,20) > > It could be: > > TMatrix m4(4,20); // m4(1,1) ... m4(4,20) > > I've seen a number of packages using 1 as lowerbound > and a number of packages using 0. > > Let me know your preference. > > -- Fons. > Hi Fons, This is exactly the way I used it for the ALICE stuff, and again I prefer the m(1,1) to be the first element in order to be in line with math books, formulas and common sense. Cheers, Nick. *----------------------------------------------------------------------* Dr. Nick van Eijndhoven Department of Subatomic Physics email : nick@fys.ruu.nl Utrecht University / NIKHEF tel. +31-30-2532331 (direct) P.O. Box 80.000 tel. +31-30-2531492 (secr.) NL-3508 TA Utrecht fax. +31-30-2518689 The Netherlands WWW : http://www.fys.ruu.nl/~nick Office : Ornstein lab. 172 ---------------------------------------------------------------------- tel. +41-22-7679751 (direct) CERN PPE Division / ALICE exp. tel. +41-22-7675857 (secr.) CH-1211 Geneva 23 fax. +41-22-7679480 Switzerland CERN beep : 13+7294 Office : B 160 1-012 *----------------------------------------------------------------------*
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