+
+ -----------------------------------------------
+
+ Explanation on integrals in the TPC region
+ GetTPCInt(xyz,b) and GetTPCRatInt(xyz,b) give integrals from point (x,y,z) to point (x,y,0)
+ (irrespectively of the z sign) of the following:
+ TPCInt: b contains int{bx}, int{by}, int{bz}
+ TPCRatInt: b contains int{bx/bz}, int{by/bz}, int{(bx/bz)^2+(by/bz)^2}
+
+ The same applies to integral in cylindrical coordinates:
+ GetTPCIntCyl(rphiz,b)
+ GetTPCIntRatCyl(rphiz,b)
+ They accept the R,Phi,Z coordinate (-pi<phi<pi) and return the field
+ integrals in cyl. coordinates.
+
+ Thus, to compute the integral from arbitrary xy_z1 to xy_z2, one should take
+ b = b1-b2 with b1 and b2 coming from GetTPCInt(xy_z1,b1) and GetTPCInt(xy_z2,b2)
+
+ Note: the integrals are defined for the range -300<Z<300 and 0<R<300