Last significant change: 2004/03/11
NB: This chapter is appropriate for users of MINOS software dated prior to 2006/09/19, or for those using MINOS software more recent than that but who have configured the default behavior off in favor of restoring the geometry build used previous to this date. The last release prior to this date was R1.24.0. For R1.24.1 or later, the information in this chapter has been superceded by that in the next chapter entitled Geometry.
The UgliGeometry package provides services for managing the physical placement of detector elements in 3-space.
The user does not work directly with a UgliGeometry object, but instead works through a UgliGeomHandle. These UgliGeomHandles are lightweight proxy objects that do little work of any substance. During the creation of a UgliGeomHandle a loan pool of real UgliGeometry objects searched for an appropriate object; if no match exists one will be created. The UgliGeomHandle then forwards member function calls to the correct UgliGeometry. This allows the UgliGeomHandle to share the larger underlying collection of information and it lowers the overhead of the creation and deletion of UgliGeomHandles.
This approach also allows the UgliGeomHandles to be created on the stack and thus avoids a common source of memory leaks. The lookup procedure is so fast that users should not be concerned with (or even attempt) to retain a handle, but rather should construct one from a VldContext whenever one is needed.
#include "UgliGeometry/UgliGeomHandle.h" // retrieve a copy of the VldContext object identifying // the configuration of the current record VldContext vldc = [..] // create a UgliGeomxHandle (on the stack) UgliGeomHandle ugh(vldc) [....] // work with UgliGeomHandle and it gets automagically destroyed // when the code block ends, but the next invocation is // likely to acquire the same underlying UgliGeometry without // significant overhead.
// UgliLoanPool is a CfgConfigurable UgliLoanPool* ulpool = UgliLoanPool::Instance(); ulpool->Set("..."); ulpool->Set("..."); ulpool->Update();
On startup the interface checks the environmental variable
which can contain a semi-colon separated list of configuration requests,
setenv ENV_UGLI "MaxUnref=2; AlwaysUseDbi=0"One can also show the current status of the UgliLoanPool using:
UgliLoanPool::Instance()->Print();which gives something like:
"UgliLoanPool Configuration", 13 entries. keys unlocked, values unlocked AlgorithmicCalDet = 0 AlgorithmicFar = 0 AlgorithmicNear = 0 AlwaysUseDbi = 1 Cache = '' CacheWrite = 1 CutAppliesToMC = 0 CutAppliesToVetoShield = 0 CutMsgLevel = 'Synopsis' CutOnPlnInstallCalDet = 0 CutOnPlnInstallFar = 1 CutOnPlnInstallNear = 0 MaxUnref = 1 --- Frozen UgliLoanPool --- UgliGeometry has 1 references |CalDet|Data| 2001-07-24 00:00:04.000000000Z 2001-08-13 00:00:04.000000000Z from source: DBI, From Database fRootGeom "Frozen|CalDet|Data|2001-07-24 00:00:04" --- Modifiable UgliLoanPool --- --- End of UgliLoanPool ---
Nevertheless, it is sometime useful. This behavour can be enabled by setting the Cache config variable to the name of the root file to use. One then runs the job once to build the necessary geometry from the database and the job will write the file upon teardown of the UgliLoanPool at job end. Subsequent jobs will then read the cached file and can avoid the re-writing overhead by setting the CacheWrite config value to zero.
UgliGeomHandle cold_geom(vldc,Ugli::kFrozen); UgliGeomHandle playdough_geom(vldc,Ugli::kModifiable); UgliGeomHandle oneofthetwo_geom(vldc);
The cold_geom and playdough_geom are distinct geometries. The third geometry, since it has a compatible VldContext, is guarenteed to be one of the two previously created. But exactly which depends on the state of the DefaultModifyMode. This allows one to set the default so that an code written using the single argument for the constructor can be toggled:
Ugli::SetDefaultModifyMode(Ugli::kModifiable); // run a job path to do some tracking/fitting // it will run using the modified geometry // even if it wasn't explicitly written to do so. [...] // run a chi2 check against the modified geometry [...] Ugli::SetDefaultModifyMode(Ugli::kFrozen); // run a chi2 check against the frozen (Database) geometry [...]
Example code demonstrating some of the adjustment capabilities is show below:
UgliStripHandle ush = playdough_geom.GetStripHandle(stripid); UgliScintPlnHandle usph = ush.GetScintPlnHandle(); UgliScintMdlHandle usmh = ush.GetScintMdlHandle(); // shift,rotate the strip relative to the module by // some delta from current position // L=longitudinal position, T=transverse position //ush.ShiftLTPosRelMdlBy(0*Munits::cm,1.0*Munits::cm); //ush.RotateRelMdlBy(2.0*Munits::mrad); // shift,rotate module relative to scint plane by absolute amounts usmh.SetLTPosRelPln(1.5*Munits::cm,200.0*Munits::cm); usmh.SetZRotRelPlnRad(2.0*Munits::mrad); // see Ugli*Handle for more details about available methods // currently UgliSteelPlnHandle's can not be adjusted.