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This commit is contained in:
Gabriele Cosmo
2016-06-08 15:09:25 +02:00
parent b97f8d0df7
commit aaa409b6ee
2922 changed files with 55107 additions and 81674 deletions
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source/geometry/magneticfield/src/G4MagIntegratorDriver.cc
+89 -15
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@@ -5,8 +5,8 @@
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4MagIntegratorDriver.cc,v 2.4 1998/11/11 18:51:48 japost Exp $
// GEANT4 tag $Name: geant4-00 $
// $Id: G4MagIntegratorDriver.cc,v 1.4 1999/07/06 20:22:34 japost Exp $
// GEANT4 tag $Name: geant4-00-01 $
//
//
//
@@ -23,6 +23,8 @@
#include "G4MagIntegratorDriver.hh"
#include "G4FieldTrack.hh"
// #define G4DEBUG 1
// Stepsize can increase by no more than 5.0
// and decrease by no more than 1/10. = 0.1
//
@@ -51,7 +53,8 @@ G4MagInt_Driver::AccurateAdvance(
{
static const G4int maxstp = 5000;
G4int nstp, i ;
G4int nstp, i;
static G4int dbg=1;
G4double x, hnext, hdid, h ;
// G4double yscal[ncompSVEC];
@@ -73,29 +76,79 @@ G4MagInt_Driver::AccurateAdvance(
h = hstep;
x = x1;
G4int nOK =0, nBAD = 0 ;
G4int noFullIntegr=0, noSmallIntegr = 0 ;
static G4int noGoodSteps =0, noBadSteps = 0 ; // Bad = chord > curve-len
for(i=0;i<nvar;i++) y[i] = ystart[i] ;
nstp=1;
do{
#ifdef G4DEBUG
G4ThreeVector StartPos( y[0], y[1], y[2] );
#endif
pIntStepper->RightHandSide( y, dydx );
if( x+h > x2 ) h = x2 - x ; // When stepsize overshoots, decrease it!
OneGoodStep(y,dydx,x,h,eps,hdid,hnext) ;
if(hdid == h) nOK++ ; else nBAD++ ;
#ifdef G4DEBUG
if(hdid == h) noFullIntegr++ ; else noSmallIntegr++ ;
G4ThreeVector EndPos( y[0], y[1], y[2] );
G4double endPointDist= (EndPos-StartPos).mag();
if( endPointDist >= h*(1.+perMillion) ){
static G4double maxRelError= 0.0;
G4bool isNewMax;
noBadSteps ++;
isNewMax = endPointDist > (1.0 + maxRelError) * h;
if( isNewMax )
maxRelError= endPointDist / h - 1.0;
if( dbg && ( isNewMax || (endPointDist >= h*(1.+eps) ) ) ){
static G4int noWarnings = 0;
if( (noWarnings ++ < 10) || (dbg>1) ){
G4cerr << " Warning (G4MagIntergratorDriver): "
<< " The integration produced an endpoint which " << endl
<< " is further from the startpoint than the curve length." << endl;
G4cerr << " Distance of endpoints = " << endPointDist
<< " curve length = " << h
<< " Difference (curveLen-endpDist)= " << (h - endPointDist)
<< " relative = " << (h-endPointDist) / h
<< endl;
}else{
G4cerr << " EndpointDist = " << endPointDist
<< " curve length = " << h
<< " Diff (cl-ed)= " << (h - endPointDist)
<< " rel = " << (h-endPointDist) / h
<< endl;
}
} else { // ie (!dbg)
noGoodSteps ++;
} // end if (dbg)
}
#endif
if(fabs(hnext) <= Hmin())
{
succeeded = false;
// If simply a very small interval is being integrated, ...
if( (fabs(hstep) > Hmin()) || (hnext > h) ){
// If simply a very small interval is being integrated, do not warn
if( (x < x2 * (1-eps) ) && // The last step can be small: it's OK
(fabs(hstep) > Hmin()) // and if we are asked, it's OK
// && (hnext < hstep * PerThousand )
)
{
G4cerr<< " Warning (G4MagIntergratorDriver): The stepsize for the "
" next iteration=" << hnext << " is too small - in Step number "
<<nstp << " . Minimum for driver = "<< Hmin() << endl ;
<<nstp << "." << endl;
G4cerr << " Requested step size was " << hstep << " ." << endl ;
G4cerr << " Previous step size was " << h << " ." << endl ;
G4cerr << " The minimum for the driver is " << Hmin() << endl ;
}
// else succeeded = false; // Not meaningful unless it is used to
// break out of the loop.
}
h = hnext ;
@@ -150,23 +203,35 @@ G4MagInt_Driver::OneGoodStep( G4double y[],
// 16.2 Adaptive StepSize Control for Runge-Kutta, p. 719
{
G4double errpos_sq, errvel_sq, errmax_sq;
G4double errmax, h, htemp, xnew ;
G4int i;
const G4double eps_vel_rel= eps; // The same relative error
// (eps too is a pure number)
G4double yerr[G4FieldTrack::ncompSVEC], ytemp[G4FieldTrack::ncompSVEC];
h = htry ; // Set stepsize to the initial trial value
// G4double inv_epspos_sq= 1.0 / eps * eps;
for (;;)
{
pIntStepper-> Stepper(y,dydx,h,ytemp,yerr) ;
pIntStepper-> Stepper(y,dydx,h,ytemp,yerr);
G4double eps_pos = eps * h;
// Evaluate accuracy
//
errmax = sqrt( sqr(yerr[0]) + sqr(yerr[1]) + sqr(yerr[2]) );
errpos_sq = sqr(yerr[0]) + sqr(yerr[1]) + sqr(yerr[2]) ;
errpos_sq /= eps_pos*eps_pos; // Scale relative to required tolerance
errmax /= eps; // Scale relative to required tolerance
if(errmax <= 1.0 ) break ; // Step succeeded.
// Accuracy for velocity
errvel_sq = (sqr(yerr[3]) + sqr(yerr[4]) + sqr(yerr[5]) )
/ (sqr(y[3]) + sqr(y[4]) + sqr(y[5]) );
errvel_sq /= eps_vel_rel*eps_vel_rel;
errmax_sq = max( errpos_sq, errvel_sq ); // Square of maximum error
errmax = sqrt( errmax_sq );
if(errmax_sq <= 1.0 ) break ; // Step succeeded.
// Step failed; compute the size of retrial Step.
htemp = GetSafety()*h*pow(errmax,GetPshrnk()) ;
@@ -205,10 +270,11 @@ G4bool G4MagInt_Driver::QuickAdvance(
const G4double dydx[],
G4double hstep, // In
G4double& dchord_step,
G4double& dyerr_len )
G4double& dyerr )
{
G4double yerr_vec[G4FieldTrack::ncompSVEC], yarrin[G4FieldTrack::ncompSVEC], yarrout[G4FieldTrack::ncompSVEC];
G4double s_start;
G4double dyerr_len, dyerr_vel, vel_mag;
// Move data into array
y_posvel.DumpToArray( yarrin ); // yarrin <== y_posvel
@@ -227,7 +293,15 @@ G4bool G4MagInt_Driver::QuickAdvance(
// A single measure of the error
// TO-DO : account for tangent vector, energy, spin, ... ?
dyerr_len= sqrt( sqr(yerr_vec[0])+sqr(yerr_vec[1])+sqr(yerr_vec[2]));
dyerr_vel= sqrt( sqr(yerr_vec[3])+sqr(yerr_vec[4])+sqr(yerr_vec[5]));
vel_mag = sqrt( sqr(yarrout[3])+sqr(yarrout[4])+sqr(yarrout[5]) );
if( (dyerr_len / hstep) > (dyerr_vel / vel_mag) ) {
dyerr = dyerr_len;
}else{
// Scale it to the position - for now
dyerr = (dyerr_vel / vel_mag) * hstep;
}
#ifdef RETURN_A_NEW_STEP_LENGTH
// The following step cannot be done here because "eps" is not known.
dyerr_len /= eps;