Base class for calculating weight from spline. More...

#include <Splines/SplineBase.h>

Inheritance diagram for SplineBase:

Collaboration diagram for SplineBase:

Public Member Functions
	SplineBase ()
	Constructor.

virtual	~SplineBase ()
	Destructor.

virtual void	Evaluate ()=0
	CW: This Eval should be used when using two separate x,{y,a,b,c,d} arrays to store the weights; probably the best one here! Same thing but pass parameter spline segments instead of variations.

virtual std::string	GetName () const
	Get class name.

short int	GetNParams () const
	Get number of spline parameters.

Protected Member Functions
void	FindSplineSegment ()
	CW:Code used in step by step reweighting, Find Spline Segment for each param.

virtual void	CalcSplineWeights ()=0
	CPU based code which eval weight for each spline.

virtual void	ModifyWeights ()=0
	Calc total event weight.

void	getTF1Coeff (TF1_red &spl, int &nPoints, float &coeffs)
	CW: Gets the polynomial coefficients for TF1.

Protected Attributes
std::vector< FastSplineInfo >	SplineInfoArray

short int *	SplineSegments

float *	ParamValues
	Store parameter values they are not in FastSplineInfo as in case of GPU we need to copy paste it to GPU.

short int	nParams
	Number of parameters that have splines.

Detailed Description

Base class for calculating weight from spline.

Definition at line 25 of file SplineBase.h.

Constructor & Destructor Documentation

◆ SplineBase()

SplineBase::SplineBase ( )

Constructor.

Definition at line 7 of file SplineBase.cpp.

                       {
// *****************************************
  nParams = 0;
  SplineSegments = nullptr;
  ParamValues = nullptr;
}

◆ ~SplineBase()

SplineBase::~SplineBase ( )

virtual

Destructor.

Definition at line 16 of file SplineBase.cpp.

                        {
// *****************************************
}

Member Function Documentation

◆ CalcSplineWeights()

virtual void SplineBase::CalcSplineWeights ( )

protectedpure virtual

CPU based code which eval weight for each spline.

Implemented in PySplineBase, BinnedSplineHandler, and SMonolith.

◆ Evaluate()

virtual void SplineBase::Evaluate ( )

pure virtual

CW: This Eval should be used when using two separate x,{y,a,b,c,d} arrays to store the weights; probably the best one here! Same thing but pass parameter spline segments instead of variations.

Implemented in BinnedSplineHandler, PySplineBase, and SMonolith.

◆ FindSplineSegment()

void SplineBase::FindSplineSegment ( )

protected

CW:Code used in step by step reweighting, Find Spline Segment for each param.

Definition at line 24 of file SplineBase.cpp.

                                   {
// *************************
  // Loop over the splines
  //KS: Tried multithreading here with 48 splines and it is faster with one thread, maybe in future multithreading will be worth revisiting
  for (M3::int_t i = 0; i < nParams; ++i)
  {
    const M3::int_t nPoints = SplineInfoArray[i].nPts;
    const std::vector<M3::float_t>& xArray = SplineInfoArray[i].xPts;
 
    // Get the variation for this reconfigure for the ith parameter
    const float xvar = float(*SplineInfoArray[i].splineParsPointer);
    ParamValues[i] = xvar;
 
    // EM: if we have a parameter that has no response for any event (i.e. all splines have just one knot), then skip it and avoid a seg fault here
    //     In principle, such parameters shouldn't really be included in the first place, but with new det syst splines this
    //     could happen if say you were just running on one FHC run, then all RHC parameters would be flat and the code below would break.
    if(xArray.size() == 0) continue;
 
    // The segment we're interested in (klow in ROOT code)
    M3::int_t segment = 0;
    M3::int_t kHigh = nPoints-1;
    //KS: We expect new segment is very close to previous
    const M3::int_t PreviousSegment = SplineInfoArray[i].CurrSegment;
 
    // If the variation is below the lowest saved spline point
    if (xvar <= xArray[0]) {
      segment = 0;
      // If the variation is above the highest saved spline point
    } else if (xvar >= xArray[nPoints-1]) {
      //CW: Yes, the -2 is indeed correct, see TSpline.cxx:814 and //see: https://savannah.cern.ch/bugs/?71651
      segment = kHigh;
      //KS: It is quite probable the new segment is same as in previous step so try to avoid binary search, first we have to check if it is in bounds to avoid seg fault
    } else if( xArray[PreviousSegment+1] > xvar && xvar >= xArray[PreviousSegment] ) {
      segment = PreviousSegment;
      // If the variation is between the maximum and minimum, perform a binary search
    } else {
      // The top point we've got
      M3::int_t kHalf = 0;
      // While there is still a difference in the points (we haven't yet found the segment)
      // This is a binary search, incrementing segment and decrementing kHalf until we've found the segment
      while (kHigh - segment > 1) {
        // Increment the half-step
        kHalf = M3::int_t((segment + kHigh)/2);
        // If our variation is above the kHalf, set the segment to kHalf
        if (xvar > xArray[kHalf]) {
          segment = kHalf;
          // Else move kHigh down
        } else {
          kHigh = kHalf;
        }
      } // End the while: we've now done our binary search
    } // End the else: we've now found our point
 
    if (segment >= nPoints-1 && nPoints > 1) segment = nPoints-2;
 
    //CW: This way we avoid doing 1.2M+ binary searches on the GPU
    // and literally just multiply lots of numbers together on the GPU without any algorithm
    // Update the values and which segment it belongs to
    SplineInfoArray[i].CurrSegment = segment;
    SplineSegments[i] = short(SplineInfoArray[i].CurrSegment);
 
    #ifdef DEBUG
    if (SplineInfoArray[i].xPts[segment] > xvar && segment != 0) {
      MACH3LOG_ERROR("Found a segment which is _ABOVE_ the variation!");
      MACH3LOG_ERROR("IT SHOULD ALWAYS BE BELOW! (except when segment 0)");
      MACH3LOG_ERROR("Spline: {}", i);
      MACH3LOG_ERROR("Found segment = {}", segment);
      MACH3LOG_ERROR("Doing variation = {}", xvar);
      MACH3LOG_ERROR("x in spline = {}", SplineInfoArray[i].xPts[segment]);
      for (M3::int_t j = 0; j < SplineInfoArray[j].nPts; ++j) {
        MACH3LOG_ERROR("    {} = {}", j, SplineInfoArray[i].xPts[j]);
      }
      throw MaCh3Exception(__FILE__ , __LINE__ );
    }
    #endif
  } //end loop over params
}

◆ GetName()

virtual std::string SplineBase::GetName ( ) const

inlinevirtual

Get class name.

Reimplemented in SMonolith, and PySplineBase.

Definition at line 36 of file SplineBase.h.

36{return "SplineBase";};

◆ GetNParams()

short int SplineBase::GetNParams ( ) const

inline

Get number of spline parameters.

Definition at line 39 of file SplineBase.h.

39{return nParams;};

◆ getTF1Coeff()

void SplineBase::getTF1Coeff	(	TF1_red *&	spl,
		int &	nPoints,
		float *&	coeffs
	)

protected

CW: Gets the polynomial coefficients for TF1.

Parameters

spl	pointer to TF1_red that will be checked
nPoints	number of knots
coeffs	Array holding coefficients for each knot

Definition at line 106 of file SplineBase.cpp.

                                                                         {
// *****************************************
  // Initialise all arrays to 1.0
  for (int i = 0; i < _nTF1Coeff_; ++i) {
    coeffs[i] = 0.0;
  }
 
  // Get number of points in spline
  nPoints = spl->GetSize();
 
  if(nPoints > _nTF1Coeff_)
  {
    MACH3LOG_ERROR("Too big number of points for TF1");
    throw MaCh3Exception(__FILE__ , __LINE__ );
  }
  // TSpline3 can only take doubles, not floats
  // But our GPU is slow with doubles, so need to cast to float
  for (int i = 0; i < nPoints; i++) {
    coeffs[i] = float(spl->GetParameter(M3::int_t(i)));
  }
  // The structure is now coeffs  = {a,b,c,d,e}
}

◆ ModifyWeights()

virtual void SplineBase::ModifyWeights ( )

protectedpure virtual

Calc total event weight.

Implemented in PySplineBase, BinnedSplineHandler, and SMonolith.

Member Data Documentation

◆ nParams

short int SplineBase::nParams

protected

Number of parameters that have splines.

Definition at line 64 of file SplineBase.h.

◆ ParamValues

float* SplineBase::ParamValues

protected

Store parameter values they are not in FastSplineInfo as in case of GPU we need to copy paste it to GPU.

Definition at line 62 of file SplineBase.h.

◆ SplineInfoArray

std::vector<FastSplineInfo> SplineBase::SplineInfoArray

protected

Array of FastSplineInfo structs: keeps information on each xsec spline for fast evaluation Method identical to TSpline3::Eval(double) but faster because less operations

Definition at line 57 of file SplineBase.h.

◆ SplineSegments

short int* SplineBase::SplineSegments

protected

Store currently found segment they are not in FastSplineInfo as in case of GPU we need to copy paste it to GPU

Warning: this is being used sometimes by GPU, therefore must be raw pointer!

Definition at line 60 of file SplineBase.h.

The documentation for this class was generated from the following files:

Splines/SplineBase.h
Splines/SplineBase.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SplineBase()

◆ ~SplineBase()

Member Function Documentation

◆ CalcSplineWeights()

◆ Evaluate()

◆ FindSplineSegment()

◆ GetName()

◆ GetNParams()

◆ getTF1Coeff()

◆ ModifyWeights()

Member Data Documentation

◆ nParams

◆ ParamValues

◆ SplineInfoArray

◆ SplineSegments