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40 lines
1016 B
C++
40 lines
1016 B
C++
#ifndef GRID_MATH_EXP_H
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#define GRID_MATH_EXP_H
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#define DEFAULT_MAT_EXP 12
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namespace Grid {
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///////////////////////////////////////////////
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// Exponentiate function for scalar, vector, matrix
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///////////////////////////////////////////////
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template<class vtype> inline iScalar<vtype> Exponentiate(const iScalar<vtype>&r, ComplexD alpha , Integer Nexp = DEFAULT_MAT_EXP)
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{
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iScalar<vtype> ret;
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ret._internal = Exponentiate(r._internal, alpha, Nexp);
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return ret;
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}
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template<class vtype,int N, typename std::enable_if< GridTypeMapper<vtype>::TensorLevel == 0 >::type * =nullptr>
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inline iMatrix<vtype,N> Exponentiate(const iMatrix<vtype,N> &arg, ComplexD alpha , Integer Nexp = DEFAULT_MAT_EXP )
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{
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iMatrix<vtype,N> unit(1.0);
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iMatrix<vtype,N> temp(unit);
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for(int i=Nexp; i>=1;--i){
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temp *= alpha/ComplexD(i);
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temp = unit + temp*arg;
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}
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return ProjectOnGroup(temp);//maybe not strictly necessary
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}
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}
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#endif
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