35 lines
927 B
C
35 lines
927 B
C
/*! \file kahansum.h
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* \brief Inline functions providing Kahan summation.
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*/
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#ifndef KAHANSUM_H
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#define KAHANSUM_H
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#include <complex.h>
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static inline void kahaninit(double * const sum, double * const compensation) {
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*sum = 0;
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*compensation = 0;
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}
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static inline void kahanadd(double *sum, double *compensation, double input) {
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double compensated_input = input - *compensation;
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double nsum = *sum + compensated_input;
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*compensation = (nsum - *sum) - compensated_input;
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*sum = nsum;
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}
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static inline void ckahaninit(complex double * const sum, complex double * const compensation) {
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*sum = 0;
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*compensation = 0;
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}
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static inline void ckahanadd(complex double *sum, complex double *compensation, complex double input) {
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complex double compensated_input = input - *compensation;
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complex double nsum = *sum + compensated_input;
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*compensation = (nsum - *sum) - compensated_input;
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*sum = nsum;
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}
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#endif //KAHANSUM_H
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