eschnett/cactusamrex - Change 7HYSOSJWVEE7ZA5SDYVD6KFNQL7AWNZYNDYGTXMM5DRDUAL65KUAC

CarpetX: Improve accuracy of standard deviation reduction

Created by Erik Schnetter on June 27, 2020

7HYSOSJWVEE7ZA5SDYVD6KFNQL7AWNZYNDYGTXMM5DRDUAL65KUAC

Dependencies

[2] WUOXLOK3CHUS2F3IEE6IOPUJBXLWJU4AHGJP44PMM2NED2ALVKZQC
[3] IBJK5HBMWKXUMHT7E2W5OVCA7SJYFRAHMJFP5K5CHWDQXBLEBC2QC
[4] VAF66DTVLDWNG7N2PEQYEH4OH5SPSMFBXKPR2PU67IIM6CVPCJ7AC

In channels

main

Change contents

Replacement in CarpetX/src/reduction.hxx at line 63 [4.2777]

B:BD[3.519] → [2.170:231]

    return sqrt(fmax1(T(0), sum2 / vol - pow21(sum / vol)));

[3.519]

[3.574]

    // Splitting pow21(sum/vol) improves floating-point accuracy
    // return sqrt(fmax1(T(0), sum2 / vol - pow21(sum / vol)));
    return sqrt(fmax1(T(0), sum2 / vol - pow21(sum) / pow21(vol)));