cms.fundamental.sum_error のソースコード

import sys
import csv
import numpy as np

outfile = 'sum_error.csv'
h = 0.01
n = 101
iprintstep = 10




def getintarg(argv, iarg, defval=None):
    try:
        return int(argv[iarg])
    except Exception:
        return defval





def getfloatarg(argv, iarg, defval=None):
    try:
        return float(argv[iarg])
    except Exception:
        return defval





def main():
    global h, n, iprintstep

    argv = sys.argv
    narg = len(argv)

    if narg <= 2:
        print("")
        print("Usage: python sum_error.py h n iPrintStep")
        print("    Summing up h for n times with different precision floating point types.")
        print("    Output every iPrintStep steps")
        print("")
        return

    h = getfloatarg(argv, 1, h)
    n = getintarg(argv, 2, n)
    iprintstep = getintarg(argv, 3, iprintstep)

    h16 = np.array([h], dtype=np.float16)
    sum16 = np.array([0.0], dtype=np.float16)

    h32 = np.array([h], dtype=np.float32)
    sum32 = np.array([0.0], dtype=np.float32)

    h64 = np.array([h], dtype=np.float64)
    sum64 = np.array([0.0], dtype=np.float64)

    ex = np.array([0.0], dtype=np.float64)
    err16 = np.array([0.0], dtype=np.float64)
    err32 = np.array([0.0], dtype=np.float64)
    err64 = np.array([0.0], dtype=np.float64)

    print("")
    print(
        "Summing up {} for {} times with "
        "different precision floating point types".format(h, n)
    )
    print("Write to [{}]".format(outfile))

    with open(outfile, 'w', newline='') as f:
        fout = csv.writer(f, lineterminator='\n')
        fout.writerow([
            'exact', 'float16', 'float32', 'float64',
            'error(float16)', 'error(float32)', 'error(float64)'
        ])

        print("")
        print(f"{'exact':^5}:\t{'sum16 (error)':^28}\t{'sum32 (error)':^28}\t{'sum64 (error)':^28}")

        for i in range(n):
            ex[0] = (i + 1) * h

            sum16[0] += h16[0]
            err16[0] = ex[0] - sum16[0]

            sum32[0] += h32[0]
            err32[0] = ex[0] - sum32[0]

            sum64[0] += h64[0]
            err64[0] = ex[0] - sum64[0]

            fout.writerow([
                ex[0], sum16[0], sum32[0], sum64[0],
                err16[0], err32[0], err64[0]
            ])

            if i % iprintstep == 0:
                print(f"{ex[0]:<0.4f}: ", end='')
                print(f"{sum16[0]:<0.18f} ({err16[0]:<+9.2e})  ", end='')
                print(f"{sum32[0]:<0.18f} ({err32[0]:<+9.2e})  ", end='')
                print(f"{sum64[0]:<0.18f} ({err64[0]:<+9.2e})  ", end='')
                print("")

    print("")



if __name__ == "__main__":
    main()