view misc.py @ 78:47da95b31dcb

Move sifmt function to where it can be reused.
author Daniel O'Connor <doconnor@gsoft.com.au>
date Fri, 27 Sep 2024 16:50:42 +0930
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children 4cc3d0706dd1
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#!/usr/bin/env python

# Copyright (c) 2024
#      Daniel O'Connor <darius@dons.net.au>.  All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

def sifmt(_v, dp = 3, unit = 'Hz', sp = ' '):
    '''Format a number using SI prefixes'''
    si_prefixes = ('T', 'G', 'M', 'k', '', 'm', 'ยต', 'n', 'p')
    scale = 10 ** 12
    v = abs(_v)
    if v == 0:
        sip = ""
        scale = 0
    for i, sip in enumerate(si_prefixes):
        if v >= scale:
            break
        scale /= 1e3
    return ('%.' + str(dp) + 'f%s%s%s') % (_v / scale, sp, si_prefixes[i], unit)