pressure

#!/usr/bin/env python3
#
# pressure: Show a given pressure in many units.
# 2015-10-28: Written by Steven J. DeRose.
#
import sys
import argparse

__metadata__ = {
    "title"        : "pressure",
    "description"  : "Show a given pressure in many units.",
    "rightsHolder" : "Steven J. DeRose",
    "creator"      : "http://viaf.org/viaf/50334488",
    "type"         : "http://purl.org/dc/dcmitype/Software",
    "language"     : "Python 3.7",
    "created"      : "2015-10-28",
    "modified"     : "2020-08-31",
    "publisher"    : "http://github.com/sderose",
    "license"      : "https://creativecommons.org/licenses/by-sa/3.0/"
}
__version__ = __metadata__['modified']

descr = """
=Description=

Given a pressure as a number and a unit name, display the equivalent pressure
in lots of other unitsOfPressure.

==Usage==

    pressure 2.0 atmStd

will produce:

You have: 2.000000 atmStd, which equals:
                0.202650 MPa
           202650.054766 Pa
                2.000000 atmStd
                2.066463 atmTech
                2.026501 bar
             2066.512360 cmH2O
              152.000005 cmHg
               67.797184 ftH2O
                4.986873 ftHg
             2066.463138 g/cm2
             2026.500548 hPa
              813.587713 inH2O
               59.842521 inHg
              202.650055 kPa
                2.066463 kg/cm2
             2026.500548 mbar
            20665.123599 mmH2O
             1520.000051 mmHg
          1520000.050663 mtorr
             4232.427454 psf
               29.391906 psi
             1520.000051 torr


=Related Commands=

The *nix ''unitsOfPressure'' command can do compound unitsOfPressure like:
    unitsOfPressure 9.8 m/s^2 feet/s^2
    unitsOfPressure 14 psi cm water


=References=

[http://www.sensorsone.com/kpa-kilopascal-pressure-unit]


=Known bugs and Limitations=

Should probably just learn more other unitsOfPressure; maybe just harvest C<unitsOfPressure>'s
F</usr/share/misc/unitsOfPressure.lib> list.

Contains table of flow rate units, should expose that.

With --format, you may need to double the leading "%".


=To do=

* Option to request a particular output unit(s).


=Licensing=

Copyright 2015 by Steven J. DeRose. This script is licensed under a
Creative Commons Attribution-Share-alike 3.0 unported license.
See http://creativecommons.org/licenses/by-sa/3.0/ for more information.


=History=

* Written 2010-04-01~23 by Steven J. DeRose (originally in Perl).
* 2020-04-08: New laout.
* 2020-05-01: Add --tableFrom.
* 2020-08-31: New layout.


=Rights=

Copyright 2015, Steven J. DeRose. This work is licensed under a Creative Commons
Attribution-Share Alike 3.0 Unported License. For further information on
this license, see [http://creativecommons.org/licenses/by-sa/3.0/].

For the most recent version, see [http://www.derose.net/steve/utilities] or
[http://github/com/sderose].


=Options=
"""

unitsOfPressure = {
    # 1.0 kPa is equal to:
    "kPa":		     1.000,
    "MPa":           0.001,
    "hPa":          10.000,
    "Pa":		  1000.000,

    "atmTech":	     0.0101972,
    "atmStd":        0.00986923,
    "bar":		     0.010,
    "mbar":		    10.000,

    "inHg":		     0.2952998,
    "ftHg":          0.0246083,
    "mmHg":		     7.50061505,
    "cmHg":		     0.750061505,

    "inH2O":		 4.01474213,
    "ftH2O":         0.334553,
    "mmH2O":	   101.97442889,
    "cmH2O":		10.197442889,

    "torr":          7.50061505,
    "mtorr":      7500.61505,

    "psi":		     0.14503774,
    "psf":          20.8854,

    "g/cm2":         10.1972,
    "kg/cm2":         0.0101972,
}
unitNames = sorted(unitsOfPressure.keys())

unitsOfFlow = {  # 1.0 lpm is equal to:
    "lpm":            1.0,
    "lps":            0.0167,
    "cfm":            0.0353,
    "cms":            1.67E-5,
    "gpm":            0.26417,
    "gph":            0.0044028,
}

def from_kPa(f, targetUnitName):
    return f * unitsOfPressure[targetUnitName]

def to_kPa(f, sourceUnitName):
    return f / unitsOfPressure[sourceUnitName]

def from_to(f, sourceUnitName, targetUnitName):
    m = multiplierForUnit1ToGetUnit2(sourceUnitName, targetUnitName)
    return f * m

def multiplierForUnit1ToGetUnit2(u1, u2):
    return unitsOfPressure[u2]/unitsOfPressure[u1]


###############################################################################
#
def processOptions():
    try:
        from BlockFormatter import BlockFormatter
        parser = argparse.ArgumentParser(
            description=descr, formatter_class=BlockFormatter)
    except ImportError:
        parser = argparse.ArgumentParser(description=descr)

    parser.add_argument(
        "--divide", action='store_true',
        help='With --tableFrom, show what to divide by, not multiply by.')
    parser.add_argument(
        "--format", type=str, default="%%16.6f",
        help='Use this format to output the numbers. Default: "%%16.6f"')
    parser.add_argument(
        "--quiet", "-q", action='store_true',
        help='Suppress most messages.')
    parser.add_argument(
        "--tableFrom", action='store_true',
        help='Generate a Python dict of multipliers to convert the unit.')
    parser.add_argument(
        "--to", "-t", type=str, choices=unitsOfPressure.keys(),
        help='Only report this target unit.')
    parser.add_argument(
        "--verbose", "-v", action='count', default=0,
        help='Add more messages (repeatable).')
    parser.add_argument(
        "--version", action='version', version=__version__,
        help='Display version information, then exit.')

    parser.add_argument(
        'p', type=float,
        help='pressure')
    parser.add_argument(
        'unit', type=str, choices=unitNames,
        help='pressure unit')

    args0 = parser.parse_args()
    return(args0)


###############################################################################
# Main
#
args = processOptions()


if (args.tableFrom):
    kw = "Divide" if (args.divide) else "Multiply"
    print("    # %s %s by these values to get to other units" %
        (kw, args.unit))
    print("    from_%s_to = {" % (args.unit))
    lineFormat = "        %-12s : " + args.format + ","
    for targetUnit in unitNames:
        mfactor = multiplierForUnit1ToGetUnit2(args.unit, targetUnit)
        if (args.divide):
            print(lineFormat % ('"'+targetUnit+'"', 1/mfactor))
        else:
            print(lineFormat % ('"'+targetUnit+'"', mfactor))
    print("    }")

else:
    print("You have: %f %s, which equals:" % (args.p, args.unit))
    kPa = to_kPa(args.p, args.unit)
    lineFormat = "        " + args.format + " %s"
    for u in unitNames:
        if (not args.to or args.to == u):
            print(lineFormat % (kPa*unitsOfPressure[u], u))

sys.exit()