dollarFraction¶

Converts a decimal price to a fractional price.

Synopsis¶

dollarFraction (decimalDollar, fraction)

Required Arguments¶

float decimalDollar (Input): Dollar price expressed as a decimal number.
int fraction (Input): Denominator of the fractional dollar. fraction must be positive.

Return Value¶

The dollar price expressed as a fraction. The numerator is the decimal part of the return value. If no result can be computed, NaN is returned.

Description¶

Function dollarFraction converts a dollar price, expressed as a decimal number, into a dollar price, expressed as a fractional price. If no result can be computed, NaN is returned.

It can be found by solving the following

\[\mathit{idollar} + \frac {\left[\mathit{decimalDollar} - \mathit{idollar}\right]} {10^{(\mathrm{ifrac}+1)} / \mathit{fraction}}\]

where idollar is the integer part of the decimalDollar, and ifrac is the integer part of log(fraction).

Example¶

In this example, dollarFraction converts $1.25 to $1 1/4.

from __future__ import print_function
from numpy import *
from pyimsl.math.dollarFraction import dollarFraction

decimal_dollar = 1.25
fraction = 4
dollarfrc = dollarFraction(decimal_dollar, fraction)
numerator = dollarfrc * 10. - int(dollarfrc) * 10

print("The decimal dollar $1.25 as a fractional dollar = ", end=' ')
print("$%i %i/%i." % (int(dollarfrc), numerator, fraction))

Output¶

The decimal dollar $1.25 as a fractional dollar =  $1 1/4.