Difference between revisions of "Erin's equation"
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Giantsquid (talk | contribs) |
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==Python sourcecode== | ==Python sourcecode== | ||
| + | <syntaxhighlight lang="Python" line='line'> | ||
def erin(x): | def erin(x): | ||
from math import * | from math import * | ||
t = pow(10, floor(log10(x))) | t = pow(10, floor(log10(x))) | ||
return t * floor(x/t) | return t * floor(x/t) | ||
| + | </syntaxhighlight> | ||
==Fortran sourcecode== | ==Fortran sourcecode== | ||
| − | function erin(x) result(m) | + | <syntaxhighlight lang="Fortran" line='line'> |
| − | use iso_fortran_env | + | pure function erin(x) result(m) |
| + | use iso_fortran_env, only: wp => real64 | ||
implicit none | implicit none | ||
| − | real( | + | real(wp),intent(in) :: x |
| − | real( | + | real(wp) :: m,t |
t = 10**floor(log10(x)) | t = 10**floor(log10(x)) | ||
m = t * floor(x/t) | m = t * floor(x/t) | ||
end function erin | end function erin | ||
| + | </syntaxhighlight> | ||
==Example== | ==Example== | ||
Latest revision as of 19:41, 9 August 2019
Erin's equation is a mathematical function which computes the number that is the same order of magnitude as a given number, but with only one significant digit.
Python sourcecode
1 def erin(x):
2 from math import *
3 t = pow(10, floor(log10(x)))
4 return t * floor(x/t)
Fortran sourcecode
1 pure function erin(x) result(m)
2 use iso_fortran_env, only: wp => real64
3 implicit none
4 real(wp),intent(in) :: x
5 real(wp) :: m,t
6 t = 10**floor(log10(x))
7 m = t * floor(x/t)
8 end function erin
Example
erin(9876.54321) = 9000.0
