Difference between revisions of "Erin's equation"

From Bacliff Exploration Society
Jump to navigation Jump to search
Line 3: Line 3:
 
==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==

Revision as of 19:40, 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

pure function erin(x) result(m)
 use iso_fortran_env, only: wp => real64
 implicit none
 real(wp),intent(in) :: x
 real(wp) :: m,t
 t = 10**floor(log10(x))
 m = t * floor(x/t)
end function erin

Example

erin(9876.54321) = 9000.0

See also