Re: unwrap modulo 2pi

[Randall Skelton <rhskelto(at)atm.ox.ac.uk>]

Modulo Operator Notes

quotient:   q = a / b
remainder:  r = a mod b

So,

 a     b    a/b     a mod b
 10    3     3      1
  3   10     0      3
-10   -3    -3     -1

It is *always* true that a = q*b + r with abs(r) < abs(b) and b neq 0

Randall

graham_wilson@my-deja.com wrote:
> My appologies for not being explicit enough...
>  
> IDL> a=[2,4,6,8,10,12]
> IDL> a=[2.,4.,6.,8.,10.,12.]
> IDL> b=2*!PI
> IDL> c=a mod b
> IDL> print, c
>       2.00000  4.00000   6.00000   1.71681  3.71681   5.71681
>  
> What I mean by 'unwraping' is: Given I know 'c' and 'b' how do I
> explicitly find a?
>