[R] Comparing complex numbers
David Stoffer
dsstoffer at gmail.com
Fri Jul 11 17:51:28 CEST 2008
Is there an easy way to compare complex numbers?
Here is a small example:
> (z1=polyroot(c(1,-.4,-.45)))
[1] 1.111111-0i -2.000000+0i
> (z2=polyroot(c(1,1,.25)))
[1] -2+0i -2+0i
> x=0
> if(any(identical(z1,z2))) x=99
> x
[1] 0
# real and imaginary parts:
> Re(z1); Im(z1)
[1] 1.111111 -2.000000
[1] -8.4968e-21 8.4968e-21
> Re(z2); Im(z2)
[1] -2 -2
[1] 0 0
Both z1 and z2 have a root of -2, but I guess Im(z1)
isn't close enough to zero for identical().
TIA.
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The power of accurate observation is commonly called cynicism
by those who have not got it. George Bernard Shaw
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