[R] Searching for antilog function

[Richard M. Heiberger]

Use power

> log(78,10)
[1] 1.892095
> 10^log(78,10)
[1] 78

On Tue, May 31, 2016 at 4:14 PM, Carlos <arnobras at hotmail.com> wrote:
> The following function can do the work as well
>
>  antilog<-function(lx,base)
>  {
>  lbx<-lx/log(exp(1),base=base)
>  result<-exp(lbx)
>  result
>  }
>
> This solution is based on the change of base formula which states that :
>
> log (x,base=b) = log(x,base=a)/log(b,base=a)
>
> The original logarithm is changed into natural logarithm and then the
> exponential function is employed
>
> The arguments are:
>
> 'lx', de logarithm we have.
> 'base', the base what was employed to obtain lx
>
> For example:
>
> log(78,10) = 1.892095
>
> Then the antllog is
>
> antilog(1.892095,10)
>
> 78
>
> As expected.
>
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