[R] HELP asin transformation

[Marc Girondot]

Le 22/02/2015 19:28, CHIRIBOGA Xavier a écrit :
> Dear all,
>
>
>
> I attempted to transform my data using "asin" but a WARNING message appears:
>
>
>
> dat1$Abu.tr<-asin(sqrt(dat1$Abundance/100))
> Warning message:
> In asin(sqrt(dat1$Abundance/100)) : NaNs produced
>
>
>
> What does it mean? Is it a problem? How can I solve this?
>
>
>
One or more of your Abundance data is negative, higher than 100 or 
non-finite:

 > asin(seq(from=-2, to=2, by=0.1))
  [1]        NaN        NaN        NaN        NaN        NaN NaN        NaN
  [8]        NaN        NaN        NaN -1.5707963 -1.1197695 -0.9272952 
-0.7753975
[15] -0.6435011 -0.5235988 -0.4115168 -0.3046927 -0.2013579 -0.1001674  
0.0000000
[22]  0.1001674  0.2013579  0.3046927  0.4115168  0.5235988 0.6435011  
0.7753975
[29]  0.9272952  1.1197695  1.5707963        NaN        NaN NaN        NaN
[36]        NaN        NaN        NaN        NaN        NaN NaN
Message d'avis :
In asin(seq(from = -2, to = 2, by = 0.1)) : production de NaN
 > sqrt(seq(from=-2, to=2, by=0.1))
  [1]       NaN       NaN       NaN       NaN       NaN NaN       
NaN       NaN
  [9]       NaN       NaN       NaN       NaN       NaN NaN       
NaN       NaN
[17]       NaN       NaN       NaN       NaN 0.0000000 0.3162278 
0.4472136 0.5477226
[25] 0.6324555 0.7071068 0.7745967 0.8366600 0.8944272 0.9486833 
1.0000000 1.0488088
[33] 1.0954451 1.1401754 1.1832160 1.2247449 1.2649111 1.3038405 
1.3416408 1.3784049
[41] 1.4142136
Message d'avis :
In sqrt(seq(from = -2, to = 2, by = 0.1)) : production de NaN

But take a look at this also about arcsine transformation:
Warton, D.I., Hui, F.K.C., 2011. The arcsine is asinine: the analysis of 
proportions in ecology. Ecology 92, 3-10.

Sincerely,

Marc