[R] Conditions in R (Help Post)

[Jim Lemon]

Hi Yeasmin,
I suspect that you didn't intend to have conditions like:

a<0 && b>0 && b<a)

I'm going to guess that you meant:

a < 0 && b > 0 && abs(b) < abs(a)

If this is the case, the following function seems to return the values
of phase that you want:

assign_phase<-function(x,y) {
 phase<-c(1,2,7,8,3,4,6,5)
 phase_index<-4 * (x > 0) + 2 * (y > 0) + (abs(x) < abs(y))
 return(phase[phase_index+1])
}

Jim

On Wed, Oct 23, 2019 at 3:43 AM Yeasmin Alea <yeasmin.alea using gmail.com> wrote:
>
> Hello Team
> I would like to add a new column (for example-Phase) from the below data
> set based on the conditions
>    YEAR   DAY      X     Y   Sig
>  1  1981     9 -0.213 1.08   1.10
>  2  1981    10  0.065 1.05   1.05
> *Conditions*
>
> D$Phase=sapply(D,function(a,b) {
>      a <-D$X
>      b<-D$Y
>      if (a<0 && b<0 && b<a)
>     {phase=1} else if (a<0 && b<0 && b>a)
>     {phase=2} else if (a<0 && b>0 && b<a)
>     {phase=7} else if (a<0 && b>0 && b>a)
>     {phase=8} else if (a>0 && b<0 && b<a)
>     {phase=3} else if (a>0 && b<0 && b>a)
>     {phase=4} else if (a>0 && b>0 && b>a)
>     {phase=6} else (a>0 && b>0 && b<a)
>     {phase=5}
> })
>
> Can anyone help to fix the script to get a Phase column based on the
> conditions. The table will be like the below
>    YEAR   DAY      X     Y   Sig      Phase
>  1  1981     9 -0.213 1.08   1.10   phase=7
>  2  1981    10  0.065 1.05   1.05   phase=6
>
> Many thanks
> Alea
>
>         [[alternative HTML version deleted]]
>
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