[R] question for if else

[Aimin Yan]

I have a data set like this
I want to assign "outward" to Y if sc <90 and assign "inward" to Y if sc>=90.
then cbind(p1982,Y) to get like these

p aa as ms cur sc Y
1 154l_aa ARG 152.04 108.83 -0.1020140  92.10410   inward
2 154l_aa THR  15.86  28.32  0.2563560 103.67100    inward
3 154l_aa ASP  65.13  59.16  0.0312137   7.27311     outward
4 154l_aa CYS  57.20  49.85 -0.0549589  72.97930    outward
5 154l_aa TYR  28.87  31.75  0.0526457  96.11660     inward
6 154l_aa ASN  31.14  31.09  0.0632711  55.65980    outward

does anyone know how to these?

Aimin

 > head(p1982)
         p  aa     as     ms        cur        sc
1 154l_aa ARG 152.04 108.83 -0.1020140  92.10410
2 154l_aa THR  15.86  28.32  0.2563560 103.67100
3 154l_aa ASP  65.13  59.16  0.0312137   7.27311
4 154l_aa CYS  57.20  49.85 -0.0549589  72.97930
5 154l_aa TYR  28.87  31.75  0.0526457  96.11660
6 154l_aa ASN  31.14  31.09  0.0632711  55.65980