Documentation: subset examples for pData

[wyoibc]

It is not clear how to subset the ballgown instance based on phenotypic data. The examples in subset documentation do not provide a clear example. Let's say the data consists of 18 samples as follows:

pheno

      sample lifestage cond
1  samp01     adult  con
2  samp02     adult  con
3  samp03     adult  con
4  samp04     adult  trt
5  samp05     adult  trt
6  samp06     adult  trt
7  samp07       old  con
8  samp08       old  con
9  samp09       old  con
10 samp10       old  trt
11 samp11       old  trt
12 samp12       old  trt
13 samp13       ped  con
14 samp14       ped  con
15 samp15       ped  con
16 samp16       ped  trt
17 samp17       ped  trt
18 samp18       ped  trt

I want to do a pairwise comparison between adult control and adult treatment. But I can't figure out how to subset the data.

adult <- subset(bg, 'lifestage == "adult"', genomesubset=FALSE)

subset must be logical