Displaying 1 result from an estimated 1 matches for "meanbygroup".
2009 Mar 25
2
"with" and "by" and NA:
...variables for which I am performing the
mean by subgroup, for a pair of variables at a time, where one of them
for each pair defines the subgroup. The subgroups in the x$cm1 are 0, 1
and 2.
x
ph1 cm1
0.2345 2
1.2222 1
2.0033 0
0.0000 2
1.0033 1
0.2345 0
1.2222 2
2.0033 0
0.0000 1
1.0033 2
> meanbygroup <- as.vector(with(x, by(x$ph1, x$cm1, mean)))
> meanbygroup
if the ph1 has no missing values the above statements work fine:
[1] 1.4137000 0.7418333 0.6150000
In the moment that I introduce in the ph1 a missing value in the ph1 as NA
x
ph1 cm1
0.2345 2
NA 1
1.2222 1
.............
the...