Try this
apply(data, 2, function(x) sum(is.na(x)))
lapply(data, function(x) sum(is.na(x)))
sapply(data, function(x) sum(is.na(x)))
Вопрос
I would like to apply a "composed" function on all columns of a data frame.
For the example, sum(is.na). But:
lapply(data, sum(is.na))
returns an error.
Of course, one "simple" function does work, such as
lapply(data, is.na)
So, how can we apply "functions of functions"?
In particular, the composed function I have in mind is
plot(table)
with as many graphics generated as there are columns in the data frame.
Решение
Try this
apply(data, 2, function(x) sum(is.na(x)))
lapply(data, function(x) sum(is.na(x)))
sapply(data, function(x) sum(is.na(x)))