Using findInterval after discretization in R

Question

After discretizing a variable (interval method), I'm having trouble checking if a value belongs to an interval.

Discretizing c(1:10) in a vector a:

(a<-unique(discretize(1:10,method="interval",5)))

[1] [ 1.0, 2.8) [ 2.8, 4.6) [ 4.6, 6.4) [ 6.4, 8.2) [ 8.2,10.0]

and then checking in which interval the value 4 is in yelds:

for(i in 1:5){print(findInterval(x=4,a[i]))}

[1] 1

[1] 1

[1] 1

[1] 1

[1] 0

while it should result in 0 1 0 0 0

What am I doing wrong? the discretize function and findInterval don't work well together?

EDIT: Another related question: why after discretizing a column I get repeated values when I souldnt?, i.e.,

(a<-discretize(1:10,method="interval",5)) [1] [ 1.0, 2.8) [ 1.0, 2.8) [ 2.8, 4.6) [ 2.8, 4.6) [ 4.6, 6.4) [ 4.6, 6.4) [ 6.4, 8.2) [8] [ 6.4, 8.2) [ 8.2,10.0] [ 8.2,10.0]

Answer 1

I think you're using findInterval incorrectly. Your vector, a, doesn't need to be in that form. You only need a vector of the threshold points defining the intervals. try this

a<-seq(1,10, length.out=6)
findInterval(4,a)