I can't get seq to behave how I think it should

lut = seq(1.4, 2.1, by=0.001)
findInterval(1.8, lut)

On Jan 17, 2019, at 8:33 AM, POLWART, Calum (COUNTY DURHAM AND DARLINGTON NHS FOUNDATION TRUST) via R-help <r-help at r-project.org> wrote:

I am using seq with the expression seq(1.4, 2.1, by=0.001) to create a sequence of references from 1.4 to 2.1 in 0.001 increments.  They appear to be created correctly.  They have a related pair of data which for the purposes of this we will call val.  I'm interested in the content on the row with seq = 1.8. But I can't seem to get it returned.  I can get other values but not 1.8!  yet looking at row 401 there is nothing to indicate an issue

a = 1.4
b = 2.1
seq = seq(a, b, by=0.001)
val = ceiling(seq * 50)
s=data.frame(seq, val)
s$val[seq==1.799]

[1] 90

s$val[s$seq==1.8]

numeric(0)

s$val[seq==1.8]

numeric(0)

s$val[s$seq==1.800]

numeric(0)

s$val[s$seq==1.801]

[1] 91

head(s[s$seq>1.798,])

     seq val
400 1.799  90
401 1.800  90
402 1.801  91
403 1.802  91
404 1.803  91
405 1.804  91


Can anyone explain what's going on here and how I would correctly find the content of row 401 by using an expression to equal the seq column?





********************************************************************************************************************

This message may contain confidential information. If ...{{dropped:25}}