Let's take dataset iris and there is static value g=101. Iris dataset has 150 value. How to select exactly as many observations in the iris dataset as indicated in the variable g starting from the very first observation? As final result will be iris dataset ,but with 101 obs.

CodePudding user response：

We can use seq_len on 'g' and use as row index

g <- 101
iris_sub <- iris[seq_len(g),]

-output

> dim(iris_sub)
[1] 101   5

CodePudding user response：

in a dataframe, isn't this the basic df[1: n,] will select all records from 1 to N and all columns if none is specified. (If you have modified the data - say sorted etc and saved, it will show saved result]

so iris[1:g,] will itself work. No need for anything more with g <- 101