Question

I have a dataframe with ten columns:

A  B   C   1  1  1  1  1  1  1
B  M   J   2  1  2  2  2  2  2
J  K   Z   3  3  3  3  3  3  3.1
V  N   I   4  4  4  4  4  4  4

I want to exclude those rows that have the same value from 4 to 10 column. I found solution for comparing different rows but here I am talking about within 1 row. So output is

B  M   J   2  1  2  2  2  2  2
J  K   Z   3  3  3  3  3  3  3.1

because 1st and last row has same values in columns 4 to 10. I can do it by comparing each value 1 by 1 but my dataframe is very big (~100,000 rows).

Answer 1

What about something like:

 ##Work out the rows to keep
 ##dd is your data frame
 rows = apply(dd[, 4:10], 1, function(i) length(unique(i)) > 1)

then subset as normal

 dd[rows,]

~100K rows isn’t that much.