cbind warnings : row names were found from a short variable and have been discarded
I have below line of code for cbind, but I am getting a warning message everytime. Though the code still functions as it should be, is there any way to resolve the warning?
dateset = subset(all_data[,c("VAR1","VAR2","VAR3","VAR4","VAR5","RATE1","RATE2","RATE3")])
dateset = cbind(dateset[c(1,2,3,4,5)],stack(dateset[,-c(1,2,3,4,5)]))
Warnings :
Warning message:
In data.frame(..., check.names = FALSE) :
row names were found from a short variable and have been discarded
Thanks in advance!
Answer
I'm guessing your data.frame has row.names:
A <- data.frame(a = c("A", "B", "C"),
b = c(1, 2, 3),
c = c(4, 5, 6),
row.names=c("A", "B", "C"))
cbind(A[1], stack(A[-1]))
# a values ind
# 1 A 1 b
# 2 B 2 b
# 3 C 3 b
# 4 A 4 c
# 5 B 5 c
# 6 C 6 c
# Warning message:
# In data.frame(..., check.names = FALSE) :
# row names were found from a short variable and have been discarded
What's happening here is that since you can't by default have duplicated row.names in a data.frame and since you don't tell R at any point to duplicate the row.names when recycling the first column to the same number of rows of the stacked column, R just discards the row.names.
Compare with a similar data.frame, but one without row.names:
B <- data.frame(a = c("A", "B", "C"),
b = c(1, 2, 3),
c = c(4, 5, 6))
cbind(B[1], stack(B[-1]))
# a values ind
# 1 A 1 b
# 2 B 2 b
# 3 C 3 b
# 4 A 4 c
# 5 B 5 c
# 6 C 6 c
Alternatively, you can set row.names = NULL in your cbind statement:
cbind(A[1], stack(A[-1]), row.names = NULL)
# a values ind
# 1 A 1 b
# 2 B 2 b
# 3 C 3 b
# 4 A 4 c
# 5 B 5 c
# 6 C 6 c
If your original row.names are important, you can also add them back in with:
cbind(rn = rownames(A), A[1], stack(A[-1]), row.names = NULL)
# rn a values ind
# 1 A A 1 b
# 2 B B 2 b
# 3 C C 3 b
# 4 A A 4 c
# 5 B B 5 c
# 6 C C 6 c