how to use dcast on a dataframe that has only 1 row in R -

hi have dataframe

start <- c("a") end <- c("c") days <- c("day1")  df2 <- data.frame(start,end,days)

i trying use dcast

df2 <- dcast(df2,days ~ end,value.var="days")

but returns

  days    c 1 day1 day1

my desired output count

  days    c 1 day1    1

what missing here? kindly provide inputs on this. there better way using dplyr?

we can create sequence column of 1 , use dcast

 dcast(transform(df2, i1=1), days~end, value.var='i1') #  days c #1 day1 1

or option using fun.aggregate

dcast(df2, days~end, length) #  days c #1 day1 1

as op mentioned dplyr, involves using first method doesn't have fun.aggregate

 library(dplyr)  df2 %>%     mutate(c=1) %>%     select(days:c)

Scrio