r - Expand data.frame into distinct rows -

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• r creating sequence table 2 columns 4 answers

i trying figure out how can expand data.frame in r distinct rows. this, mean using startyear , toyear variables create annual data.frame id replicated each distinct year in sequence from=startyear to=endyear.

i have example data.frame:

testdat <- data.frame(id=seq(1,10),            startyear=c(1946,1960,1965,1976,1955,1999,2013,1981,1983,1995)            )  testdat$endyear <- testdat$startyear+sample(1:10,10,replace=true) 

this creates:

  id startyear endyear 1  1      1946    1951 2  2      1960    1966 3  3      1965    1969 .  .      ....    .... 

what desired result this:

id year 1  1946 1  1947 1  1948 1  1949 1  1950 1  1951 2  1960 .  .... 

any advice on how great. thanks.

try "hadley'verse", namely dplyr , tidyr:

library(dplyr) library(tidyr) testdat %>%    group_by(id) %>%   expand(year=full_seq(c(startyear, endyear), 1)) # source: local data frame [64 x 2] # groups: id [10] #  #       id  year #    (int) (dbl) # 1      1  1946 # 2      1  1947 # 3      1  1948 # 4      1  1949 # 5      1  1950 # 6      1  1951 # 7      1  1952 # 8      2  1960 # 9      2  1961 # 10     3  1965 # ..   ...   ...