How can I modify seq() to generate a list of 12 numeric vectors, each vector containing the months that appear every 3 months from the month of interest?
I require each month to have at least 3 values in each vector. I'm unsure how to recycle the values 1 through 12 in my current use of seq. Any guidance would be much appreciated!
# create every three month values
list.of.month.values <-
list( JAN = 1
, FEB = 2
, MAR = 3
, APR = 4
, MAY = 5
, JUN = 6
, JUL = 7
, AUG = 8
, SEP = 9
, OCT = 10
, NOV = 11
, DEC = 12 )
# find each month's
# values that appear every three months
every.three.month.values <-
lapply(
X = list.of.month.values
, FUN = function( i )
seq( from = i, to = 12, by = 3 )
)
# view results
every.three.month.values
# $JAN
# [1] 1 4 7 10
#
# $FEB
# [1] 2 5 8 11
#
# $MAR
# [1] 3 6 9 12
#
# $APR
# [1] 4 7 10
#
# $MAY
# [1] 5 8 11
#
# $JUN
# [1] 6 9 12
#
# $JUL
# [1] 7 10
#
# $AUG
# [1] 8 11
#
# $SEP
# [1] 9 12
#
# $OCT
# [1] 10
#
# $NOV
# [1] 11
#
# $DEC
# [1] 12
# This works for the first 6 months.
# But we need all twelve months
every.three.month.values$JUL <- c( 7, 10, 1 )
every.three.month.values$AUG <- c( 8, 11, 2 )
every.three.month.values$SEP <- c( 9, 12, 3 )
every.three.month.values$OCT <- c( 10, 1, 4 )
every.three.month.values$NOV <- c( 11, 2, 5 )
every.three.month.values$DEC <- c( 12, 3, 6 )
# end of script #
Here is my desired output:
structure(list(JAN = c(1, 4, 7, 10), FEB = c(2, 5, 8, 11), MAR = c(3,
6, 9, 12), APR = c(4, 7, 10), MAY = c(5, 8, 11), JUN = c(6, 9,
12), JUL = c(7, 10, 1), AUG = c(8, 11, 2), SEP = c(9, 12, 3),
OCT = c(10, 1, 4), NOV = c(11, 2, 5), DEC = c(12, 3, 6)), .Names = c("JAN",
"FEB", "MAR", "APR", "MAY", "JUN", "JUL", "AUG", "SEP", "OCT",
"NOV", "DEC"))
You could do something like this:
df <- sapply(seq(1, 12, by = 3), function(x)
((seq(x, 12 + x - 1, by = 1) - 1) %% 12) + 1);
rownames(df) <- names(list.of.month.values);
# [,1] [,2] [,3] [,4]
#JAN 1 4 7 10
#FEB 2 5 8 11
#MAR 3 6 9 12
#APR 4 7 10 1
#MAY 5 8 11 2
#JUN 6 9 12 3
#JUL 7 10 1 4
#AUG 8 11 2 5
#SEP 9 12 3 6
#OCT 10 1 4 7
#NOV 11 2 5 8
#DEC 12 3 6 9
Note that this is not exactly the same as your expected outcome; I don't understand the logic behind why in your output JAN, FEB and MAR have 4 elements, but the rest of the months have only 3 elements.
You can reproduce your expected output by doing
lst <- apply(df, 1, function(x) if (x[1] < 4) x else x[-length(x)]);
names(lst) <- names(list.of.month.values);
#$JAN
#[1] 1 4 7 10
#
#$FEB
#[1] 2 5 8 11
#
#$MAR
#[1] 3 6 9 12
#
#$APR
#[1] 4 7 10
#
#$MAY
#[1] 5 8 11
#
#$JUN
#[1] 6 9 12
#
#$JUL
#[1] 7 10 1
#
#$AUG
#[1] 8 11 2
#
#$SEP
#[1] 9 12 3
#
#$OCT
#[1] 10 1 4
#
#$NOV
#[1] 11 2 5
#
#$DEC
#[1] 12 3 6
but this seems unnecessarily ugly/kludgy.