[R] assign multiple variables at once

[Hosack, Michael]

R Experts,

I would like to create a series of variables without having 
to assign a separate line of code for each new variable. My dataframe (DF) contains 
two groups of linked variables (ESP1:ESP9) and (ECRL1:ECRL9). Within ESP1:ESP9 are
abbreviated species codes (full dataframe contains 26 codes). ECRL1 represents the 
number of species x in variable ESP1 harvested, and so on through ESP9 and ECRL9. 
What I want to do is create 26 new variables (one for each unique species code) that 
contains the number harvested (ECRL) for each corresponding species code listed for
each row of the data set. Example (row 14), the new variable YP Harvest would equal 
90 (ECRL2) and WP Harvest would equal 0 (ECRL1), all other species code var's would 
contain NA. 

I hope I made this clear enough.

Thank you,

Mike

Current method: one line per species

EBTCH1.h$YP.H <- with(EBTCH1.h,ifelse(ESP1 %in% 'YP',ECRL1,ifelse(ESP2 %in% 'YP',ECRL2,
ifelse(ESP3 %in% 'YP',ECRL3,ifelse(ESP4 %in% 'YP',ECRL4,ifelse(ESP5 %in% 'YP',ECRL5,
ifelse(ESP6 %in% 'YP',ECRL6,ifelse(ESP7 %in% 'YP',ECRL7,ifelse(ESP8 %in% 'YP',ECRL8,
ifelse(ESP9 %in% 'YP',ECRL9,0))))))))))


DF <-
structure(list(MM = c(5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
5L, 5L, 5L, 5L, 5L), DD = c(3L, 3L, 3L, 3L, 3L, 3L, 7L, 7L, 7L, 
8L, 8L, 8L, 8L, 8L, 8L), DTYPE = c(2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1, 1, 1, 1), TOD = c(2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1), SITENUM = c("102", "104", "104", "104", "101", "101", 
"102", "103", "101", "101", "101", "101", "103", "103", "103"
), CURTIM = c(1450L, 1736L, 1755L, 1804L, 1950L, 2007L, 1150L, 
1450L, 2000L, 1003L, 1030L, 1036L, 1300L, 1310L, 1320L), GRPFSH = c(2L, 
2L, 2L, 2L, 2L, 3L, 1L, 2L, 3L, 2L, 4L, 1L, 1L, 3L, 1L), EEFF = c(11.5, 
19, 5, 20, 0, 0, 5, 8, 0, 0, 0, 0, 3, 12, 6), ESP1 = c("SMB", 
"SMB", "SMB", "SMB", NA, NA, "YP", "YP", NA, NA, NA, NA, "RG", 
"WP", "WP"), ESP2 = c(NA, "RB", NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, "SMB", "YP", "YP"), ESP3 = c(NA, NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA, "RB", "RBS", NA), ESP4 = c(NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, 
NA_character_, NA_character_, NA_character_, NA_character_), 
    ESP5 = c(NA_character_, NA_character_, NA_character_, NA_character_, 
    NA_character_, NA_character_, NA_character_, NA_character_, 
    NA_character_, NA_character_, NA_character_, NA_character_, 
    NA_character_, NA_character_, NA_character_), ESP6 = c(NA, 
    NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), 
    ESP7 = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 
    NA, NA, NA), ESP8 = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, 
    NA, NA, NA, NA, NA, NA), ESP9 = c(NA, NA, NA, NA, NA, NA, 
    NA, NA, NA, NA, NA, NA, NA, NA, NA), ECRL1 = c(0L, 0L, 0L, 
    0L, 0L, 0L, 4L, 5L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), ECRL2 = c(0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 90L, 30L), 
    ECRL3 = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L), ECRL4 = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L), ECRL5 = c(0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), ECRL6 = c(0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), ECRL7 = c(0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), 
    ECRL8 = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L), ECRL9 = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L)), .Names = c("MM", "DD", "DTYPE", 
"TOD", "SITENUM", "CURTIM", "GRPFSH", "EEFF", "ESP1", "ESP2", 
"ESP3", "ESP4", "ESP5", "ESP6", "ESP7", "ESP8", "ESP9", "ECRL1", 
"ECRL2", "ECRL3", "ECRL4", "ECRL5", "ECRL6", "ECRL7", "ECRL8", 
"ECRL9"), row.names = c(NA, 15L), class = "data.frame")