How to Cross-Paste All Combinations of Two Vectors (Each-To-Each)

How to cross-paste all combinations of two vectors (each-to-each)?

You can also do:

outer(c("a", "b"), c("c", "d"), FUN = "paste0")[1:4]
[1] "ac" "bc" "ad" "bd"

Both do.call and outer are valuable functions to play with. :)

Alternately, we can assign

x <- outer(c("a", "b"), c("c", "d"), FUN = "paste0")
dim(x) <- NULL
x
[1] "ac" "bc" "ad" "bd"

Without knowing the length.

More edits!

x <- outer(c("a", "b"), c("c", "d"), FUN = "paste0")
y <- t(x)
dim(y) <- NULL
y
[1] "ac" "ad" "bc" "bd"

Gets you the desired order, too.

Pasting two vectors with combinations of all vectors' elements

You can use this, but there may be a simpler solution :

R> apply(expand.grid(vars, vis), 1, paste, collapse=".")
[1] "SR.1" "PL.1" "SR.2" "PL.2" "SR.3" "PL.3"

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expand.grid gives back a data.frame which when used with apply, apply will convert it to a matrix. This is just unnecessary (and inefficient on large data). outer gives a matrix and also takes function argument. It'll be much efficient on huge data as well.

Using outer:

as.vector(outer(vars, vis, paste, sep="."))
# [1] "SR.1" "PL.1" "SR.2" "PL.2" "SR.3" "PL.3"

Paste all combinations of two separate vectors in R

Another approach:

df1 <- c("a","b","c")
df2 <- c("1","2","3")

apply(expand.grid(df1, df2), 1, paste, collapse="")

Rowbinding all combinations of two vectors for each variation in a third vector

Maybe this helps

out <- rbind(rep(down, each = length(cat)), rep(up, each = length(cat)))
colnames(out) <- rep(c(cat), length.out = ncol(out))
row.names(out) <- c('down', 'up')

-output

> out
     east north south west east north south west east north south west east north south west east north south west east north south west east north south west east
down    0     0     0    0   25    25    25   25   50    50    50   50  100   100   100  100  250   250   250  250  500   500   500  500 1000  1000  1000 1000 1500
up     25    25    25   25   50    50    50   50  100   100   100  100  250   250   250  250  500   500   500  500 1000  1000  1000 1000 1500  1500  1500 1500 3000
     north south west    east   north   south    west
down  1500  1500 1500    3000    3000    3000    3000
up    3000  3000 3000 1000000 1000000 1000000 1000000

Create list from two vectors with every combo of each

Since you have data.table as a package, you can use the CJ() cross join function:

CJ(cycles, thedates)

It would be a lot faster than expand.grid:

expand.grid(cycles, thedates)

I also think having a bunch of lists isn't helpful but you could split it as @Reeza provided to match your output.

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