CODEWITHSUNDEEP
rmapply
CodePrinz
CodePrinz

Reputation: 497

Use mapply for multiple vectors but only once for each element

I try to iterate over multiple vectors like Pythons "for x, y, z in zip(lia, lib, lic): ..." and found mapply which does what I want, but it returns too much.

Example:

lia = c(1,2,3)
lib = c(4,5,6)
lic = c(7,8,9)
mapply(function(x, y, z) print(sprintf('%f %f %f', x, y, z)), lia, lib, lic )

Results in:

[1] "1.000000 4.000000 7.000000"
[1] "2.000000 5.000000 8.000000"
[1] "3.000000 6.000000 9.000000"
[[1]]
[1] "1.000000 4.000000 7.000000"

[[2]]
[1] "2.000000 5.000000 8.000000"

[[3]]
[1] "3.000000 6.000000 9.000000"

The first three lines are what I expect. Why it is returning more? How would I do it correctly?

Upvotes: 1

Views: 180

Answers (1)

jay.sf
jay.sf

Reputation: 72909

When you use print, mapply still has it's own output which you may make invisible. However, maybe you don't need print at all.

Try one of the two:

invisible(mapply(function(x, y, z) print(sprintf('%f %f %f', x, y, z)), lia, lib, lic))
# [1] "1.000000 4.000000 7.000000"
# [1] "2.000000 5.000000 8.000000"
# [1] "3.000000 6.000000 9.000000"

mapply(function(x, y, z) sprintf('%f %f %f', x, y, z), lia, lib, lic)
# [1] "1.000000 4.000000 7.000000" "2.000000 5.000000 8.000000" "3.000000 6.000000 9.000000"

Upvotes: 1

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