How to successively combine years and months using purrr

[BHM]

Hi, 

-----------------------------------

PROBLEM STATEMENT

-----------------------------------

I want to generate URLS for each month for each year as follows:

[...]

https://s3.amazonaws.com/data/201611.csv.zip

https://s3.amazonaws.com/data/201612.csv.zip

https://s3.amazonaws.com/data/201701.csv.zip

https://s3.amazonaws.com/data/201702.csv.zip

[...]

-----------------------------------

CODE

-----------------------------------

Here is my attempt:

head.f.name = "https://s3.amazonaws.com/data/%sA"

tail.f.name = ".csv.zip"

v.i = str_pad(1:12,2,pad="0") 

map_chr(2015:2017, ~sprintf(head.f.name,.)) %>%

  map2_chr(v.i,~str_replace(.,"[:upper:]$") )

-----------------------------------

ERROR 

-----------------------------------

But I get an error:

Error: `.x` (3) and `.y` (12) are different lengths

Should not the smaller vector be recycled in this case.

Br / 

[Ista Zahn]

On Thu, Apr 27, 2017 at 10:57 AM, BHM <ulh...@gmail.com> wrote:
> Hi,
>
> -----------------------------------
> PROBLEM STATEMENT
> -----------------------------------
> I want to generate URLS for each month for each year as follows:
>
> [...]
> https://s3.amazonaws.com/data/201611.csv.zip
> https://s3.amazonaws.com/data/201612.csv.zip
> https://s3.amazonaws.com/data/201701.csv.zip
> https://s3.amazonaws.com/data/201702.csv.zip
> [...]
>
> -----------------------------------
> CODE
> -----------------------------------
> Here is my attempt:
>
> head.f.name = "https://s3.amazonaws.com/data/%sA"
> tail.f.name = ".csv.zip"
> v.i = str_pad(1:12,2,pad="0")
>
> map_chr(2015:2017, ~sprintf(head.f.name,.)) %>%
> map2_chr(v.i,~str_replace(.,"[:upper:]$") )
>

That seems more complicated than it needs to be. How about

> years <- 2015L:2017L
> months <- str_pad(1:12,2,pad="0")
> str_c("https://s3.amazonaws.com/data/", years, rep(months, length(years)), ".csv.zip")


?

>
> -----------------------------------
> ERROR
> -----------------------------------
> But I get an error:
> Error: `.x` (3) and `.y` (12) are different lengths
>
>
> Should not the smaller vector be recycled in this case.

No, see ?map2

Best,
Ista
>
>
>
>
> Br /
>
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[Burhan ul haq]

1. Thanks for the suggestion - It works :) 

2. For map2 - you are right, it says:

.x, .y

Vectors of the same length. A vector of length 1 will be recycled.

Br / 

> email to manipulatr+unsubscribe@googlegroups.com.