[R] dplyr help

[David Winsemius]

On Jul 29, 2015, at 7:37 PM, Jon BR wrote:

> Hello,
>    I've recently discovered the helpful dplyr package.  I'm using the
> 'aggregate' function as such: 

The `aggregate` function is part of base-R:

> bevs <- data.frame(cbind(name = c("Bill", "Mary"), drink = c("coffee",
> "tea", "cocoa", "water"), cost = seq(1:8), sex = c("male","female")));
> bevs$cost <- seq(1:8)
> 
>> bevs
>  name  drink cost    sex
> 1 Bill coffee    1   male
> 2 Mary    tea    2 female
> 3 Bill  cocoa    3   male
> 4 Mary  water    4 female
> 5 Bill coffee    5   male
> 6 Mary    tea    6 female
> 7 Bill  cocoa    7   male
> 8 Mary  water    8 female
>> 
> 
>> aggregate(cost ~ name + drink, data = bevs, sum)
>  name  drink cost
> 1 Bill  cocoa   10
> 2 Bill coffee    6
> 3 Mary    tea    8
> 4 Mary  water   12
> 
> My issue is that I would like to keep a column for 'sex', for which there
> is a 1:1 mapping with 'name', such that every time 'Bill' appears, it is
> always 'male'.
> 
> Does anyone know of a way to accomplish this, with or without dplyr?

As pointed out you have not yet demonstrated any dplyr functions.

> The
> ideal command(s) would produce this:
> 
>  name  drink cost sex
> 1 Bill  cocoa   10   male
> 2 Bill coffee    6   male
> 3 Mary    tea    8   female
> 4 Mary  water   12   female

Doesn't this (glaringly obvious?) approach succeed?

> aggregate(cost ~ name + drink+sex, data = bevs, sum)
  name  drink    sex cost
1 Mary    tea female    8
2 Mary  water female   12
3 Bill  cocoa   male   10
4 Bill coffee   male    6
> 


> 
> I would be thankful for any suggestion!
> 
> Thanks,
> Jonathan
> 
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> 
> 

Please learn to post in plain text.

-- 

David Winsemius
Alameda, CA, USA