[R] Filling a variable with unmentioned categories

[jim holtman]

will this work for you:

> str(x)
'data.frame':   10 obs. of  2 variables:
 $ price    : chr  "0,00" "0,00" "0,02" "0,03" ...
 $ mentioned: int  1 1 1 1 1 1 1 1 1 1
> # create vector with range of 'price'
> allPrices <- paste('0,', sprintf("%02d", 0:19), sep = '')
> # find missing prices and add with mentioned = 0
> newX <- rbind(x
+     , data.frame(price = setdiff(allPrices, x$price)
+                 , mentioned = 0
+                 , stringsAsFactors = FALSE
+                 )
+     )
> newX[order(newX$price),]
   price mentioned
1   0,00         1
2   0,00         1
11  0,01         0
3   0,02         1
4   0,03         1
5   0,03         1
6   0,04         1
12  0,05         0
13  0,06         0
14  0,07         0
15  0,08         0
16  0,09         0
7   0,10         1
17  0,11         0
18  0,12         0
19  0,13         0
20  0,14         0
21  0,15         0
8   0,16         1
22  0,17         0
23  0,18         0
9   0,19         1
10  0,19         1
>


On Fri, Nov 18, 2011 at 12:05 PM, Milan Bouchet-Valat <nalimilan at club.fr> wrote:
> Le vendredi 18 novembre 2011 à 15:06 +0000, Mario Giesel a écrit :
>> Hello, list,
>>
>> I've been struggling with this task for a while looking for an efficient way to solve it:
>> There are two variables 'price' and 'mentioned'.
>> I want to 'enlarge' data so that missing price points within the price range are added to variable price.
>> Also variable 'mentioned' is to receive values 0 in these cases.
>> Note: Price points in original data can repeat if several persons mentioned that price point.
> Let's say prices1 holds the first list of prices, prices2 the
> supplementary one. Try:
> prices <- c(prices1, prices2)
> prices <- sort(prices[!duplicated(prices)])
> data.frame(price=prices, mentioned=prices %in% prices1)
>
> Regards
>
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-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.