ffbase, help with %in%

Tue, Oct 2, 2012 6:18 AM

It doesn't seem possible to index an ff-vector using a logical  
ff-vector. You can use subset (also in ffbase) or first convert 'a' to  
a normal logical vector:


library(ff)
library(ffbase)

data1  <- as.ffdf(data.frame(a = letters[1:10], b=1:10))
data2  <- as.ffdf(data.frame(a = letters[5:26], b=5:26))

a <- data1[[1]] %in% data2$a

subset(data1, a)
data1[a[], ]


HTH,
Jan




Lucas Chaparro <lpchaparrovio at gmail.com> schreef:

Hello to everyone.
I'm trying to use the %in% to match to vectors in ff format.
a<-as.ff(data[,1]) %in% fire$fecha

aff (open) logical length=3653 (3653)

   [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]        [3646]
 FALSE  FALSE  FALSE  FALSE  FALSE  FALSE  FALSE  FALSE      :  FALSE
[3647] [3648] [3649] [3650] [3651] [3652] [3653]
 FALSE  FALSE  FALSE  FALSE  FALSE  FALSE  FALSE


Here you see a part of the data:

data[1:20,]  (just a sample, data has 3653 obs)

        fecha juliano altura  UTM.E   UTM.N
1  1990-07-01     182     15 248500 6239500
2  1990-07-02     183     15 248500 6239500
3  1990-07-03     184     15 248500 6239500
4  1990-07-04     185     15 248500 6239500
5  1990-07-05     186     15 248500 6239500
6  1990-07-06     187     15 248500 6239500
7  1990-07-07     188     15 248500 6239500
8  1990-07-08     189     15 248500 6239500
9  1990-07-09     190     15 248500 6239500
10 1990-07-10     191     15 248500 6239500
11 1990-07-11     192     15 248500 6239500
12 1990-07-12     193     15 248500 6239500
13 1990-07-13     194     15 248500 6239500
14 1990-07-14     195     15 248500 6239500
15 1990-07-15     196     15 248500 6239500
16 1990-07-16     197     15 248500 6239500
17 1990-07-17     198     15 248500 6239500
18 1990-07-18     199     15 248500 6239500
19 1990-07-19     200     15 248500 6239500
20 1990-07-20     201     15 248500 6239500

fire$fecha[1:20,] [1] "1984-11-08" "1984-11-08" "1984-11-09"  
"1984-11-09" "1984-11-09"

 [6] "1984-11-10" "1984-11-10" "1984-11-11" "1984-11-11" "1984-11-11"
[11] "1984-11-11" "1984-11-11" "1984-11-11" "1984-11-12" "1984-11-12"
[16] "1984-11-13" "1984-11-13" "1984-11-13" "1984-11-14" "1984-11-14"


to see if a got any match:


table.ff(a)


FALSE  TRUE
 1687  1966 Mensajes de aviso perdidosIn if (useNA == "no") c(NA, NaN) :
  la condici?n tiene longitud > 1 y s?lo el primer elemento ser? usado


in a regular data.frame I use data[a,] to extract the rows that a ==
TRUE, but when i do this in a ffdf i get this error:

data[a,]Error: vmode(index) == "integer" is not TRUE


I'm just learning how to use the ff package so, obviously I'm  
missing something


If any of you knows how to solve this, please teach me.

Thank you so much.


Lucas.

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ffbase, help with %in%

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