[R] ffbase, help with %in%

[Jan van der Laan]

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 condición tiene longitud > 1 y sólo el primer elemento será 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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