[R] Problem with strptime

[Dirk Eddelbuettel]

On 12 January 2008 at 16:18, Sandrine-et-Francois wrote:
| Dear R-list,
| I'm experiencing some problems while using "strptime", which I don't understand.
| 
| > str(natver)
| 'data.frame':   154 obs. of  8 variables:
|  $ ID      : Factor w/ 14 levels "AC","ALS","FA",..: 10 11 9 1 4 8 13 3 14 12 ...
|  $ CdBMin  : int  22 22 26 26 28 23 27 23 25 26 ...
|  $ CdBMax  : int  22 24 27 26 32 26 29 30 29 28 ...
|  $ Hrend   : int  184 NA 120 168 NA 152 165 160 140 140 ...
|  $ Age     : int  28 32 44 21 35 47 36 29 36 43 ...
|  $ Weight  : int  63 70 80 57 69 74 82 71 85 70 ...
|  $ variable: Factor w/ 11 levels "X50","X100","X150",..: 1 1 1 1 1 1 1 1 1 1 ...
|  $ value   : Factor w/ 47 levels "00:00:36","00:00:39",..: 1 2 4 3 3 4 5 7 8 6 ...
| > 
| > head(natver)
|    ID CdBMin CdBMax Hrend Age Weight variable    value
| 1 PHu     22     22   184  28     63      X50 00:00:36
| 2  PK     22     24    NA  32     70      X50 00:00:39
| 3  PH     26     27   120  44     80      X50 00:00:46
| 4  AC     26     26   168  21     57      X50 00:00:42
| 5  FT     28     32    NA  35     69      X50 00:00:42
| 6  OA     23     26   152  47     74      X50 00:00:46
| > 
| > natver$Time<-strptime(natver$value, format="%d/%m/%Y %H:%M:%S")
| 
| Erreur dans `$<-.data.frame`(`*tmp*`, "Time", value = list(sec = c(NA_real_,  : 
|         le tableau de remplacement a 9 lignes, le tableau remplacé en a 154


It's a FAQ. Try

    natver$Time <- as.POSIXct(strptime(natver$value, format="%d/%m/%Y %H:%M:%S"))

to cast the nine-element list of POSIXlt results generated by strptime into a
single figure POSIXct.

Amicalement, Dirk

-- 
Three out of two people have difficulties with fractions.