[R] Help me please: gplot, facets_wrap and ordering of x axis dates

[David Lyon]

I have a text file of data as below and doing a ggplot line plot of all the ids as separate mini line plots which works with the following code.

Problem how do I order the dates for each id plot on the x axis so that the dates are going from oldest to most recent????


Thanks in advance

Dave





CODE:

a<-read.table("DATA",header=TRUE);
b<-a[order(as.Date(a$date, format="%m/%d/%Y")),]

ggplot(data=b) + geom_line(aes(x=date, y=value, group=id, colour= factor(id))) + facet_wrap(~id, scales = "free")






DATA:


id      date    value
001     8/16/10 <0.16
001     10/25/10        <0.16
001     11/8/10 0.42
001     11/22/10        0.81
001     12/6/10 <0.16
002     8/18/10 2.93
002     10/25/10        2.4
002     11/8/10 1.36
002     11/22/10        1.22
004     8/20/10 0.77
004     10/25/10        0.85
004     11/8/10 1.22
004     11/22/10        0.21
004     12/6/10 1.81
004     10/26/11        0.54
005     6/4/09  1.33
005     6/18/10 1.32
005     8/25/10 2.5
005     9/15/10 1.3
005     10/25/10        1.1
005     11/8/10 0.66
005     11/22/10        0.84
005     12/6/10 7.42
005     11/4/11 1.21
006     9/23/10 0.97
006     10/25/10        2.25
006     11/8/10 0.51
006     11/22/10        0.53
006     12/6/10 0.41
008     8/25/10 3.14
008     10/25/10        3.58
008     11/8/10 2.41
008     12/6/10 2.08
008     6/11/12 3.2
009     10/6/10 0.24
009     11/22/10        0.34
009     2/2/11  0.58
009     2/16/11 0.54
009     3/2/11  0.25
009     3/16/11 0.39
010     9/14/10 0.28
010     2/2/11  0.19
010     2/16/11 0.42
010     3/2/11  0.39
010     3/16/11 0.26
011     8/20/10 <0.16
011     2/2/11  <0.16
011     2/16/11 <0.16
011     3/2/11  <0.16
011     3/16/11 1.76
011     10/26/11        <0.16
012     12/14/10        0.48
012     2/2/11  1.2
012     2/16/11 0.44
012     3/2/11  0.32
012     3/16/11 0.34
013     11/13/09        0.73
013     8/19/10 3.32
013     2/2/11  13.7
014     2/6/13  1.35
014     4/24/13 0.85
014     8/18/10 0.66
014     10/5/10 0.68
014     10/27/10        0.53
014     2/2/11  0.54
014     2/16/11 0.49
014     3/2/11  0.31
014     3/16/11 0.4
014     6/29/11 0.53
014     8/15/11 0.55
014     8/15/12 0.94
014     10/31/12        0.74
015     12/10/10        0.4
015     2/2/11  0.44
015     3/2/11  0.38
015     3/16/11 0.43
016     12/17/10        0.18
016     1/25/11 <0.16
016     2/2/11  0.53
016     2/2/11  0.54
016     2/16/11 0.46
016     3/2/11  0.29
016     3/16/11 0.2
016     3/20/12 0.18
016     3/26/12 0.23
016     3/30/12 0.52
016     4/2/12  0.33
016     4/23/12 0.3
017     11/17/11        3.35
017     12/9/11 2.56
018     2/25/13 18.1
018     3/11/13 14.9
018     3/25/13 11.1
018     4/10/13 8.47
018     4/22/13 15.9