Message-ID: <1351709319.78380.YahooMailNeo@web142601.mail.bf1.yahoo.com>
Date: 2012-10-31T18:48:39Z
From: arun
Subject: HELP!! how to remove 10% of data randomly in R
In-Reply-To: <1351687340585-4647994.post@n4.nabble.com>
HI,
May be this helps.
dat1<-read.table(text="
? TDate TTime??? O3? No2 Temp Sun Wspeed Wdirect Hum Indicator
1??? 19980101? 2400 0.065 0.036 31.4 765??? 9.9??? 351? NA??????? 1
2??? 19980102? 2400 0.053 0.025 31.8 624??? 7.7??? 351? NA??????? 1
3??? 19980103? 2400 0.027 0.033 31.5 852??? 8.8??? 331? NA??????? 2
4??? 19980104? 2400 0.034 0.023 30.7 679??? 7.0??? 338? NA??????? 2
5??? 19980105? 2400 0.019 0.016 28.1 376??? 9.6??? 354? NA??????? 1
6??? 19980106? 2400 0.021 0.018 29.9 603??? 9.3??? 356? NA??????? 1
7??? 19980107? 2400 0.026 0.047 31.2 857? 10.7??? 336? NA??????? 1
8??? 19980108? 2400 0.024 0.014 31.1 635??? 7.8??? 330? NA??????? 1
9??? 19980109? 2400 0.058 0.033 32.5 742? 10.7??? 334? NA??????? 1
10? 19980110? 2400 0.026 0.032 33.9 923? 10.6??? 347? NA??????? 2
11? 19980111? 2400 0.064 0.034 32.5 751??? 6.3??? 355? NA??????? 2
12? 19980112? 2400 0.066 0.034 33.3 697??? 8.5??? 319? NA??????? 1
13? 19980113? 2400 0.026 0.030 33.4 992? 12.5??? 341? NA??????? 1
14? 19980114? 2400 0.101 0.028 33.8 705??? 8.7??? 349? NA??????? 1
15? 19980115? 2400 0.069 0.030 33.3 718? 11.4??? 348? NA??????? 1
16? 19980116? 2400 0.054 0.026 33.4 639? 10.9??? 354? NA??????? 1
17? 19980117? 2400 0.090 0.039 33.1 653? 13.2??? 342? NA??????? 2
18? 19980118? 2400 0.048 0.017 33.2 825? 10.8??? 323? NA??????? 2
19? 19980119? 2400 0.038 0.027 33.7 984? 10.3??? 353? NA??????? 1
20? 19980120? 2400 0.026 0.032 34.2 994? 15.0??? 357? NA??????? 1
21? 19980121? 2400 0.065 0.044 33.8 999? 17.5??? 343? NA??????? 1
22? 19980122? 2400 0.046 0.024 33.5 931? 10.1??? 332? NA??????? 1
23? 19980123? 2400 0.050 0.041 33.9 881? 11.3??? 353? NA??????? 1
24? 19980124? 2400 0.036 0.027 33.8 877??? 9.1??? 328? NA??????? 2
25? 19980125? 2400 0.043 0.021 33.2 777? 10.5??? 340? NA??????? 2
26? 19980126? 2400 0.029 0.016 33.1 999? 14.1??? 341? NA??????? 1
27? 19980127? 2400 0.033 0.030 33.9 943? 12.9??? 344? NA??????? 1
28? 19980128? 2400 0.040 0.022 33.7 805? 12.6??? 354? NA??????? 1
29? 19980129? 2400 0.029 0.015 30.2 512??? 7.4??? 356? NA??????? 1
30? 19980130? 2400 0.027 0.013 31.7 656? 13.9??? 349? NA??????? 1
",sep="",header=TRUE,stringsAsFactors=FALSE)
#creating NA for 10% of data in the specified columns (deviant of David's method).?
is.na(dat1[sample(1:nrow(dat1),0.1*nrow(dat1)),3:7])<-TRUE
tail(dat1)
#????? TDate TTime??? O3?? No2 Temp Sun Wspeed Wdirect Hum Indicator
#25 19980125? 2400??? NA??? NA?? NA? NA???? NA???? 340? NA???????? 2
#26 19980126? 2400 0.029 0.016 33.1 999?? 14.1???? 341? NA???????? 1
#27 19980127? 2400 0.033 0.030 33.9 943?? 12.9???? 344? NA???????? 1
#28 19980128? 2400 0.040 0.022 33.7 805?? 12.6???? 354? NA???????? 1
#29 19980129? 2400 0.029 0.015 30.2 512??? 7.4???? 356? NA???????? 1
#30 19980130? 2400 0.027 0.013 31.7 656?? 13.9???? 349? NA???????? 1
#If you need to create NA for individual columns randomly
res<-do.call(cbind,lapply(lapply(dat1[,3:7],function(x) data.frame(x)),function(x) x[sample(1:nrow(x),0.1*nrow(x)),]))
dat1[,3][dat1[,3]%in%res[,1]]<-NA
?dat1[,4][dat1[,4]%in%res[,2]]<-NA
?dat1[,5][dat1[,5]%in%res[,3]]<-NA
?dat1[,6][dat1[,6]%in%res[,4]]<-NA
dat1[,7][dat1[,7]%in%res[,5]]<-NA
?head(dat1)
#???? TDate TTime??? O3?? No2 Temp Sun Wspeed Wdirect Hum Indicator
#1 19980101? 2400 0.065 0.036 31.4 765??? 9.9???? 351? NA???????? 1
#2 19980102? 2400 0.053 0.025 31.8 624??? 7.7???? 351? NA???????? 1
#3 19980103? 2400 0.027 0.033 31.5 852??? 8.8???? 331? NA???????? 2
#4 19980104? 2400??? NA??? NA 30.7 679??? 7.0???? 338? NA???????? 2
#5 19980105? 2400 0.019 0.016 28.1 376??? 9.6???? 354? NA???????? 1
#6 19980106? 2400 0.021 0.018 29.9 603???? NA???? 356? NA???????? 1
A.K.
----- Original Message -----
From: Eugenie <leemeanwei at hotmail.com>
To: r-help at r-project.org
Cc:
Sent: Wednesday, October 31, 2012 8:42 AM
Subject: Re: [R] HELP!! how to remove 10% of data randomly in R
? tDate tTime? ? O3? No2 Temp Sun Wspeed Wdirect Hum Indicator
1? ? 19980101? 2400 0.065 0.036 31.4 765? ? 9.9? ? 351? NA? ? ? ? 1
2? ? 19980102? 2400 0.053 0.025 31.8 624? ? 7.7? ? 351? NA? ? ? ? 1
3? ? 19980103? 2400 0.027 0.033 31.5 852? ? 8.8? ? 331? NA? ? ? ? 2
4? ? 19980104? 2400 0.034 0.023 30.7 679? ? 7.0? ? 338? NA? ? ? ? 2
5? ? 19980105? 2400 0.019 0.016 28.1 376? ? 9.6? ? 354? NA? ? ? ? 1
6? ? 19980106? 2400 0.021 0.018 29.9 603? ? 9.3? ? 356? NA? ? ? ? 1
7? ? 19980107? 2400 0.026 0.047 31.2 857? 10.7? ? 336? NA? ? ? ? 1
8? ? 19980108? 2400 0.024 0.014 31.1 635? ? 7.8? ? 330? NA? ? ? ? 1
9? ? 19980109? 2400 0.058 0.033 32.5 742? 10.7? ? 334? NA? ? ? ? 1
10? 19980110? 2400 0.026 0.032 33.9 923? 10.6? ? 347? NA? ? ? ? 2
11? 19980111? 2400 0.064 0.034 32.5 751? ? 6.3? ? 355? NA? ? ? ? 2
12? 19980112? 2400 0.066 0.034 33.3 697? ? 8.5? ? 319? NA? ? ? ? 1
13? 19980113? 2400 0.026 0.030 33.4 992? 12.5? ? 341? NA? ? ? ? 1
14? 19980114? 2400 0.101 0.028 33.8 705? ? 8.7? ? 349? NA? ? ? ? 1
15? 19980115? 2400 0.069 0.030 33.3 718? 11.4? ? 348? NA? ? ? ? 1
16? 19980116? 2400 0.054 0.026 33.4 639? 10.9? ? 354? NA? ? ? ? 1
17? 19980117? 2400 0.090 0.039 33.1 653? 13.2? ? 342? NA? ? ? ? 2
18? 19980118? 2400 0.048 0.017 33.2 825? 10.8? ? 323? NA? ? ? ? 2
19? 19980119? 2400 0.038 0.027 33.7 984? 10.3? ? 353? NA? ? ? ? 1
20? 19980120? 2400 0.026 0.032 34.2 994? 15.0? ? 357? NA? ? ? ? 1
21? 19980121? 2400 0.065 0.044 33.8 999? 17.5? ? 343? NA? ? ? ? 1
22? 19980122? 2400 0.046 0.024 33.5 931? 10.1? ? 332? NA? ? ? ? 1
23? 19980123? 2400 0.050 0.041 33.9 881? 11.3? ? 353? NA? ? ? ? 1
24? 19980124? 2400 0.036 0.027 33.8 877? ? 9.1? ? 328? NA? ? ? ? 2
25? 19980125? 2400 0.043 0.021 33.2 777? 10.5? ? 340? NA? ? ? ? 2
26? 19980126? 2400 0.029 0.016 33.1 999? 14.1? ? 341? NA? ? ? ? 1
27? 19980127? 2400 0.033 0.030 33.9 943? 12.9? ? 344? NA? ? ? ? 1
28? 19980128? 2400 0.040 0.022 33.7 805? 12.6? ? 354? NA? ? ? ? 1
29? 19980129? 2400 0.029 0.015 30.2 512? ? 7.4? ? 356? NA? ? ? ? 1
30? 19980130? 2400 0.027 0.013 31.7 656? 13.9? ? 349? NA? ? ? ? 1
if given data like this,how to remove the data in O3,NO2,sun,temp,wspeed
randomly??(missing values in these rows & columns)
--
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