Hi, Based on the information you provided, the solution should be the one I provided earlier. Otherwise, I must have misunderstood your question. In your first post, you mentioned the IDs range from 5:200. So, the question is not clear.
dat1<- read.table(text=" timeSec pupilId pupilName 137237 57 LaurenColes 137250 57 LaurenColes 137254 59 JackGough 137262 57 LaurenColes 137275 92 GraceChapman 137281 59 JackGough 137285 111 DavidHenderson 137291 57 LaurenColes 137297 92 GraceChapman 137305 68 AmeliaNorth 137306 82 AlexBruce 137309 92 GraceChapman 137311 111 DavidHenderson 137325 57 LaurenColes 137328 82 AlexBruce 137329 68 AmeliaNorth 137330 111 DavidHenderson 137330 104 SofiaMorrison 137335 15 KieraNoble 137340 34 LouisTalbot 137342 20 EllaOConnor 137345 68 AmeliaNorth 137346 57 LaurenColes 137349 65 AmeliaMiller 137351 40 KatieWinter 137353 34 LouisTalbot 137357 115 NoahStorey 137357 92 GraceChapman ",sep="",header=TRUE,stringsAsFactors=FALSE) IDs<-1:161 setdiff(IDs,dat1$pupilId) # [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 16 17 18 19 # [19] 21 22 23 24 25 26 27 28 29 30 31 32 33 35 36 37 38 39 # [37] 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 58 60 # [55] 61 62 63 64 66 67 69 70 71 72 73 74 75 76 77 78 79 80 # [73] 81 83 84 85 86 87 88 89 90 91 93 94 95 96 97 98 99 100 # [91] 101 102 103 105 106 107 108 109 110 112 113 114 116 117 118 119 120 121 #[109] 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 #[127] 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 #[145] 158 159 160 161 sum(setdiff(IDs,dat1$pupilId)) #[1] 12179 length(setdiff(IDs,dat1$pupilId)) #changes when you use the actual dataset #[1] 148 A.K. Sorry, this is my first time I am using the forum. The data I have is the following: timeSec pupilId pupilName 137237 57 LaurenColes 137250 57 LaurenColes 137254 59 JackGough 137262 57 LaurenColes 137275 92 GraceChapman 137281 59 JackGough 137285 111 DavidHenderson 137291 57 LaurenColes 137297 92 GraceChapman 137305 68 AmeliaNorth 137306 82 AlexBruce 137309 92 GraceChapman 137311 111 DavidHenderson 137325 57 LaurenColes 137328 82 AlexBruce 137329 68 AmeliaNorth 137330 111 DavidHenderson 137330 104 SofiaMorrison 137335 15 KieraNoble 137340 34 LouisTalbot 137342 20 EllaOConnor 137345 68 AmeliaNorth 137346 57 LaurenColes 137349 65 AmeliaMiller 137351 40 KatieWinter 137353 34 LouisTalbot 137357 115 NoahStorey 137357 92 GraceChapman etc... The exact quesiton is the following: Some ids in the range 1 to 161 are unused (e.g. 4,7,9). In fact, there are 30 unused pupil Ids between 1 and 161. What is the sum of these 30 integers? ----- Original Message ----- From: arun <smartpink...@yahoo.com> To: R help <r-help@r-project.org> Cc: Sent: Wednesday, June 19, 2013 9:26 AM Subject: Re: Elementary Help HI, Probably, this is the case. It is better to provide a reproducible example data as mentioned in the posting guide. set.seed(24) dat1<- data.frame(ID=c(1:3,5:8,10:14),value=sample(1:40,12,replace=TRUE)) IDs<- 1:14 #the possible ID list setdiff(IDs,dat1$ID) #[1] 4 9 length(setdiff(IDs,dat1$ID)) #[1] 2 A.K. Hi, Unfortunately somehow it won't help. The unused values are not NA, the unused values are simply not there. Since these are student Ids, for instance there is no 4,8,9 etc... I need to find out which of these are not there. ----- Original Message ----- From: arun <smartpink...@yahoo.com> To: R help <r-help@r-project.org> Cc: Sent: Tuesday, June 18, 2013 10:32 AM Subject: Re: Elementary Help Hi, May be this helps: set.seed(24) dat1<- data.frame(ID=1:200,value=sample(c(5:200,NA),200,replace=TRUE)) which(is.na(dat1$value)) #[1] 56 146 184 sum(which(is.na(dat1$value))) #Not clear about the 2nd part of the question #[1] 386 sum(is.na(dat1$value)) #[1] 3 table(is.na(dat1$value)) #FALSE TRUE # 197 3 A.K. >I am totally new to R, therefore probably this question will be very easy for most of you. I have a range of values in a column ranging from 5 to 200. >Some of the values are missing, that is, not all student numbers are there. How do I find which are these missing numbers and obtain the sum of >these integers? ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
