Hi, I have a vector of time in days t<-1:48. I have observations and the day they were recorded. I also have a vector, S which takes different values depending on which day the observation was recorded. For example if on day 1 all in vector S get a value of 46/48, on day 2 get 42/48, day 3 38/48, decreasing by 4/48 each time until day 12 gets the value 2/48. Then for any day greater than 12 the vector S has value 0. I want to create a vector which gives the values of S in terms of days, t. I have tried: t<-1:48 for(i in 1:t){ S<-rep(0,48) if(t<12){ S[i]<-(48-3*t)/48} else{ S[i]<-0} } but this doesn't work. I'm fairly new to R and don't have much skill in manipulating things. I'm trying to plot time against this vector so need it in terms of t. Sorry that this isn't even very clear in what I want and I'm aware that the (48-3*t)/48 won't even give me the 46/48,42/48,38/48....2/48,0....0 pattern I'm after but no idea what to do! Any help would be great. Thanks -- View this message in context: http://r.789695.n4.nabble.com/Vector-manipulation-for-loop-needed-tp2260334p2260334.html Sent from the R help mailing list archive at Nabble.com.
On Jun 18, 2010, at 10:52 AM, clips10 wrote:> > Hi, > > I have a vector of time in days t<-1:48. > > I have observations and the day they were recorded. I also have a > vector, S > which takes different values depending on which day the observation > was > recorded. For example if on day 1 all in vector S get a value of > 46/48, on > day 2 get 42/48, day 3 38/48, decreasing by 4/48 each time until day > 12 gets > the value 2/48. Then for any day greater than 12 the vector S has > value 0. > > I want to create a vector which gives the values of S in terms of > days, t. > I have tried: > > t<-1:48 > for(i in 1:t){ > S<-rep(0,48) > if(t<12){ > S[i]<-(48-3*t)/48} > else{ > S[i]<-0} > }> t<- 1:48; x <- ifelse( (50-t*4)> 0 , (50-t*4)/48, 0) ; x [1] 0.95833333 0.87500000 0.79166667 0.70833333 0.62500000 0.54166667 [7] 0.45833333 0.37500000 0.29166667 0.20833333 0.12500000 0.04166667 [13] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 [19] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 [25] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 [31] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 [37] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 [43] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000> > but this doesn't work. I'm fairly new to R and don't have much skill > in > manipulating things. I'm trying to plot time against this vector so > need it > in terms of t. Sorry that this isn't even very clear in what I want > and I'm > aware that the (48-3*t)/48 won't even give me the > 46/48,42/48,38/48....2/48,0....0 pattern I'm after but no idea what > to do!Close, just not quite there. Try: (50-4*t)/48> > Any help would be great. > ThanksDavid Winsemius, MD West Hartford, CT
?ifelse HTH, Jorge On Fri, Jun 18, 2010 at 10:52 AM, clips10 <> wrote:> > Hi, > > I have a vector of time in days t<-1:48. > > I have observations and the day they were recorded. I also have a vector, S > which takes different values depending on which day the observation was > recorded. For example if on day 1 all in vector S get a value of 46/48, on > day 2 get 42/48, day 3 38/48, decreasing by 4/48 each time until day 12 > gets > the value 2/48. Then for any day greater than 12 the vector S has value 0. > > I want to create a vector which gives the values of S in terms of days, t. > I have tried: > > t<-1:48 > for(i in 1:t){ > S<-rep(0,48) > if(t<12){ > S[i]<-(48-3*t)/48} > else{ > S[i]<-0} > } > > but this doesn't work. I'm fairly new to R and don't have much skill in > manipulating things. I'm trying to plot time against this vector so need it > in terms of t. Sorry that this isn't even very clear in what I want and I'm > aware that the (48-3*t)/48 won't even give me the > 46/48,42/48,38/48....2/48,0....0 pattern I'm after but no idea what to do! > > Any help would be great. > Thanks > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Vector-manipulation-for-loop-needed-tp2260334p2260334.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. >[[alternative HTML version deleted]]