search for: srswor

...g three methods and now i want to calculate the statistics but i only get the population parameters.   H <- matrix(rnorm(100, mean=50000, sd=5000)) sampleframe=data.frame(type=c(rep("H",100)),value=c(H)) sampleframe   str=strata(sampleframe,c("type"),size=c(20,), method="srswor") sample.strat<-getdata(sampleframe,str) sample.strat length(H) i get:   length(H) [1] 100 Desire to get: length(H) [1] 20   Best Regards     [[alternative HTML version deleted]]

...atified random samples from a population of >3900 cells. I have 41 strata and I have to draw a different number of samples from them(between 2 and 8). I have tried to apply the funtion strata following the instruction in the manual: strata(dataframe, stratanames=NULL, size, method=c("srswor"), pik,description=TRUE) but I get the error message Error in data.frame((1:nrow(data))[srswor(size, nrow(data)) == 1], rep(size/nrow(data), : arguments imply differing number of rows: 3, 122 My stratanames and size vectors have the same length, 41 (the number of strata), and 122 is th...

Hello, I'm running R 2.10.1 on Windows Vista. I'm selecting a random sample of several hundred items out of a larger population of several thousand. I realize there is srswor() in package sampling for exactly this purpose, but as far as I can tell it uses the native PRNG which may or may not be random enough. Instead I used the random package which pulls random numbers from random.org, although in my extended reading [vignette("random-intro", package="ra...

...2 17 ST S 6 0 #THEN I attempted to use sampling::strata using the instructions in that package and got an error #I use stratum_cp$stratp for my sizes. > s<-strata(CURRPOP,c("APPT_TYP_CD_LL","EMPL_TYPE"),size=stratum_cp$stratp,method="srswor") Error in data.frame(..., check.names = FALSE) : arguments imply differing number of rows: 0, 1 > traceback() 5: stop("arguments imply differing number of rows: ", paste(unique(nrows), collapse = ", ")) 4: data.frame(..., check.names = FALSE) 3: cbind(de...

Hallo, I'm trying to sample a matrix with simple random sampling without replacement but seem to have a problem with the matrix length. Both sample() and srswor() use length() which returns the number of columns in matrix. This means that to function it seems that the sample size exceeds the matrix length. I need to sample the whole matrix for there are auxiliary variables I need for further sample processing. Ay help is much appreciated. Regards, Katja L...

...led results. We have a looping structure (also below) but we do not know how to save the coefficients and R2 values. We are missing some code (indicated) Any assistance would be greatly appreciated. Thanks, library(sampling) mall<-read.csv("mall.csv") for (j in 1:1000) { s<-srswor(2840,3550) mall80<-mall[s==1,] mall20<-mall[s==0,] model1<-lm(count~habitat,data=mall80) summary(model1) mall20$predicted<-predict(model1,newdata=mall20) model2<-lm(count~predicted,data=mall20) MISSING CODE: SAVE MODEL COEFFICIENTS AND R2 VALUE TO A DATAFRAME CALLED RESULTS }