search for: qn1

Hello: I am new on R, this is the first time I work with it, I am trying to run some R example to get learn of them, but, I have a problem when running the example below: http://stat.ethz.ch/R-manual/R-patched/library/datasets/html/zCO2.html CO2.Qn1 <- CO2[CO2$Plant == "Qn1", ] SSasympOff(CO2.Qn1$conc, 32, -4, 43) # response only Asym <- 32; lrc <- -4; c0 <- 43 SSasympOff(CO2.Qn1$conc, Asym, lrc, c0) # response and gradient getInitial(uptake ~ SSasympOff(conc, Asym, lrc, c0), data = CO2.Qn1) ## Initial values are in fact...

Hello all, I have a data frame with year, month, species, fishing gear and catch (Y, M, S, F, C) and I want the sum of C by Y for species "A" and fishing gear "trawl". I tried things like aggregate(C[S=="A" & F=="trawl"], list (Year = Y[S=="A" & F=="trawl"]), fun=sum), but it didn't worked. To overcome this problem I did

...lme_3.1-89 Thanks, ...Tao +++++++++++++++++++++++++++++++++++++++++++++++++ > library(nlme) > fm1 <- nlsList(uptake ~ SSasympOff(conc, Asym, lrc, c0), data = CO2, start = c(Asym = 30, lrc = -4.5, c0 = 52)) > summary(fm1)$para[,,1] Estimate Std. Error t value Pr(>|t|) Qn1 38.13977 0.9911148 38.48169 1.991990e-06 Qn2 42.87169 1.0932089 39.21638 2.583953e-06 Qn3 44.22800 1.0241029 43.18706 1.809264e-07 Qc1 36.42874 1.1941594 30.50576 1.140085e-05 Qc3 40.68373 1.2480923 32.59673 1.424635e-04 Qc2 39.81950 1.0167249 39.16447 2.692304e-06 Mn3 28.48286 1.0624246 26....

Hi! Here is some output from an str command: > str(CO2) Classes ‘nfnGroupedData’, ‘nfGroupedData’, ‘groupedData’ and 'data.frame': 84 obs. of 5 variables: $ Plant : Ord.factor w/ 12 levels "Qn1"<"Qn2"<"Qn3"<..: 1 1 1 1 1 1 1 2 2 2 ... $ Type : Factor w/ 2 levels "Quebec","Mississippi": 1 1 1 1 1 1 1 1 1 1 ... $ Treatment: Factor w/ 2 levels "nonchilled","chilled": 1 1 1 1 1 1 1 1 1 1 ... $ conc : num 95...

Hi, I'm very new to R and absolutely love it. Does anyone know how to use something in R that functions like a BY command in SAS? For example, let's say you have a variable x, and you want to see the mean. Easy... > mean(x) But what if you want to see the mean of x conditional on another discrete variable? My best attempts so far are something like... > mean(x, y_cat=1)