similar to: lm function - strange error

Displaying 20 results from an estimated 900 matches similar to: "lm function - strange error"

2012 Nov 09
1
lm function - na.action
How do you lm throw away excess data points. I am following the documentation with no success -- View this message in context: http://r.789695.n4.nabble.com/lm-function-na-action-tp4649075.html Sent from the R help mailing list archive at Nabble.com.
2008 Aug 18
1
lmer syntax, matrix of (grouped) covariates?
I have a fairly large model: > length(Y) [1] 3051 > dim(covariates) [1] 3051 211 All of these 211 covariates need to be nested hierarchically within a grouping "class", of which there are 8. I have an accessory vector, " cov2class" that specifies the mapping between covariates and the 8 classes. Now, I understand I can break all this information up into individual
2009 Sep 10
2
patching from different directory
Howdy, I have a diff file in my /var/tmp and would like to apply patch to a file in a different directory (other than /va/tmp). I tried using patch with -d switch, but that doesn't work. It complains abt 'patch: **** Can't open patch file tilda.diff : No such file or directory'. Do I need to copy my diff file to the directory where original file resides? Or is there any other way
2010 Dec 30
2
unexpected input in rpart
Hi all, I'm a newbee using R. I need to do a classification tree using the rpart package. Basically I have a set of birds of known sex and several morphological measurements and we want to predict the sex using the morphology. I read my csv file and it shows up in R no problem, looks fine but when I execute the following rpart command
2011 Jun 28
1
Axes labels, greek letters and spaces
Hello all, I can't seem to figure how to use a greek character in expression() in plot() labels without adding a space. So for example below when plotting this out x<-1:10 plot(x,x^2, xlab=expression(Chlorophyll~italic(a)~mu~g~cm^-2)) the axis label read as μ g cm^-2 because I have space there with a tilda. But if I remove the tilda then my units are mug cm^-2. Can anyone recommend a
2007 Nov 28
1
ifelse function
Hi there, I need help with IFELSE function. The column g of my dataset pth, pth$g consists of "aa", "ao", "dcl", "iy", "sh". The last few values of pth$g looks like: [4496] sh ao ao sh iy dcl dcl aa iy iy aa sh ao ao Levels: aa ao dcl iy sh I want to convert these values into 1,2,3,4,5. I tried to use a loop and I found the following
2005 Oct 11
2
Problems with plot function
Hello all R users, My simulation function works correctly, but I have problems with plot function. You will find the following code using it. Thank you for your help ##################################################" simulation <- function(k, n){ conc <- seq(0,10,by=0.5) #choixg <- seq(1, length(conc)) choixg <- rep(0,length(conc)) for (i in 1:length(conc)){ choixg[i]
2010 Apr 26
1
finite difference scheme for 2D differential equations
Hello everyone, I am trying to solve 2D differential equations using finite difference scheme in R. I have been able to work with the equations with only one spatial dimensions but I want to extend it to the two dimensional problem. For example i can simulate one dimensional diffusion using a code like the following. But I want to write a similar code for,say, a two dimensional diffusion
2007 Jul 16
5
formula(CO2)
The formula attribute of the builtin CO2 dataset seems a bit strange: > formula(CO2) Plant ~ Type + Treatment + conc + uptake What is one supposed to do with that? Certainly its not suitable for input to lm and none of the examples in ?CO2 use the above.
2005 Oct 13
1
problems with loop and plot function
Hi all R users, I have problems with my second loop for drawing the three curves in the same graphic. I need help please Thank you in advance ######################################################################### simulation <- function(k, n){ conc <- seq(0,100,by=0.5) #choixg <- seq(1, length(conc)) choixg <- rep(0,length(conc)) for (i in 1:length(conc)){ choixg[i] <- (k
2005 Apr 19
3
Help with predict.lm
Hi I have measured the UV absorbance (abs) of 10 solutions of a substance at known concentrations (conc) and have used a linear model to plot a calibration graph with confidence limits. I now want to predict the concentration of solutions with UV absorbance results given in the new.abs data.frame, however predict.lm only appears to work for new "conc" variables not new "abs"
2023 Oct 24
2
How to Calculate the Mean by Multiple Groups in R
Hi, I think you're misunderstanding which set of variables go on either side of the formula. Is this what you're looking for? > aggregate(OD ~ Time + Target + Conc, data = df, FUN = "mean") Time Target Conc OD 1 1 BACT 1 765.3333 2 1 BACT 2 745.3333 3 1 BACT 3 675.0000 > aggregate(ODnorm ~ Time + Target + Conc, data = df, FUN =
2004 Aug 16
2
using nls to fit a four parameter logistic model
Shalini Raghavan 3M Pharmaceuticals Research Building 270-03-A-10, 3M Center St. Paul, MN 55144 E-mail: sraghavan at mmm.com Tel: 651-736-2575 Fax: 651-733-5096 ----- Forwarded by Shalini Raghavan/US-Corporate/3M/US on 08/16/2004 11:25 AM ----- Shalini
2006 Jul 18
2
Using corStruct in nlme
I am having trouble fitting correlation structures within nlme. I would like to fit corCAR1, corGaus and corExp correlation structures to my data. I either get the error "step halving reduced below minimum in pnls step" or alternatively R crashes. My dataset is similar to the CO2 example in the nlme package. The one major difference is that in my case the 'conc' steps are
2023 Oct 24
2
How to Calculate the Mean by Multiple Groups in R
Hello, I have a data frame with different groups (Time, Target, Conc) and each entry has a triplicate value of the measurements OD and ODnorm. How can I merge the triplicates into a single mean value? I tried the following: ``` df = data.frame(Time=rep(1, 9), Well=paste("A", 1:9, sep=""), OD=c(666, 815, 815, 702, 739, 795, 657, 705, 663),
2012 Aug 07
2
Passing arguments to a function within a function ...
Hallo Everybody How do you specify arguments for a function used within another function? Here is my problem: I am reconstructing a calculator for the burden of disease due to air pollution from publications and tools published by the WHO. The calculations make use of published dose-response relationships for particular health end-points. This is then applied to populations with known or
2008 Nov 11
2
strsplit (regex)
#how do I break these up into first two letters (RM), number, and then the last part #is there an easily accessible regex tutorial on the internet? v = (structure(1:122, .Label = c("RM215Temp", "RM215SpCond", "RM215DO.Conc", "RM215Depth", "RM215pH", "RM215ORP", "RM215Turbidity.", "RM215Battery", "RM215DO.",
2009 Dec 18
2
NLS-Weibull-ERROR
Hello I was trying to estimate the weibull model using nls after putting OLS values as the initial inputs to NLS. I tried multiple times but still i m getting the same error of Error in nlsModel(formula, mf, start, wts) : singular gradient matrix at initial parameter estimates. The Program is as below > vel <- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14) > df <- data.frame(conc, vel) >
2009 Sep 03
2
dividing a dataframe column by different constants
Dear R users, today I've got the following problem. Here you are a dataframe as example. There are some SAMPLES for which a CONCentration was recorded through TIME. The time during which the concentration was recorded is not always the same, 10 points for Sample A, 7 points for Sample B and 11 for sample C Also the initial concentration was not the same for the three samples. I would like
2012 Mar 27
4
Help on predict.lm
Hello, I'm new here, but will try to be as specific and complete as possible. I'm trying to use “lm“ to first estimate parameter values from a set of calibration measurements, and then later to use those estimates to calculate another set of values with “predict.lm”. First I have a calibration dataset of absorbance values measured from standard solutions with known concentration of