search for: joosen

Hi, this should be an easy one, but I can't figure it out. I have a vector of tests, with their units between brackets (if they have units). eg tests <- c("pH", "Assay (%)", "Impurity A(%)", "content (mg/ml)") Now I would like to hava a function where I use a test as input, and which returns the units like: f <- function (x) sub("\\)",

...but there seems to be an error? mod <- nls(result~A:B, df, start = list (A=0, B=0)) Error in qr.qty(QR, resid) : 'qr' and 'y' must have the same number of rows Is there a way to fit this data? Thanks for your time by reading this, hopefully I will get an answer. Bart Joosen [[alternative HTML version deleted]]

Hi, I recieved an ascii file, containing following information: $$ Experiment Number: $$ Associated Data: FUNCTION 1 Scan 1 Retention Time 0.017 399.8112 184 399.8742 0 399.9372 152 .... Scan 2 Retention Time 0.021 399.8112 181 399.8742 1 399.9372 153 ..... I would like to import this data in R into a dataframe, where there is a column time, the first numbers as column names, and the

Hi, I'm trying to fit a model which has a response bias, but also a day to day bias. If I try to simulate the data, I don't get the right values with optim, and also I can't use the function to give a prediction interval. My simulated data are: DF <- as.data.frame(cbind(x=rep(1:10,2),dag=rep(1:2,each=10))) bias <- c(-0.2,0.5) DF$y <- ((DF$x-0.1) * 5)+2 +

...t it might not be possible to define a negative SELCET statement in a SQL call so now I'm looking for the smoothest way to generate a list of what I would like from my large database by first pulling all the names with a query like this "SELECT top 1 * FROM your_table" (thank you Bart Joosen for the idea) and then subtract the variables I am not allow to pull manually ending up with a 'positive' definition of what I want, something I can use in a SQL SELCT statement (see my email on this list from yesterday for more on that). When I query the database for the variable names I...

...e to extract the dates, but couple the ID's to the right dates, eg: ID Dates 1 16-07-01 1 06-10-95 2 24-01-02 2 .... I have no clue about how to get started, looks something for the regexp/grep/... kind of functions, but I don't get the point. Any thoughts?? Kind regards Bart Joosen PS: for the reconstruction of the dataframe: dat <- structure(list(ID = c(1, 2, 3), Dates = structure(c(2L, 4L, 6L ), .Label = c("16-01-02 16-08-94", "16-07-01 06-10-95", "24-01-02 06-10-95", "24/01/02 06-10-95", "16/01/02 16/08/94&quot...

Hi, I have to search in an online db for registered manufacturers of raw materials. Can I use R for the following: I have a list with monograph numbers eg: l <- c(198, 731,355) Now I want to make a dataframe, containing the monograph number and the information listed under COS: Certificate holder, certificate number, Status, Type Is this possible with R? kind regards Bart -- View this

Hi, I'm a database admin for a database which manage chromatographic results of products during stability studies. I use R for the reporting of the results in MS Word through R2wd. But now I think I need your help: suppose we have the following data frame: ID rrt Mnd Result 1 0.45 0 0.10 1 0.48 0 0.30 1 1.24 0 0.50 2 0.45 3 0.20 2 0.48 3 0.60 2 1.22 3 0.40 3

Hi, I'm currently doing some analyses on time of failure of a product. I found on the internet some article about the Arrhenius equation, and I can calculate the results with R. Equation: k=A*exp(-Ea/R*T) I can fit a model with lm for this purpose, so far no problem. But for the confidence interval, how can I use the Weibull distribution? Or should I use the weibull distribution at all? Or

Hi, Maybe this is more a programming questions than a specific R-project question, but maybe there is someone who can point me in the right direction. I have a picture of cirkels which I took with a digital camera. Now I want to use the diameter of the cirkels on the picture for analysis in R. I can use pixmap to import the picture, but how do I find the outside cirkels and calculate the

Hi, I have an integer which is extracted from a dataframe, which is sorted by another column of the dataframe. Now I would like to remove some elements of the integer, which are near to others by their value. For example: integer: c(1,20,2,21) should be c(1,20). I tried to write a function, but for some reason, somethings won't work x <- 1:20 near <- function(x,th) { nr <-

Hi, I have constructed a dataframe as follows: Oil <- rep(c("Oil1","Oil2","Oil3"),8) Comp <- rep(rep(c("C1","C2"),c(4,4)),3) Mth <- rep(c("M1","M1","M2","M2"),6) Meas <- rep(c(1,2),12) Result <- rnorm(24,mean=100, sd=5) df <- data.frame(Oil, Comp, Mth, Meas, Result) The same compound

Hi, I want to use Maximum likelihood to estimate the parameters from my regression line. I have purchased the book "Applied linear statistical models" from Neter, Kutner, nachtsheim & Wasserman, and in one of the first chapters, they use maximum likelihood to estimate the parameters. Now I want to tried it for my self, but couldn't find the right function. In the book, they give

Hello, Is there anyone porting R data to VisIt (http://www.llnl.gov/visit/)? Altough VisIt accepts 5 dozen of data formats, I can't get my data into VisIt. I currently ran a simulation which gave me a data frame, which I wanted to import into VisIt to further explore the dataframe. Let's say I have a data frame as follows: dat <- data.frame(cbind( 1, 1:10),X3=

Hi All, recently I used Design Expert for some Design Of Experiment work. I was happy with the interface to select which effects I want to see in my experiment, and which not. For example: I can select of course my main effects, but also if I want to see interaction A:B, B:C, A:B:C,but not A:C. This was very interessting as you can end up with fewer runs, especially in cases of 10 factors with

Hi, I want to make a data frame which contains the positions of some searched values in another data frame. Like: Dataframe 1: 1 2 3 4 1 2 3 4 2 3 4 1 2 3 4 2 4 1 2 3 2 3 4 1 Let's say I searched on "4", then Dataframe 2 should contain: x y 1 4 1 8 2 3 2 7 3 1 3 7 I have written a routine, but it seems to me that it isn't that perfect: x<- 0

Hi, I have a function of the second grade, with 2 parameters: y~A^2 + A + B^2 + B The response y is a measurement for the precision of the analytical method, where A en B are method parameters. As its neccesary to keep the precision of the analytical methad as good as possible, its usefull to optimize A en B to keep y as low as possible. But how can I do this with R? I have searched the

Hi, I tried on this, but couldn't figure it out: Suppose I have a dataframe as follows: dat <- data.frame(Day=rep(rep(c(1,2), each=4),2), Animal = rep(c(1,2), each=8), Count=c(rnorm(8, 100), rnorm(8,90))) 2 animals are being examined on 2 different days. Count is the result. Now I need to point out whether or not there is a difference between the days. I did this by an ANOVA test, while

I am attempting to sample 10 markers from each chr, with a maximum distance of 14, calculated by the location of the marker in each chromosome as loc[i+1] - loc[i]. I presume the easiest way to do this is with a while loop, so that the function keeps resampling when the max distains is greater than 14. Example code is below. I have gon as far as to select markers and calculate the distances, A

I have a data set like the following: subject visit x1 1 1 0.5 1 2 1.2 1 3 0.7 2 1 0.4 2 2 0.6 2 3 1.0 ..... where x1 is the interval between the two visits. Now I want to calculate the cumulative intervals since the beinging, for example subject visit x1 cum 1 1 0.5 0.5 1 2 1.2 0.5+1.2 1 3 0.7 0.5+1.2+0.7 2 1 0.4 0.4 2 2 0.6 0.4+0.6 2 3 1.0 0.4+0.6+1.0 ..... is there an easy to generate the