search for: concentr

Hello-- I have a data for small population who took 1 drug at 3 different doses. I have the actual drug concentrations as well as predicted concentrations by my model. This is what I'm looking for: - Time vs Concentration by ID (individual plots), with each subject occupying 1 plot -- there is to be 9 plots per page (3x3) - Observed drug concentration is made up of points, and predicted drug concentratio...

...to 4 dataframes. The example is as follows. Moreover, I want to calculate ?test? value for these 4 dataframes. My question is that the ?test? values not correct and I do not know where the problem is. 2) There are 12 ?test? (y) values from 1). Then, I want to model the relationship between ?concentration? (X) and ?test? (Y) by fitting the linear regression, such lm(Y~X) and this is my target. I think that if I can catch ?test? (Y) values and ?concentration? (X) values into a dataframe, then I can carry out regression. So, how to catch all ?test? values from different dataframes? Or does any...

Hello R-help I have the following data for a standard curve concentration(nM),fluorescence 0,48.34 2,58.69 5,70.83 10,94.73 20,190.8 50,436.0 100, 957.9   (1)Is there function in R to plot a spline. (2)How can I interpolation,say 1000 point from 0nM-100nM and store this as a data frame of concentration,fluorescence (3)How can I modify the code below so that instead...

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 express the concentrations as % of the...

...n't support LCR, the list goes on and on. We want to replace this with several asterisk boxes each running one or two 4 port PRI cards. The problem is: I can plug in 20 PRI lines into the CSX (from PSTN) and have 1 come from CSX into asterisk. If 1 call comes in on each of the 20 pris, the CSX concentrates them into 1 pri into asterisk. Thus I only need a single PRI card for asterisk box. If I want to completly replace the CSX, I would need several boxes with 1 or 2 4 port cards. But that is a big waste of money when I can concentrate into less cables. Does anyone know of some piece of hardwa...

Hi, I've been modelling some data over the past few days, of my work, repeatedly challenging microbes to a certain concentration of cleaner, until the required concentration to inhibit or kill them increaces, at which point they are challenged to a slightly higher concentration each day. I'm doing ths for two different cleaners and I'm collecting the required concentration to kill them as a percentage, the c...

I have a Cisco VPN Concentrator 3000, It has the ability to auth PPTP tunnels off of a WinNT Domain controler. Well, I to use my samba3 box instead of a WinNT box. I have samba3 running off of an LDAP back end. Anyway, I setup the VPN Concentrator to auth off of the samba box, and when I test it with the test option, and i...

Hi, I am struggling to create a 2 by 2 multiple graphs in one page. I used par(mfrow=c(2,2)) to divide the screen into 4. In each screen I draw a pie chart (They are all same). For example, my data is like this Concentration value A1 69 A2 8 G1 51 G2 1 G3 68 G4 1 M 17 A1, A...

Dear All, I have a data sets as shown below A (Patient ID ), B and C are the Concentration of drug in blood on day 1 and day 4, D is the difference in conc. To do this in R I have written a code as follows, identified the number of patients who have more concentration on day 4 . Here I want to identify specifically the patient ID (is he patient 1 or 2 or 5 and 7), whose concentratio...

...'water','soda','soda') value=c(2,3,1,5,7,6) data=data.frame(food,type,value) share=c((2+3)/(2+3+1),5/6,1/6,5/(5+7+6),13/18,13/18) market_con=c(rep(0.8333333^2+0.1666667^2,3),rep(0.2777778^2+0.7222222^2,3)) data$market_con=market_con ###### My problem is how to calculate the concentration (market_con) for different 'food' (1st column). For one food, the concentration is defined as the sum of the squares of share of each type. The concentration is discussed for different foods separately. So it means for the same food, we have the same concentration. As you see in the a...

Dear all: I am a new R-user and I have 2 questions about it. 1) I need to find specific sub-dataframe, and then use specific column to calculate. For example, after splitting dataframe, I find specific the sub-dataframe, such as ?A.split [1]?. But, I don?t know how to find ?time? and ?concentration? columns of ?A.split [1]?. 2) The equation used to sub-dataframe is (time[i]-time[i-1])*(concentration[i]- concentration[i-1])*1/2. I don?t know how to calculate it. How can I find the specific column and use it to calculate ? x<-rep(c(1.2,6.8),4) y<-rep(c(1, 2),4) z&lt...

Dear all, I'm trying reproduce an example of bioassays Yielding Concentration-Mortality Data particularly control - adjustment model from book Bioassay of Entomopathogenic Microbes and Nematodes chapter 7 with R. I used glm with family=binomial and link=probit, but I do not know how to implement parameter gamma (control mortality - mortality of the untreated control in...

I have a data set which I would like to plot as a set of concentric circles. The data represent a count of the number of characteristics shared by various elements - an example would look like this: 1 100 2 75 3 50 4 25 I.e. all four sets share 25 characteristics, three of them share 50 characteristics, and so on. I would like to plot these as concentric circl...

Greetings, I cannot find solution for this problem (I was searching on web, but without success): I want to plot dose-response models for one concentration and many responses (lets say 200) and I don?t want to do it manually. So I use loop for this: for (i in mydata[,2:201]){ #first column is concentration pdf(paste("plot_",i,".pdf",sep = "")) plot(i~concentration,log='x') ht <...

Dear Rich, It depends how the data is generated. Although I am not an expert in ecology, I can explain it based on a biomedical example. Certain variables are generated geometrically (exponentially), e.g. MIC or Titer. MIC = Minimum Inhibitory Concentration for bacterial resistance Titer = dilution which still has an effect, e.g. serially diluting blood samples; Obviously, diluting the samples will generate the following concentrations: 1, 1/2, 1.4, 1/8, 1/16, ... (or the reciprocal: 1, 2, 4, 8, 16, ...) It makes no sense to compute the arithme...

I have question about log2 transformation and performing mean on log2 data. I am doing analysis for ELISA data. the OD values and the concentration values for the standards were log2 transformed before performing the lm. the OD values for samples were log2 transformed and coefficients of lm were applied to get the log2 concentration values. I then backtransformed these log2 concentrations and the trouble started. when i take the mean of l...

Hi all, Can anyone please guide me how to draw a Concentration ellipsoid for a bivariate system with a bivariate normal dist. having a VCV matrix : Sigma <- matrix(c(1,2,2,5), 2, 2) I would like to draw in using GGPLOT. Your help will be highly appreciated. Thanks, -- View this message in context: http://www.nabble.com/Concentration-ellipsoid-tp25...

Hi, Dear all, Could you please tell me how to select specified column in dataset and how to do the concentration-time profiles in R? Thank you! xiaoc [[alternative HTML version deleted]]

Hi, I'm using the ineq package to calculate some concentration measures (Gini, Herfindal, ...) and I was wondering if there's around also a function to calculate standard error on these measures. If not, is anybody aware of where I can find a reference on this point? Thanks. -- ======================================================== Angelo Secchi...

...> To: r-help@r-project.org >>>> Subject: [R] Simulation - Natrual Selection >>>> >>>> Hi, >>>> >>>> I've been modelling some data over the past few days, of my work, >>>> repeatedly challenging microbes to a certain concentration of cleaner, >>>> until the required concentration to inhibit or kill them increaces, at >>>> which point they are challenged to a slightly higher concentration each >>>> day. I'm doing ths for two different cleaners and I'm collecting the >>...