search for: ccatj

Displaying 10 results from an estimated 10 matches for "ccatj".

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2006 Feb 19
2
standardizing data
Hello R team, I??m looking for a way to standardize (z transformation= standard deviation 1 and mean 0) a row of x y coordinates in order to conduct a trend analysis. Does anyone know the command in R? many thanks for help in advance Christian
2006 Aug 31
2
need help with an interaction term
Hello! I?m fitting a model with glm(family binomial). The best model counts 9 Variables and includes an interaction term that was generated by the product of to continuous variables (a*b). All variables are correlated under a value of 0.7 (Spearman rank order) While the estimates of both main effects are negativ, the resulting interaction term is positiv. This change of sign makes it difficult to
2006 Feb 24
1
predicting glm on a new dataset
Hello together, I would like to predict my fitted values on a new dataset. The original dataset consists of the variable a and b (data.frame(a,b)). The dataset for prediction consists of the same variables, but variable b has a constant value (x) added towards it (data.frame (a,b+x). The prediction command returns the identical set of predicted values as for the original dataset yet I would have
2006 Jun 25
0
hier.part function???
Hello R-team I´ve got a question concerning the hierarchical partitioning function. If the variables of a model fitted with glm (binomial)show a high joint effect, does this necessarily only mean, that these variables are highly correlated and therefor the model fitting was not optimal, or can it also be, that a high joint contribution means, that the relevant variables only show there full
2006 Aug 30
0
fitting an interaction term
Hello! I?m fitting a model with glm(family binomial). The best model counts 9 Variables and includes an interaction term that was generated by the product of to continuous variables (a*b). All variables are correlated under a value of 0.7 (Spearman rank order) While the estimates of both main effects are negativ, the resulting interaction term is positiv. This change of sign makes it difficult to
2005 Oct 15
1
generating response curves
Hello does anyone know how to visualize a response curve based on a regression model with lines rather than dots. Having a large number of parameters the following formula is to time consuming. Perhaps a built in function exists to speed up the process. Model1<-a~b #Setting the scale extent min(area) max(area) avals<-seq(0,10,.1) # generating the plot plot(area,incidence, las=1)
2005 Oct 20
1
having scaling problems with a histogram
Hello,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p> I would like to create a histogram from a data collumn consisting of 4 classes (0; 0.05;0.5;25;75). Due to the difference in scale the classes 0;0.05 and 0.5 are displayed within one combined bin by default with the code:Hist(x, scale="percent",
2006 Jan 19
0
aggregating variables with pca
hello R_team having perfomed a PCA on my fitted model with the function: data<- na.omit(dataset) data.pca<-prcomp(data,scale =TRUE), I´ve decided to aggregate two variables that are highly correlated. My first question is: How can I combine the two variables into one new predictor? and secondly: How can I predict with the newly created variable in a new dataset? Guess I need the
2006 Jan 25
1
combining variables with PCA
hello R_team having perfomed a PCA on my fitted model with the function: data<- na.omit(dataset) data.pca<-prcomp(data,scale =TRUE), I´ve decided to aggregate two variables that are highly correlated. My first question is: How can I combine the two variables into one new predictor? and secondly: How can I predict with the newly created variable in a new dataset? Guess I need the
2005 Oct 08
2
keeping interaction terms
Hello,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p> while doing my thesis in habitat modelling I´ve come across a problem with interaction terms. My question concerns the usage of interaction terms for linear regression modelling with R. If an interaction-term (predictor) is chosen for a multiple model, then, according to