similar to: logistic regression or discriminant analysis ?

Perhaps, I should complement my previous e-mail question: I am trying to select variables through a quadratic discriminant analysis. It seems to me that a robust criterion is the value of the discriminatory power (i.e. the ratio of the separation of the class means to within-class variance) How can I obtain this ratio from V & R's qda() output ? Thanks (I hope this question is relevant) --

Dear all, I have written a small set of functions for drawing graphical representations of R objects and evaluations of R expressions. It is mainly intended for pedagogical purposes. Here are some samples: http://panini.u-paris10.fr/~sloiseau/sampleGraphics.pdf The idea is to use some graphical conventions in order to make clear the abstract syntax and to explain function, extraction,

Dear R user, I'm using qda (quadratic discriminant analysis) function (package MASS) to classify 58 explanatory variables (numeric type with different ranges) using a grouping variable (factor 2 levels "0" "1"). I'm using the qda method for class 'data.frame' (in this way I don't need to specify a formula). Using the function:

Hi, I'm a newbie in R and don't much aobut all the modules and their capabilities, but I'm interested in solving a problem about a discriminant analysis done with SPSS tool. The thing is that I would like to make a discrimant analysis similar to the one done with SPSS, but I can't find the way to solve it. I've been playing with R and I can handle more or less my data,

Hi, I'm a R newbie and I have a supervised 2-class classification problem. To find out the best representation of my data (dim = 45). I want to perform LDA und QDA on the diffrent data representations to find out, which is best to discriminate the 2 sets. For LDA there exists a method plot.lda shows (in the 2 class case) a histogramm of the data, projected onto the linear discriminants (pleas

Hello, I might have missed it in the help pages, but I cannot find if something exits in a package to make discriminant analysis. Any help, or hint about where to look for it, is welcome, Laurent -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help",

Dear R Help Members, I am aware how to plot the LD1 vs LD2 from a lda in R, using the code: plot(baseline.systat.hat$x, col=baseline.systat.hat$class,pch=as.numeric(baseline.systat.hat$class)) However, I need to use the quadratic discriminant function, qda due to data properties. Is there a way to obtain the same sort of plot for from a qda object (and the output of predict qda). I have not

Hi, I have been using some of the functions in r for classification purposes, chiefly lda, qda, knn and nnet. My problem is that the only one I can figure out how to represenent graphically is lda (using plot.lda). I have tried 'fooling' this function into accepting qda input for plotting but to no avail. I wonder if you have any suggestions? Thanks alot, Anne Marie Power Marine lab.

Can one perform a QDA in R? I do not see it anywhere within the mda package. Any pointers here would be appreciated. Thanks, cjf -- ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* Christopher J. Fonnesbeck Ph.D. Student Georgia Cooperative Wildlife Unit University of Georgia Athens, GA 30602 Email: cjf at fonnesbeck.net Yahoo: fonnesbeck_chris ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*

Dear colleague, I'd like to compute linear discriminant analysis, using R. In the book Modern applied statistic with Splus (Venables & Ripley, p. 396), lda function is used. Could you tell me where I can find this function? At what site, can I download this library ? Thank for your help. Best Regards Sovan ---------------------------------------------------------------- Prof. Sovan

Hello, I am switching from SPSS-Windows to R-Linux. My university is very SPSS-oriented so maybe that's the cause of my problems. I am a beginner in R and my assignments are SPSS-oriented, so I hope I don't annoy anyone with my questions... Right now I've got 2 problems: -I have to evaluate discriminant functions I have calculated with lda(MASS). I can't find a measure that

Hello, Does anyone knows how to do the plots from discriminant analysis (lda and qda)? Is there any computed function to do the stepwise procedure? thank you in advance Marta

All Is there an R command to produce error bars around a plotted point. Crawley's book uses the command error.bar() but my version of R rejects it. Must be an S+ command(?). Thanks REX [[alternative HTML version deleted]]

I'm running a four-group, 15-variable discriminant analysis using the MASS function lda(). Discriminant functions 1 and 2 explain about 93% of the variance. I would like to plot the group scatters in a single scatterplot, identify each group's centroid, and encircle the group scatter with a 90% bivariate confidence ellipse. I can do this for each group on a separate plot, but I

Hi Are there any functions that de-convolute data into a given number of clusters, rather like the NPMLE GLIM macros from Murray Aitkin and Brian Francis? Basically I would like to code into R the same approach but include the possiblility of some data being censored. In principle the formulae are the same (just replace the likelihood function) but I haven't managed to get my head round the

Hi list, I'm looking about lda function. I'd like to know how calcolate the value of the discriminant functions for the original datas. I see that in the result object "lda" there is $scaling a matrix which transforms observations to discriminant functions, normalized so that within groups covariance matrix is spherical. I'd like to have the value of the discriminant

Hi all! I am Angela, an Italian researcher and I am looking for an application that allows working in team, making a shared codebook, share a text database and code it. I tried AnSWR (the CDC''s QDA application) but its installation is too complicated for students and it is not working on latest version of Windows. What about Weft? Is it possible to share a project or, at least, merge

I have used PCA for data classification by visual examination of the 3D scatter plot of the first 3 principal components. I now want to use the results to predict the class for new data. I have used predict.princomp to predict the scores and then visualise the results on a 3D scatter plot using the rgl library. However, is there an R function that will fit the new data to the class assignments

Hi all, If I run LDA on the same data (2-class classification) with default(no priors specified in the lda function) vs. "prior=c(0.5, 0.5)", the results are different. The (0.5, 0.5) priors give better 1-classify-to-1 rate, and the proportional priors(default, no priors specified in the lda function) give better 0-classify-to-0 rate, for both training and testing data sets. However,

Hi, What does this mean when I have something like: > qda.boot <- boot(train, qda.bootstrap, R = 500) Error in qda.default(structure(data.matrix(x), class = "matrix"), ...) : Rank deficiency in group M with my qda.bootstrap() looks something like: > qda.bootstrap <- function(data, index) { + boot.qda <- qda(x = data[index, 2:9], group = data[index, 1]) + qda.pred