search for: psamp

Displaying 3 results from an estimated 3 matches for "psamp".

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2011 Dec 06
2
Why can't I figure this out? :S
...arently need to be able to find and isolate influencial observations. Problem, I have no idea what the error means and where it may be from in the code. error I get is below the code { ## OLS results NameC<- lm(gpanew~female+female:lastinit+agenew+canadian+mom_ed+yearstudy) ## default: choose psamp = quantile n <- length(residuals(NameC)) k <- length(coef(NameC)) if(is.null(quantile)) quantile <- c(floor((n + k + 1)/2), floor((n + k)/2)) quantile <- rep(quantile, length.out = 2) if(is.null(psamp)) psamp <- quantile[1] ## LTS results with robust residuals NameC_lts <- lqs(gp...
2003 Jul 30
2
robust regression
...uot;contr.sum"))) Error: lqs failed: all the samples were singular Robust regression with M-estimators works (also regular least square fits, of course): rlm.formula(formula = obs ~ y + s - 1, method = "M", contrasts = list(s = ("contr.sum"))) I tried an exact sampling (psamp="exact"), but I keep getting syntax errors. Any idea how I can make the first one work? Thanks, joerg -- ---------------------------------------------------------- J?rg Schaber Instituto Cavanilles de Biodiversidad y Biologia Evolutiva Universidad de Valencia Tel.: ++34...
2005 Oct 06
0
a question about LMS and what constitutes outliers
...ich the original Rousseeuw et al. program points out that observations 1,2,3,4 and 21 are outliers. This conslusion is arrived at by testing whether the residual is greater than 2.5 * standard error Netx I ran lqs as: m <- lqs(stackloss[,-4], stackloss[,4], method='lms', control=list (psamp=4, nsamp='exact', adjust=TRUE)) (I ran it exhaustively since that was how I ran the original program from Rousseeuw) The coefficients obtained from lqs() are more or less identical to that obtained by the original program. However the scale estimates do not match. I assume that this would...