search for: dista

Hi, I'm trying to do a non-metric multidimensional scaling using isoMDS. However, I have some '0' distances in my data, and I'm not sure how to deal with them. I'd rather not drop rows from the original data, as I am comparing several datasets (morphology and molecular data) for the same individuals, and it's interesting to see how much morphological variation can be associated with a...

Dear all, this might be not only an R-question but also a statistical. When I do a logistic regression analysis (species distribution modeling) with function lrm (Design package) I get the follwoing error message: > tadl1<-lrm(triad~fd+dista+fd2+dista2+fd:dista+dista:geo2, x=T, y=T) Error in if (!length(fname) || !any(fname == zname)) { : missing value where TRUE/FALSE needed The problem seems to be that geo2 (factor variable with 3 levels) is not included as main effect. But when I run the same model with glm it is working pro...

...780 1.958191 [9,] 504 848 1.997111............... ................................................................................ so you get the idea. I want to group similar items in one group/cluster following the "friends of friends" approach. I tried doing distclust <- hclust(distA,method="single") However, I got the following error. Error in if (n < 2) stop("must have n >= 2 objects to cluster") : argument is of length zero which probably means there's something wrong with my input here. Is there another way of doing this kind of clustering wi...

Hi the list, I need to include some C code in R, but the behavior of the C code is strange : Here is my code : --- 8< --- Rprintf("\n XXXX mTraj=%f mClus=%f",mTraj[i+nbId*c],mClustersCenter[j+nbClusters*c]); Rprintf("\nDistA=%d Tmp=%d",dist,tmp); tmp = mTraj[i+nbId* c] - mClustersCenter [j+nbClusters* c]; Rprintf("\nDistB=%d Tmp=%d",dist,tmp); dist += (tmp * tmp); Rprintf("\nDistC=%d Tmp=%d",dist,tmp); --- 8< ---- Herer are the stranges results it gives :...

...ary 9th and my program (attention: beginner). Thanks for both answers! a. However, as far as I know the cosine is not the same as the Pearson correlation (only in special cases). b. Reid Huntsinger's hint was very useful, however I had to transpose the matrix first, for I want to calculate the distance of the _rows_. Regards, Petra Steiner #Funktion: Berechnung der Distanzmatrix mit dem Kosinus als Abstandsmass library(Matrix) normalize <- function(ma) { # zunaechst werden die Zeilen der Matrix normalisiert nreihe <- nrow(ma) nspalte <- ncol(ma) print(nspalte) c &lt...

...orks/R.framework/Resources/include" -DNDEBUG -I../inst/include -I'/Library/Frameworks/R.framework/Versions/4.2/Resources/library/Rcpp/include' -I'/Library/Frameworks/R.framework/Versions/4.2/Resources/library/RcppArmadillo/include' -I/usr/local/include -fPIC -Wall -g -O2 -c dista.cpp -o dista.o In file included from dista.cpp:3: In file included from /Library/Frameworks/R.framework/Versions/4.2/Resources/library/RcppArmadillo/include/RcppArmadillo.h:29: In file included from /Library/Frameworks/R.framework/Versions/4.2/Resources/library/RcppArmadillo/include/RcppArmadill...