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0 I am running a CART decision tree on a training set which I've tokenized using quanteda for a routine text analysis task. The resulting DFM from tokenizing was turned into a dataframe and appended with the class attribute I am predicting for. Like many DFMs, the table is very wide (33k columns), but only contains about 5,500 rows of documents. Calling rpart on my training set returns a stack overflow error. If it matters, to help increase the speed of calculations, I am using the doSNOW library so I can run the model on 3 out of 4 of my cores in parallel. I've looked at this answer but can't figure out how to do the equivalent on my mac workstation to see if the same solution would work for me. There is a chance that even if I increase the ppsize of RStudio, I may still run into this error. So my qu

0 my lecturer wrote a solution for our exam, and he wrote the eigenvalue formula as $|lambda I-A |$ instead of $|A-lambda I|$ . What I understand is we use the latter to get the eigenvalue of a matrix. Is this a typo or it doesn't matter whether it's $|A-lambda I|$ or $|lambda I-A |$ ? Thanks matrices eigenvalues-eigenvectors share | cite | improve this question asked Nov 29 at 22:38 JIM BOY 35 6 2