[R] Problems when install ROCR

I meet lots of problem when installing the package ROCR, do you have meet such problems? 1, biocLite("ROCR") 2, biocLite("gplots") 3, biocLite("Rgraphviz") 4, sudo apt-get install graphviz oh, no, unlimited question, what's wrong with R in ROCR or gplots or et al Error : object ‘nobs’ is no

[R] Can I use lm() to fit more than one response and more than one variables in single expression

Dear All, Can I use lm() to fit more than one response in single expression. e.g data is a matrix of these variables R1 R2 R3 X1 X2 X3 1 2 1 1 2 3 Now i wnat to fit R1~X1 R2~X2 R3~X3 in turn, and I don't want to do it use loops of couse it it easy to make it using loops,but the proceed is