[R] R/3.1.3 source installation

R 3.1.3 is available for installation via source-code. However ./configure terminates with checking for dummy main to link with Fortran 77 libraries... none checking for Fortran 77 name-mangling scheme... unknown configure: WARNING: unknown Fortran name-mangling scheme checking whether gfor

[R] t-test: many changing groups.

I'd like to perform a t-test between groups 'A' and 'B'. The difficulty is that although there is only one response variable, there are many observations, and the grouping (A or B) differs with each observation. My code for generating the input data is shown below. I'd like to know how to approa