setColNameGLPK.
Here, j can be an integer vector, cnames can be a character
vector.setColsNamesGLPK(lp, j, cnames = NULL)"glpkPtr " as returned by
initProbGLPK. This is basically a pointer to a GLPK problem
object.j or NULL.setColsNames which calls the GLPK
function glp_set_col_name. If cnames is set to NULL, all column names for column indices in
j will be removed. If cname[k] is the empty string "",
column name j[k] will be removed.