One day, my officemate Tieming asked me about a problem that she met in her research. Suppose \(\boldsymbol{B}\) is a symmetric matrix of huge dimension and \(\boldsymbol{D}\) is a diagonal matrix with nonnegative diagonal elements. The inverse of \(\boldsymbol{B}\) is already known, how can we calculate the …

R is a language that is friendly to vector operation, so vector is an important data structure in R. A single data (of basic types, e.g., numeric or character) is essentially a vector of length 1. A matrix or an array in R is essentially a vector. R make …