Matrices Exercises

These exercises cover the matrices sections of Introduction to R.

Exercise 1

• Create a matrix containing information on gene names Gene_1, Gene_2, Gene_3,Gene_4 expression values 1000, 3000, 10000, 12000 and gene lengths 100, 3000, 200, 1000

• Update the matrix to contain the expression over the gene length for all genes (Length normalised expression - LNE) as final column.

• Create a smaller matrix containing genes longer than 200

• Create a smaller matrix with just expression and LNE columns containing genes longer than 200 and expression greater than 3000

• Calculate the sum of expression and length columns for only genes with length > 100.