Hello, I have a matrix results with dimension 1x9 double matrix XLB XLE XLF XLI 1 53.3089 55.77923 37.64458 83.08646 I'm trying to order this matrix > print(order(results)) [1] 3 1 2 4 how can the function order return the columnname XLF XLB XLE XLI instead of 3 1 2 4 any idea ? Thank you in advance --