granulo is a data frame of 29 observations and 21 variables. The first column corresponds to the apertures sizes of AFNOR sieves, in micrometer (25000, 20000, 16000, 12500, 10000, 8000, 6300, 5000, 4000, 2500, 2000, 1600, 1250, 1000, 800, 630, 500, 400, 315, 250, 200, 160, 125, 100, 80, 63, 50, 40, 0).
Warning ! the last sieve 0 corresponds to the material retained in the < 40 micrometer pan after sieving.
The others columns corresponds to the weight of samples beside each size class