HP 39g hp 39g+ (39g & 40g)_mastering the hp 39g+_English_E_F2224-90010.pdf - Page 147

Assigning rank orders to sets of data It is occasionally handy to be able to assign rank orders to a set of data. You might be running a Quiz Competition Night, or recording times for the 100 meter sprint, but in either case it is handy to be able to sort the data into descending order and assign rankings. This is easy for small sets of data, but becomes difficult for larger sets. Let us assume a set of 20 competitors in the 100 meter sprint, with times recorded to two decimal places, and competitors numbered 1 to 20. Suppose that the results were as shown right... Competitor Time Enter the competitor numbers as column C1 and the times in column C2. I'm going to assume here that the competitor numbers also run from 1 to 20 but this may not be the case. In addition to this, put the numbers 1 to 20 into column C3 also. The can be a bit tedious to type in for lists longer than 20, so you could use the expressions MAKELIST(X,X,1,20,1) C1 and C1 C3 to shortcut the process, replacing 20 with whatever is needed. Make sure that the option is selected. The result should look like this... Now position the highlight on column C2 and press the key. In the SORT SETUP screen (shown below right) enter C1 as the Dependent column. This will have the effect of pairing columns C1 and C2 and then sorting column C2 into ascending order, rearranging column C1 to reflect the changes. When ready, press . The results of this sort are shown right. 1 12.23 2 11.47 3 11.34 4 12.87 5 12.23 6 11.30 7 10.51 8 11.34 9 11.46 10 12.34 11 12.23 12 11.50 13 12.01 14 11.97 15 12.05 16 12.87 17 12.02 18 12.52 19 11.37 20 10.75 The final column C3 has not been re-arranged. With a few alterations, it contains the rankings. Looking down the column it can be seen that there are two values of 11.34 (the 4th and 5th). Their ranking should therefore both be changed to 4. Continuing this process down the length of column 3 will produce the rankings for the whole 20 competitors. 147