Anguilla Library Computer Club
Resources
Lesson on Sorting and Speed
Spreadsheet lesson #4
sorted rows of information into order by the values
in one column, but we did not explore how the data was
actually sorted into order. There are actually
several methods (or algorithms) for sorting.
One performance attribute of a sort algorithm is whether it
is linear: as the number of sort items increases,
does the sort time increase proportionally, or does it increase
faster.
Activity: Measure Sorting Algorithms
Find the Sort Tutorial menu item and activate it.
After the shareware screen, you should see a menu. If you are on a Mono screen, press C to disable color. This lesson explores three sorting algorithms 
Bubble Sort, Binary Insertion Sort, and QuickSort 
using a Graphical Sort display. The program fills the screen
with random data points, then moves them as they are sorted, ending
up with a straight diagonal line.
Select Bubble Sort, then Graphical Sorting. Enter 100 as
the number of
values to sort and plot the result on the graph below as a B at
the intersection of 100 and the time in seconds. Now sort 250
items and 1000 items and plot those times. If any sort takes more than
60 seconds, press ESC to stop the sort and try again with a number
of items halfway between the last test and the aborted test.
Return to the main menu and repeat these measurements for the Binary
Insertion Sort (mark those results with an I) and the Recursive Quicksort (mark with a Q). Which is the Fastest? the Slowest?
For each algorithm, draw a line
connecting the measurement points. If the algorithm were
linear, you would get a straight line. Is any of them Linear?
Compare your results with other club members. Can you tell
which computer is the fastest?
Can you
deduce the logic of any of the sort algorithms
from the way Graphical Sorting forms the random dots into a
straight line? Now
explore the other menu options for each sort method: Program Code
Sorting is fascinating.
#Items
1000 

750 

500 

250 

100 
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60
Number of seconds to perform the sort