The turn-by-turn
travel instructions from MapQuest could be called an algorithm for getting from one place to another.
EXAMPLE??”DESIGNING A STAIRCASE
You may be surprised, as we were, to know that every staircase must be custom-designed to fit the circumstances
of total elevation (total ???rise???) and total horizontal extent (total ???run???). Figure 2-1 shows these dimensions.
If you search the web, you can find algorithms??”methods??”for designing staircases.
To make stairs fit a person??™s natural gait, the relationship of each step??™s rise (lift height) to its run (horizontal
distance) should be consistent with a formula. Some say the following formula should be satisfied:
(rise * 2) + run = 25 to 27 inches
Others say the following simpler formula works well:
rise + run = 17 to 18 inches
Many say the ideal rise for each step is 7 in, but some say outdoor steps should be 6 in high because people
are more likely to be carrying heavy burdens outside. In either case, for any particular situation, the total rise of
the staircase will probably not be an even multiple of 6 or 7 in. Therefore, the rise of each step must be altered
to create a whole number of steps.
These rules lead to a procedure for designing a staircase.
Pages:
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48