The Spread of AIDS
Part 1: Plotting the Data
The following table* describes
the early spread of the AIDS epidemic in the U.S. by showing the total numbers
of AIDS cases reported to the Centers for Disease Control as of the indicated
dates. These are the same data you used in Part 2 of the Functions
Defined by Data module. In this module we will carry out a complete analysis
of the data.
| Month |
Months
from
Jan 1, 1980 |
Number
of
Cases |
| Sep 1981 |
20 |
110 |
| Oct 1981 |
21 |
129 |
| Jan 1982 |
24 |
220 |
| Mar 1982 |
26 |
257 |
| Jun 1982 |
29 |
439 |
| Aug 1982 |
31 |
514 |
| Dec 1982 |
35 |
878 |
| Feb 1983 |
37 |
1,029 |
| Jun 1983 |
41 |
1,756 |
| Sep 1983 |
44 |
2,057 |
| Feb 1984 |
49 |
3,512 |
| May 1984 |
52 |
4,115 |
| Dec 1984 |
59 |
7,025 |
| Mar 1985 |
62 |
8,229 |
| Aug 1985 |
67 |
12,067 |
| Oct 1985 |
69 |
14,049 |
| Feb 1986 |
73 |
16,458 |
| Dec 1986 |
83 |
28,098 |
| Jun 1987 |
89 |
36,058 |
| Mar 1988 |
98 |
56,575 |
| Dec 1989 |
119 |
113,891 |
| Dec 1991 |
143 |
202,843 |
| Aug 1992 |
151 |
226,252 |
- You will find in
your worksheet a set of commands for plotting the list of data points.
Enter these commands now.
- Change the plot to a semilog
plot, and describe what you see. What would it mean if the data points line
up roughly along a straight line? Is that the case here? What do you conclude?
- Now
change the plot to a log-log plot, and describe what you see. What would it
mean if the data points line up roughly along a straight line? Is that the
case here? What do you conclude?
In the next part you will use your
observation about the type of growth to find a formula for the
number of cases as a function of time.
* Derived from the
Morbidity and Mortality Weekly Report
of the Centers for Disease Control.
