|
|
Varying Q
| class |
AaBb |
Aabb |
aaBb |
aabb |
Total |
| observed |
310 |
287 |
288 |
315 |
1200 |
| z = Log10 |
[ |
L( ) |
] |
| L(0.5) |
L(Q) = (Q)575
(1-Q)625
Log10[L(Q)]
= 575Log10(Q)
+ 625Log10(1-Q)
| Log10[L(0.5)] |
= 575Log10(0.5) + 625Log10(0.5) |
| |
= 1200Log10(0.5) |
| |
= 1200(-0.30103) |
| |
= -361.24 |
Now we will vary Q and plot the lod score
versus Q.
Say Q = 0.1, then Log10[L(Q)]
| |
= 575Log10(0.1) + 625Log10(0.9) |
| |
= 575(-1) + 625(-0.0458) |
| |
= -546.4
|
The Lod score when Q = 0.1 = -546.4 + 361.24
= -185.16
The Lod score when Q = 0.2
| |
= 575Log10(0.2) + 625Log10(0.8) - 1200Log10(0.5) |
| |
= -101.24 |
The Lod score when Q = 0.3
| |
= 575Log10(0.3) + 625Log10(0.7) - 1200Log10(0.5) |
| |
= -36.229 |
The Lod score when Q = 0.4
| |
= 575Log10(0.4) + 625Log10(0.6) - 1200Log=10(0.5) |
| |
-6.231 |
The Lod score when Q = 0.45
| |
= 575Log10(0.45) + 625Log10(0.55) |
| |
- 1200Log10(0.5) |
| |
= -199.4028 - 162.27332 + 361.24 |
| |
= -0.43612 |
The Lod score when Q = 0.475
| |
= 575Log10(0.475) + 625Log10(0.525) |
| |
- 1200Log10(0.5) |
| |
= -185.901 - 174.90 + 361.24 |
| |
= 0.439 |
The Lod score when Q = 0.49
| |
= 575Log10(0.49) + 625Log10(0.525) |
| |
- 1200Log10(0.5) |
| |
= -178.1373 - 182.7686 + 361.24 |
| |
= 0.334
|
Now we can plot the Lod score as Q changes.
Copyright
2000©, Ted Helms |
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