|
|
||||||||
|
Levels of Generalisation |
Data |
Tolerance |
No |
(%) |
Tolerance |
No |
(%) |
Figure |
|
|
|
(m) |
|
|
(sq m) |
|
|
|
|
Weeding |
|
|
|
|
|
|
|
|
|
|
Line |
0.125 |
118 |
(43) |
0.35 |
118 |
(43) |
|
|
Minimal |
|
|
|
|
|
|
|
|
|
Simplifications |
|
|
|
|
|
|
|
|
|
|
Line |
0.16 |
95 |
(35) |
1.0 |
96 |
(35) |
2a |
|
|
Line |
0.5 |
62 |
(23) |
3.6 |
62 |
(23) |
2b |
|
|
All Data |
0.5 |
384 |
(22) |
3.6 |
382 |
(22) |
|
|
|
Line |
1.0 |
45 |
(16) |
12.0 |
46 |
(16) |
2c |
|
|
All Data |
1.0 |
294 |
(16) |
9.0 |
297 |
(16) |
2d |
|
Elimination of |
|
|
|
|
|
|
|
|
|
Minor Features |
|
|
|
|
|
|
|
|
|
|
Line |
1.7 |
32 |
(11) |
45.0 |
33 |
(12) |
3a |
|
|
All Data |
3.5 |
181 |
(8.6) |
45.0 |
180 |
(8.6) |
3b |
|
Elimination of |
|
|
|
|
|
|
|
|
|
Major Features |
|
|
|
|
|
|
|
|
|
|
All Data |
5.9 |
133 |
(5.6) |
100.0 |
131 |
(5.4) |
4a |
|
|
Line |
6.0 |
16 |
(5.3) |
200.0 |
16 |
(5.3) |
4b |
|
|
Line |
|
|
|
1000.0 |
4 |
(0.8) |
4c |
|
|
Line |
100 |
5 |
(1.1) |
|
|
|
4di |
|
|
Line |
200 |
3 |
(0.4) |
|
|
|
4dii |
|
|
All Data |
50 |
68 |
(1.4) |
1000.0 |
66 |
(1.3) |
5 |
TABLE 1 : Performance of Two Filtering Algorithms at Various Levels of Generalisation
Note: There are 1610 points an the map
of which 46 points are line ends. The selected line consists of 268 points,
including the 2 end points. Percentages are of internal points only.