Snap Line Example
Snap Line Example
If you have run a free ends query
first, the target lines for snapping will be shown.
Inappropriate (too large) value for the snap tolerance may produce corrupt
results. Backup your input data first.
Set
table1 to streets
Free Ends operator
Clear MBR filter
references as snap will process a complete table only.
Set the within
distance tolerance to a suitable value. This value should be chosen
with reference to the data source (scale of source data or original map
sheet and the method of acquisition - scanned or digitised) and to the current
table precision. The available precision of the table is displayed. The
tolerance should be greater than this value.
Set the Snap update operator.
Run the
query.
Lines are snapped to nearest lines within specified tolerance. If the split
option has been set in preferences, the target line is split. A disaggregate
process is run as the final step to break lines at intersect
points. The number of snapped lines and split lines are reported.
The map window indicates snapped/split lines as shown: 
[The example shown was run on a PII, 333 Mhz. Data: 5200 urban street lines and polylines. Elapsed time of 27 minutes.]
The
revert button will restore the table to its saved
status.
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