Feature Detection Method dialog
Feature Detection Methods
Allows you to specify how the records of the file will be grouped to create features.
Identify Features by Code (recommended)
Always select this method unless you need the Consecutive Sequence Numbers method below. If there is a code field on each record (defined in the Import ASCII Structure dialog), the code will be cross-referenced to the formatting you specify on the Code tab. If there is no code field specified then the Default code will be applied to all records. If you define a code to be a Polyline type, then records with the same code will be chained together to create multi-point features. If you define a code to be a Point type, any records with the same code will become individual single point features.
Consecutive Sequence Numbers
Set the column position of the sequence number field. The sequence number is assumed to be increasing in each record e.g. 1,2,3,.. Whenever this number decreases a new feature is assumed to start.
Consecutive Matching Codes (obsolete)
Features will be constructed from consecutive records that contain the same ID.
NOTE: this item is included for backward compatibility only. Use Identify Features by Code instead - the same behaviour can be achieved by setting Code type to Polyline and Feature Creation to Connect Adjacent.
Each Coordinate is a Feature (obsolete)
Each record corresponds to one feature. This will import all the records as points only. You can still specify a code column, and setup code formatting to place symbols at specific points on the Code tab.
NOTE: this item is included for backward compatibility only. Use Identify Features by Code instead - the same behaviour can be achieved by setting Code type to Point.
Entire File is One Feature (obsolete)
All the records in the file will be used to create one feature.
NOTE: this item is included for backward compatibility only. Use Identify Features by Code instead - the same behaviour can be achieved by setting the DEFAULT Code type to Polyline and not defining a Code item in the Import ASCII Structure dialog (set column to 0).
Sequence # (Column)
This field contains the position in the record of the feature sequence number. This field is only used if the feature detection is set to "Consecutive Sequence Numbers".
Feature Size
This allows you to limit the maximum number of points in a Polyline feature (see also the Code tab). If you have a very large number of records to read, it is most efficient to read them into Polyline features and to limit the number of points. This also makes it easier to manipulate the data after the import (for example you may wish to select and delete part of the data that is outside your area of interest).
Limit size of Features
When checked, this enables the "Max points per feature" edit box. When clear, there is no limit to the size of features created during import.
Max points per feature
Polyline Features created during import will not exceed this number of points; multiple features with the same name will be created instead (no records are discarded that would have been incorporated otherwise).
End Feature
This allows you to end a feature by including a character in the code field. The following is a file with a CL feature imported as a polyline. The feature is broken using the "!" character in the code field.
1,5469244.519,492493.09,260,CL
2,5469211.323,492513.337,263.361,CL
3,5469208.928,492510.665,263.725,CL! // end of feature 1
4,5469212.137,492514.834,263.351,CL
5,5469204.952,492507.633,263.824,CL
6,5469214.16,492516.963,262.599,CL
7,5469223.313,492506.024,262.214,CL! // end of feature 2
8,5469219.664,492498.138,262.203,CL
9,5469221.812,492502.766,262.492,CL
10,5469223.999,492507.501,261.492,CL
11,5469232.003,492503.436,261.392,CL
12,5469231.401,492499.739,261.637,CL
13,5469232.538,492504.938,260.801,CL // end of feature 3 (end of file)
This option is only available if the parsing method is Identify features by Code.
Terminate Character
Enter a character to terminate the feature. The default is "!".
