Structures for Storing Geographic Data - Introducing Geographic Information Systems with ArcGIS - page 264

is only one part to the line a zero here indicates that. (Subsequent parts would be numbered 1, 2, and so
on.) The third text line consists of five numbers, which specify the first vertex:
the vertex ID (which starts at 0 and increases by 1 for each line)
the x-coordinate of the vertex
the y-coordinate of the vertex
the z-coordinate (in our case it will be zero)
the m-coordinate (in our case it will be zero)
Subsequent text lines are of this format until the line is completely specified. Then a second geometric
line is begun with.
<line_id> <part_number>
and the vertices of that line are specified. Study the symbolic format above until you understand this
format. (The z-coordinate relates to the vertical height if there is one. The m-coordinate relates to the
distance the vertex from the line's beginning to the vertex. (The m-coordinates will be discussed in
Chapter 9 when we take up linear referencing.)
Once all geometric lines are specified the word “END” constitutes the last text line of the file.
2. Compare the defining format above with an actual text file below. What are the x- and
y-coordinates of the second vertex of the line with the ID of 103? _____________,
_____________ This text file will be used with the Create Features From Text File tool to
create a feature class.
Polyline
101 0
0 8303.0 7100.0 0.0 0.0
1 8300.0 7100.0 0.0 0.0
2 8300.0 7106.0 0.0 0.0
3 8303.0 7106.0 0.0 0.0
4 8303.0 7100.0 0.0 0.0
102 0
0 8303.0 7100.0 0.0 0.0
1 8309.0 7100.0 0.0 0.0
2 8309.0 7106.0 0.0 0.0
3 8303.0 7106.0 0.0 0.0
4 8303.0 7100.0 0.0 0.0
103 0
0 8304.0 7101.0 0.0 0.0
1 8308.0 7101.0 0.0 0.0
2 8308.0 7105.0 0.0 0.0
3 8304.0 7105.0 0.0 0.0
4 8304.0 7101.0 0.0 0.0
END