How Generate (Coverage) works

Generate creates coverages from raw coordinates stored in a text file. Any coordinate data can be loaded as long as the coordinates are put into the appropriate Generate format. For example, to generate lines, create a text file that has a User-ID number for each line, followed by the series of x,y coordinate pairs that define the line. The exact formats for these files are described for each feature type.

Annotations

Adds annotations to the coverage.

The format for annotation coordinates is:

<ID> <X> <Y> <angle> <size> <text...> 
end

An example of annotation coordinate format:

1 2 1 90 .3 This is annotation 1 
2 3 4 -90 .3 This is annotation 2 
end
Generate annotation example

Circles

Generates circles, each with a specified center and radius.

The format for circle coordinates is:

<ID> <X> <Y> <radius>
end

An example of circle coordinate format:

201, 3, 7, 2.0
202, 9, 4, 3.0
end
Generate circles example

Curves

Generates curves from three points: the starting point, the center point, and the ending point.

The format for curve coordinates is:

<ID> <start_point> <center_point> <end_point>
end

An example of curve coordinate format:

301, 1,0 2,2 5,3
end
Generate curves example

Fishnet

Creates a fishnet of rectangular cells. Nodes are created at intersection points of each cell. The following coordinate file format defines fishnet output:

If zero is specified for the cell size, then it will be automatically computed based on the next two lines in the coordinate file: the numbers of rows and columns and the opposite corner of the fishnet.

If the cell size has a value greater than zero and if the line for the number of rows and columns equals zero, then the next line in the coordinate file specifies the opposite corner of the fishnet. The specified cell size will be used to automatically calculate how many rows and columns can fit within the area defined by the origin and the upper-right corner without exceeding the corner coordinates.

The following chart describe the coordinate format for different cell size values.

Cell Size

Cell Size = 0

0,1 - fishnet origin coordinate (X,Y)

0,0 - Fishnet origin coordinate (X,Y)

1,1 - Y- axis coordinate (X,Y)

0,1 - Y- axis coordinate (X,Y)

4,4 - Cell size (width, height)

0 - Cell size (width,height)

4,4 - Number of (rows, columns)

4,4 - Number of (rows, columns)

4,4 - Opposite corner of fishnet (X,Y)

A chart to describe the coordinate format for different cell size values.

Examples

In this example, a fishnet with two rows and three columns is generated. The fishnet origin is (0,0); (0,2) is a point that lies on the positive y-axis of the fishnet, with a cell size of 1 (width) by 1 (height), and with two rows and three columns.

0,0 
0,2
1,1 
2,3
Generate fishnet example 1

In this example, the fishnet origin is shifted to (2,0), and (2,2) is a point that lies on the y-axis of the fishnet. The orientation of the y-axis of the fishnet could also have been defined with other points like (2,1), (2,3), (2,4), and so on.

2,0 
2,2
1,1 
2,3
Generate fishnet example 2

In this example, the fishnet origin is shifted to (3,2). Notice how the x-axis and y-axis of the fishnet change accordingly.

3,2 
3,4
1,1 
2,3
Generate fishnet example 3

In this example, the fishnet origin is kept at (0,0). However, the y-axis of the grid is rotated relative to the y-axis of the Cartesian coordinate system. (2,2) is a point that lies on the y-axis of the rotated fishnet. The rotation of the y-axis of the fishnet could also have been defined using the points (1,1), (3,3), (4,4), and so on, in place of (2,2). Any point that falls on the positive y-axis of the fishnet will work.

0,0
2,2
1.414,1.414
2,3
Generate fishnet example 4

In this example, the fishnet origin is moved to (1,2). As in the previous example, the y-axis of the fishnet is rotated 45 degrees. (3,4) defines a point on the positive y-axis of the fishnet.

1,2
3,4
1.414,1.414
2,3
Generate fishnet example 5

The following three examples show different methods to generate a 4x4 fishnet.

Specify cell size and number of rows/columns:

0,0
0,1
1,1
4,4

Specify number of rows/columns and opposite corner of fishnet. Cell size is set to zero.

0,0
0,1
0
4,4 
4,4

Specify cell size and opposite corner of fishnet. The number of r+ows/columns is set to zero.

0,0
0,1
1,1
0
4,4

Lines

Adds arcs to the coverage.

The format for line coordinates is:

<ID>
<X,Y>
end
end

An example of line coordinate format:

501 
2,8 
5,8 
5,5 
end 
502 
1,2 
4,5 
end 
end
Generate lines example

Links

Adds links to the coverage.

The format for link coordinates is:

<ID>
<X,Y>
<X,Y>
end
end

An example of link coordinate format:

3,10.5
6,10.5
3,0
4,0
end
Generate links example

A check is made to ensure that two coordinate pairs are entered for each link. Identity links can be added by specifying the same coordinates for both x,y pairs.

Points

Adds label points to the coverage.

The format for point coordinates is:

<ID> <X,Y> {Angle} {Scale}
end

Generate a simple point cover allowing the {Angle} and {Scale} parameters to default to 0 and 1:

601,3,7 
602,9,7 
603,5,4 
end
Generate points example

Generate a point cover specifying values for {Angle} and {Scale} for each point:

601,3,7,45,2.5 
602,9,7,-30,0.5
603,5,4,90,1.5 
end 

Polygons

Adds polygons and label points to the coverage.

The format for POLYGON coordinates is:

<ID> {AUTO | X,Y>}
X,Y
end
end

Generate a polygon with a specified label point:

701,7,7 
3,9 
4,5 
8,4 
9,7 
6,9 
3,9 
end 
end
Generate polygon example

In this example, the code automatically generates the polygon label point and adds the closing vertex.

701, auto
3,9 
4,5 
8,4 
9,7 
6,9 
end 
end 

Tics

Adds tics to the coverage.

The format for adding TICS coordinates is:

<ID> <X,Y>
end

Enter one tic per line by specifying the User-ID and the x,y coordinates for each tic. Use END to specify end of tic coordinates in the file. The following example adds four tics to the output coverage:

801,0,0 
802,0,10 
803,10,10
804,10,0 
end
Generate tics example
6/18/2012