Importing Spatial Data

Importing Generic Spatial Data

SAS/GIS software provides facilities for creating spatial databases from SAS data sets that contains the following types of generic spatial data:

point (GENPOINT): consists of discrete points.
line (GENLINE): consists of discrete line segments.
polygon (GENPOLY): consists of areas that are enclosed by polylines.

You can use the generic import methods if your data is in a format other than the specific import types that were discussed earlier. The generic import methods are useful for combining map features with an existing map. However, when adding generic data to existing spatial data sets, you must ensure that coordinate systems match.

Importing Generic Point (GENPOINT) Data

To import a SAS data set that contains point data, use the GIS Spatial Data Importing window to complete the following steps:

Select Genpoint from the Import Type drop-down menu.

The title of the filename field in the Input area changes to SAS/GIS Generic Point data set.

Specify the desired SAS data set, either by typing the location in the data set field or by clicking the arrow to display the Select a Member window and then selecting the data set from that window.

The point data set must contain at least the following variables:

east-west coordinate of the point.

north-south coordinate of the point.

identifier value for the point.

Note: Each observation in the data set must have a unique value for the ID variable. [cautionend]

The data set can also contain other variables, for example, variables to define characteristics of the points.

Select the variable from the ID Vars field that you want to use as an ID variable. SAS/GIS software performs a frequency analysis on the values of the specified variable in the point data set and creates a point layer for each unique value of the specified variable. If you specify more than 16 layers, only the first 16 are added to the map. If you do not specify a layer variable, the resulting map will have a single point layer with the same name as the original point data set.
Modify the destination information for the catalog and the spatial data sets, if needed.
Modify the default layers and composites, if needed. See Defining Composites in Imported Data and Defining Layers in Imported Data for more information.
Click Import to import the data. When the import process is complete, a message is displayed in the window message bar to indicate whether the import was successful. You can proceed with another import or close the window to display the newly imported map.

Importing Generic Line (GENLINE) Data

To import a SAS data set that contains line data, use the GIS Spatial Data Importing window to complete the following steps:

Select Genline from the Import Type drop-down menu.

The title of the filename field in the Input area changes to SAS/GIS Generic Line data set.

Specify the desired SAS data set, either by typing the location in the data set field, or by clicking the arrow to display the Select a Member window and then selecting the data set from that window.

The line data set must contain at least the following variables:

east-west coordinate of a point on the line.

north-south coordinate of a point on the line.

identifier value for the line.

Note: Each line in the data set must have a unique ID value, and all observations for the points on each line must have the same value for the ID variable. [cautionend]

The data set can also contain other variables, for example, variables to define characteristics of the lines.

Select the variable from the ID Vars field that you want to use as an ID variable. SAS/GIS software performs a frequency analysis on the values of the specified variable and creates a line layer for each unique value of the specified variable. If more than 16 layers are created, only the first 16 are added to the map by default. If you do not specify a layer variable, the resulting map will have a single line layer with the same name as the original line data set.
Modify the destination information for the catalog and the spatial data sets, if needed.
Modify the default layers and composites, if needed. See Defining Composites in Imported Data and Defining Layers in Imported Data for more information.
Click Import to import the data. When the import process is complete, a message is displayed in the window message bar to indicate whether the import was successful. You can proceed with another import or close the window to display the newly imported map.

Importing Generic Polygon (GENPOLY) Data

To import a SAS data set that contains polygon data, use the GIS Spatial Data Importing window to complete the following steps:

Select Genpoly from the Import Type drop-down menu.

The title of the filename field in the Input area changes to SAS/GIS Generic Polygon data set.

Specify the desired SAS data set, either by typing the location in the data set field, or by clicking the arrow to display the Select a Member window and then selecting the data set from that window.

The polygon data set must contain at least the following variables:

east-west coordinate of a point on the polygon boundary.

north-south coordinate of a point on the polygon boundary.

ID-name(s)

identifier value(s) for the polygonal area.

Note: Each polygonal area in the data set should have unique identifier values, and all observations for the points in each area should have the same identifier value. A polygonal area can consist of more than one polygon. In that case the data set should also contain a SEGMENT variable to distinguish the individual polygons. [cautionend]

Any other variables in the data set will not be included in the spatial database.

Select the variables from the ID Vars field that you want to use as ID variables. ID variables are variables whose values uniquely identify unit areas in the map. A separate layer is created for each ID variable. The ID variables must be selected in hierarchical order. For example, if the data set contains both STATE and COUNTY variables, then STATE must be selected before COUNTY.
Modify the destination information for the catalog and the spatial data sets, if needed.
Modify the default layers and composites, if needed. See Defining Composites in Imported Data and Defining Layers in Imported Data for more information.
Click Import to import the data. When the import process is complete, a message is displayed in the window message bar to indicate whether the import was successful. You can proceed with another import or close the window to display the newly imported map.

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