SMS:Importing Shapefiles: Difference between revisions

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ARC/INFO or ArcView® shape files provide an easy method to import GIS data  into SMS.  Unfortunately the shape file format is extremely redundant, meaning  that points or lines that are shared by lines or polygons are multiply defined.   
ARC/INFO® or ArcView® shape files provide an easy method to import GIS data  into SMS.  Unfortunately the shape file format is extremely redundant, meaning  that points or lines that are shared by lines or polygons are multiply defined.   


Therefore, in order to convert a shape file to a SMS coverage, it may  take up to several minutes (depending on size) to build the correct line or  polygon topology.  This was very problematic in previous versions because SMS  often bogged down when reading moderately large files.  This is one of the  primary reasons that the new GIS  module has been developed and with or without a license to ArcObjects  shapefile data can now be managed better by SMS.
Therefore, in order to convert a shape file to a SMS coverage, it may  take up to several minutes (depending on size) to build the correct line or  polygon topology.  This was very problematic in previous versions because SMS  often bogged down when reading moderately large files.  This is one of the  primary reasons that the new GIS  module has been developed and with or without a license to ArcObjects® shapefile data can now be managed better by SMS.


With the addition of the GIS module there are now two different ways to  import shapefile data.   
With the addition of the GIS module there are now two different ways to  import shapefile data.   


===Direct Conversion of Shapefile Data to Coverages===
===Direct Conversion of Shapefile Data to Coverages===
The first is the traditional method which allows a user to load a shapefile  layer directly into a coverage.   
The first is the traditional method which allows loading a shapefile  layer directly into a coverage.   


A user can then map attribute fields of the shapefiles database (*.dbf) file to  their pertinent SMS parameters .
Then map attribute fields of the shapefiles database (*.dbf) file to  their pertinent SMS parameters .


===Using the GIS Module to Convert Shapefile Data to Coverages===
===Using the GIS Module to Convert Shapefile Data to Coverages===
When opening a shapefile in the GIS  module using the '''Add Shapefile  Data''' or '''Add Data''' commands SMS first reads the points/lines/polygons into a  simple display list and does not try to "build" topology by connecting arcs at  nodes, and eliminating shared edges of polygons as required when creating a  coverage.  This makes the display and selection of the polygons much easier and  more efficient.  The user can then select only the polygons that should be converted to a coverage and map them.  In this way, the model will only be building topology for the selected polygons.
When opening a shapefile in the GIS  module, using the [[SMS:GIS_Module_Menus#GIS_Data_Menu_Commands|'''Add Shapefile  Data''']] or [[SMS:GIS_Module_Menus#GIS_Data_Menu_Commands|'''Add Data''']] commands in the ''GIS Data'' menu, SMS first reads the points/lines/polygons into a  simple display list and does not try to "build" topology by connecting arcs at  nodes and eliminating shared edges of polygons as required when creating a  coverage.  This makes the display and selection of the polygons much easier and  more efficient.  Then select only the polygons that should be converted to a coverage and map them.  In this way, the model will only be building topology for the selected polygons.


===Cleaning Imported Shapefile Data===
===Cleaning Imported Shapefile Data===
If intending to use the data from the shape file in more than one session, a user should save it as a SMS map file after importing/mapping the first time.  Further, after importing the shape files, consider the  following:
If intending to use the data from the shape file in more than one session, save it as a SMS map file after importing/mapping the first time.  Further, after importing the shape files, consider the  following:
# Clean  the feature objects in order to snap nodes within a certain distance, intersect  arcs, and eliminate dangling arcs.
# Clean  the feature objects in order to snap nodes within a certain distance, intersect  arcs, and eliminate dangling arcs.
# Build  polygons so that SMS can define the appropriate conceptual model.  After  intersection of arcs, reordering of streams, etc. it is often necessary to  rebuild the polygon topology so that the topologic structure is  consistent.
# Build  polygons so that SMS can define the appropriate conceptual model.  After  intersection of arcs, reordering of streams, etc. it is often necessary to  rebuild the polygon topology so that the topologic structure is  consistent.
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[[Category:SMS GIS|I]]
[[Category:SMS GIS|Import]]
[[Category:Importing Data|I]]
[[Category:Importing Data|Shape]]
[[Category:SMS File Formats|I]]
[[Category:SMS File Formats|Import]]

Latest revision as of 19:22, 24 August 2017

ARC/INFO® or ArcView® shape files provide an easy method to import GIS data into SMS. Unfortunately the shape file format is extremely redundant, meaning that points or lines that are shared by lines or polygons are multiply defined.

Therefore, in order to convert a shape file to a SMS coverage, it may take up to several minutes (depending on size) to build the correct line or polygon topology. This was very problematic in previous versions because SMS often bogged down when reading moderately large files. This is one of the primary reasons that the new GIS module has been developed and with or without a license to ArcObjects® shapefile data can now be managed better by SMS.

With the addition of the GIS module there are now two different ways to import shapefile data.

Direct Conversion of Shapefile Data to Coverages

The first is the traditional method which allows loading a shapefile layer directly into a coverage.

Then map attribute fields of the shapefiles database (*.dbf) file to their pertinent SMS parameters .

Using the GIS Module to Convert Shapefile Data to Coverages

When opening a shapefile in the GIS module, using the Add Shapefile Data or Add Data commands in the GIS Data menu, SMS first reads the points/lines/polygons into a simple display list and does not try to "build" topology by connecting arcs at nodes and eliminating shared edges of polygons as required when creating a coverage. This makes the display and selection of the polygons much easier and more efficient. Then select only the polygons that should be converted to a coverage and map them. In this way, the model will only be building topology for the selected polygons.

Cleaning Imported Shapefile Data

If intending to use the data from the shape file in more than one session, save it as a SMS map file after importing/mapping the first time. Further, after importing the shape files, consider the following:

  1. Clean the feature objects in order to snap nodes within a certain distance, intersect arcs, and eliminate dangling arcs.
  2. Build polygons so that SMS can define the appropriate conceptual model. After intersection of arcs, reordering of streams, etc. it is often necessary to rebuild the polygon topology so that the topologic structure is consistent.

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