This tool allows the user to create, from a cadastral or thematic IL represented by entities of the type point or polygon, another thematic, cadastral or numeric IL, but with entities of type point.

Generating sampling points from a thematic IL

  • activate in the "Control Panel" a thematic category and an associated IL that contains polygons or vector points. IL's with a raster representation cannot be used, but if you wish, first convert the matrix into a vector;
  • click on Tools - Sampling Points Generation... in the main menu. The associated window will be displayed;
  • click on Output Category...to choose the category to which the output IL will belong. The window "Categories List" is presented. Choose a numeric or thematic category and click on Apply in this window;
  • type in the name of the Output Layer to be created;
  • click on Apply.

IMPORTANT: The operation is performed over the IL or Cadastral Map that is active in the "Control Panel".

NOTE: Note that the new IL should be available in the "Control Panel". If the output category is of the numeric model, the heights of the points will be the classes associated to the polygons or thematic points.

Generating sampling points from a cadastral IL

  • activate in the "Control Panel" a cadastral category and an associated IL that contains polygons or vector points
  • click on Tools - Sampling Points Generation... in the main menu. The associated window will be displayed;
  • click on Output Category...to choose the category to which the output IL will belong. The window "Categories List" is presented. Choose a numeric, thematic or cadastral category and click on Apply in this window;
  • type in the name of the Output Layer to be created;
  • in case the output category is of the model Numeric, select from the list Category the desired object and select also, from the list Attributes, that will be used as the value of the height Z of the generated point;
  • click on Apply.

NOTE: Note that the new IL should be available in the "Control Panel". If the output category is of the model numeric, the heights of the points generated correspond to the attributes of the selected object.

Generating Sampling Points: Concepts

When the input IL contains polygons you can opt to generate the points from he center of mass of the polygons or from its centroid (the point used to identify the object or class). The figure below shows an example of a cadastral map with polygons where sampling points were generated from the center of mass and also from the centroid.
Cadastral Polygons

 

, Points - center of mass

Points - centroid

 

The table below presents the possible types for the generation of sampling points. In case the input IL contains polygons you must opt to generate the points from the center of mass or the centroid.

Input

Numeric (Output)

Thematic (Output)

Cadastral (Output)


Cadastral Polygons

 

3D Points (choose the center of mass or the centroid)

Suffix (_LAB)

* the attribute of the object will be the height Z of the point.

* only labeled polygons will be converted into points.

2D Points (choose the center of mass or the centroid)

Suffix (_LAB)

* the point will not be associated to any class.

* every polygon (either labeled or not) will be converted  into points. BUG1

2D Points (choose the center of mass or the centroid)

Suffix (_LAB)

* the points created will keep the association with the object.

* only labeled polygons will be converted into points.

Cadastral Points

3D Points (the cadastral point itself will be a numeric)

Suffix (_P2D)

* the object attribute will be the height Z of the point.

* only labeled points will be converted into points.

Cannot do that

* you can use the cadastral point itself for the analysis, without the need to copy into thematic.

Cannot do that

* you can use the cadastral point itself for the analysis.

Thematic Polygons

3D Points (choose the center of mass or the centroid)

Suffix (_LAB)

* the code of the class will be the height Z of the point.

* every polygon (associated or not with a class) will be converted into points. Polygons that are not associated will have Z = 0.

2D Points (choose the center of mass or the centroid)

Suffix (_LAB)

* every polygon (associated or not with a class) will be converted into points.

Cannot do that

Cadastral categories are not presented for this option.

Thematic Points

3D Points (the cadastral point itself will be a numeric)

Suffix (_P2D)

* the code of the class will be the height Z of the point.

* every point (associated or not with a class) will be converted into points.

* points that are not associated will have Z=0 for the spot height.

Cannot do that

* you can use the thematic point itself for the analysis,  without the need to copy into another thematic.

Cannot do that.

Cadastral categories are not presented for this option.