Table Maps
Data in mXrap, similar to other database systems, is managed within separate data tables. To obtain the relationship between one table and another, one table can be mapped onto another using a defined relationship. This relationship may be defined in space or by matching values (for example ID’s) in the different columns.
Foreign table will map to primary table i.e. the results of the table map will be found in the primary table.
One dimensional mapping
The three mapping options using identity keys are illustrated in the tables below.
The table map tool assesses the values of the foreign table against the values of the primary table with users able to select one of four inequalities.
The four available configurations to specify the inequality used in mapping
Primary and Foreign Tables
Foreign Table Mapped to Primary table using three of the available options
Spatial mapping
Spatial mapping allows for the mapping of one data set onto another with respect to its relative location. Examples of this are to map the data from a Block Model to the nearest minode, or to find the 5th closest sensor to every event in the database (used for system sensitivity analysis).
Primary table (red square) mapped to a secondary table (black square) returning the distance to 5th closest item.
Inputs for mapping will depend on the mode of mapping (One Dimensional Mapping or Spatial Mapping). For one dimensional mapping, the user is required to input "values" or "ids" while for spatial mapping "locations" are required. Tables and filters are always required.
For spatial mapping the distance from the foreign data point and the primary data point is calculated and provided automatically. Any other columns that the user wants to transfer to the primary table from the foreign table need to be specified by using the "Add an extra" option (Shown in orange in the figure below) These Extra columns are mapped across to the primary table with the names given in the mapping tool.
Group by
Group by will enable Table Map tool to execute the the mapping process in groups.
e.g. If events are to be mapped in different cluster groups, Group by 1 will be set to be cluster id.
Spatial table map grouped by cluster id.
Nearest Item Configuration
The maximum search distance that should be allowed can be set using the “maximum distance to search” options. Using a reasonable maximum distance will dramatically increase the speed of calculations as it will limit the number of permutations that need to be tested.
The following option is a advanced feature and will not be covered at this point. It is
- Map all the N nearest items (results generated in a new table)
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