It may take a time to convert plot one by one between global and local coordinates and back, especially in inventory projects with multiple number of inventory plots. The functions ConvertCoordinatesFromGlobalToLocal and ConvertCoordinatesFromLocalToGlobal allowes to convert multiple number of plots in batch. The following example expect the name of your root layer “Plots” and defined […]
Execution of the Field-Map scripts can be aborted by the Exit and Abort commands.
The Exit command stops execution of current script without further consequences for Field-Map operation. If Exit is being used in the script then the rest of the script after Exit command is skipped. Following simplified example demonstrates Exit command:
Log window is available for informing user about progress of execution of data processing task. Following methods are available for Log dialog: procedure OpenLog(const Caption : string); procedure MakeLogWindowStayOnTop; procedure CloseLog; procedure CloseLogWithDelay(const Delay_ms :integer); procedure HideLog; procedure ShowLog; function IsLogOpen : Boolean; procedure Log(const str : string); procedure LogExt(const str : string; appendNewLine : […]
In many tasks of data analysis the results are presented by species. However, often the data are not distributed evenly by individual species. Field-Map provides with handy solution for efficient classification of species into species groups. Class TSpeciesGroupsWrapper is available with all required functionality: TSpeciesGroupsWrapper = class(TObjectWrapper) public constructor Create; destructor Destroy; […]
Distribution charts are often useful in data analysis. Field-Map provides with the functionality for such purpose: procedure ShowDistributionChart( TableOrLayer :TObjectWrapper; const AttributeName_ :string; const NullAsZero_ :Boolean; const ClassDef_ :variant; const Xlabel_,ChartLabel_,Options_ :string); Data come from project layer or table (e.g. query result). NullAsZero parameter specifies whether missing values are assumed to […]
For parameterization of various regression models Field-Map provides with special function: ParameterizeRegressionModel…
Relational database management system (RDBMS) which is used for data storage if Field-Map supports SQL queries as a basic tool for querying and manipulating data. This is common for all RDBMS supported by Field-Map: FireBird, MSSQL, Access with minor differences in SQL syntax in each of them.
In course of Field-Map Pascal script execution various errors may appear. Such numerical, file or other errors raise exceptions which breaks script execution. Exceptions can be handled by Field-Map Pascal script in order to keep script execution under full control.
For handling exception the try..except and try..finally constructs are available.
Data in the Field-Map project are organized in layers arranged into relational database. Data table of each layer has number of various attributes (columns) and records (rows). Layers and attributes and accessed by names, records are accessed sequentially when passing-scanning through the table or by locating record by specific values of any attribute (excluding BLOB and MEMO attributes).
OnChange script on Trees.DBH_mm calculates tree basal area.
Whenever the value of DBH_mm is changed the value of BasalArea_m2 is automatically calculated.