====== Extract Map Attributes =====

===== Description =====

This functor extracts the attributes and calculates basic statistics from a map and as a result creates a table that contains the extracted attributes.

===== Inputs =====

^ Name  ^ Type  ^ Description  ^
| Map  | [[Map Type]]  | Map whose attributes will be extracted.  |

===== Optional Inputs =====

^ Name  ^ Type  ^ Description  ^ Default Value  ^
| Extract Dynamic Attributes  | [[Boolean Value Type]]  | If true, the [[Extract Map Attributes#Dynamic attributes|dynamic attributes]] will be calculated.  | True  |
| Extract Statistical Attributes  | [[Boolean Value Type]]  | If true, [[Extract Map Attributes#Statistical attributes|statistical attributes]] will be calculated.  | True  |

===== Outputs =====

^ Name  ^ Type  ^ Description  ^
| Attributes  | [[Lookup Table Type]]  | Table containing the attributes extracted from a map.  |
| Layer Attributes  | [[Table Type]]  | Table containing the layer attributes.  |

===== Group =====

[[Functor List#Map Algebra | Map Algebra]]

===== Notes =====

This functor analyzes all map layers. The resulting table refers to all of them.

The functor employs a lookup table with keys to the attributes. Each key has a predefined name. This name can be used to retrieve the corresponding attribute in [[Calculate Map]], [[Calculate Categorical Map]], [[Calculate Value]] and [[Calculate Lookup Table]].

If it is not possible to determine any of these attributes, the corresponding entry in the lookup table is left blank. It determines the maximum and the minimum values only when there is at least one non null cell on the map.

==== Basic Attributes ====

^ Key  ^ Predefined Name  ^ Description  ^
| 1  | "lines"  | number of lines  |
| 2  | "columns"  | number of columns  |
| 3  | "cells"  | number of cells (number of lines multiplied by the number of columns)  |
| 4  | "layers"  | number of layers  |
| 5  | "cellHeight"  | cell height (in meters)  |
| 6  | "cellWidth"  | cell width (in meters)  |
| 7  | "cellArea"  | cell area (in hectares)  |
| 19  | "cellType"  | [[Extract Map Attributes#Cell Type Codes|cell type code]]  |
| 20  | "nullValue"  | null value  |
| 21  | "registrationCoordinateY"  | registration coordinate Y (this is the coordinate of the top left corner of the registered cell)  |
| 22  | "registrationCoordinateX"  | registration coordinate X (this is the coordinate of the top left corner of the registered cell)  |
| 23  | "registrationCellY"  | coordinate of registration cell Y  |
| 24  | "registrationCellX"  | coordinate of registration cell X  |
| 25  | "rotationY"  | rotation around Y  |
| 26  | "rotationX"  | rotation around X  |
| 27  | "originalCellHeight"  | cell height (cell height from projection - the unit is projection dependent)  |
| 28  | "originalCellWidth"  | cell width (cell height from projection - the unit is projection dependent)  |

==== Dynamic attributes ====

^ Key  ^ Predefined Name  ^ Description  ^
| 8  | "nullCells"  | number of null cells  |
| 9  | "nonNullCells"  | number of non null cells  |
| 10  | "minCell"  | minimum value (excluding null cells)  |
| 11  | "maxCell"  | maximum value (excluding null cells)  |
| 12  | "cellSum"  | sum of the values (excluding null cells)  |

==== Statistical attributes ====

^ Key  ^ Predefined Name  ^ Description  ^
| 13  | "meanCell"  | average (excluding null cells)  |
| 14  | "cellVar"  | variance (excluding null cells)  |
| 15  | "cellStd"  | standard deviation (excluding null cells)  |
| 16  | "modeCell"  | mode (excluding null cells)  |
| 17  | "medianCell"  | median (excluding null cells)  |
| 18  | "uniqueCells"  | total unique occurrences (excluding null cells)  |

==== Cell Type Codes ====

The codes used to represent all the possible [[cell_type_type|cells types]], corresponding to attribute key 19 ("cellType"), are listed below. It is possible to convert the corresponding code back into a [[Cell Type Type|Cell Type]].

^ Key  ^ Cell Type  ^ 
| 0  | Unsigned 1 Bit Integer  |
| 1  | Signed 8 Bit Integer  |
| 2  | Unsigned 8 Bit Integer  |
| 3  | Signed 16 Bit Integer  |
| 4  | Unsigned 16 Bit Integer  |
| 5  | Signed 32 Bit Integer  |
| 6  | Unsigned 32 Bit Integer  |
| 7  | IEEE 754 32 Bit Real  |
| 8  | IEEE 754 64 Bit Real  |

==== Layer Attributes ====

The layer attributes((Currently, only the layer name is the only layer specific attribute returned.)) are returned in a second table. This table has the following format.

^ Column Name  ^ Key or Data?  ^ Column Type  ^ Description  ^
| "Layer_Index"  | Key  | Real  | The index of the corresponding layer  |
| "Layer_Name"  | Key  | String  | The name of the corresponding layer  |
 
===== Internal Name =====

ExtractMapAttributes