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calc_distance_to_feature_map [2011/07/31 01:28]
admin [Notes] 		calc_distance_to_feature_map [2026/08/28 03:09] (current)
hermann Sync from local documentation review
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-====== Calc Distance To Feature Map ====== ​+====== Calc Distance To Feature Map ======
  
 ===== Description ===== ===== Description =====
  
-This functor calculates ​a map representing the frontage ​distance ​(in meters) between a cell and the closest ​cell representing a feature.+Calculates ​a map representing the Euclidean ​distance, in meters, from every cell to the nearest ​cell representing a feature.
  
 ===== Inputs ===== ===== Inputs =====
  
-^ Name   ​^ Type                                       ​^ Description ​                                                                                                                                                                                                                                                                   ^ +^ Name  ^ Type  ^ Description ​ ^ 
-| Source | [[Categorical Map Type|Categorical Map  ​]] | Map containing the features to which distances ​will be calculated. A feature is represented by a non-null value. ​Data cell type of this map must be "​Signed 32 Bit Integer"​ or an error will be reported. ​|+| Source ​ | [[Categorical Map Type]] ​ | Map for which distances ​are calculated. A feature is represented by any non-null value. ​ |
  
-^ Name                         ^ Type                                       ^ Description ​                                                                                                                                                                    ^ Default Value          ^ +===== Optional Inputs =====
-| Mask                         | [[Categorical Map Type|Categorical Map ]] | A map used to mask the distance calculation on its null cell areas. Data cell type of this map must be compatible with "​Signed 32 Bit Integer"​ or an error will be reported. ​    | None                   | +
-| Cell type                    | [[Cell Type Type|Cell Type ]]             | Data cell type.                                                                                                                                                                  | Signed 32 Bit Integer ​ | +
-| Null Value                   | [[Int Type|Int ]]                         | Null value of the distance map.                                                                                                                                                  | -2147483648 ​           | +
-| Truncate Distance ​           | [[Bool Type|Bool ]]                       | If true, distance values that exceed the greatest value of the output map will be truncated, instead of reporting an error. ​                                                     | False                  | +
-| Ignore Unreachable Sources ​  | [[Bool Type|Bool ]]                       | If true, feature cells completely surrounded by other feature cells are ignored. ​                                                                                                | True                   | +
-| Ignore Cross Inside Sources ​ | [[Bool Type|Bool ]]                       | If true, feature cells surrounded by other feature cells on the horizontal and vertical axis will be ignored. To have an effect, "​Ignore Unreachable Sources"​ must also be true. | True                   |+
  
-===== Output =====+^ Name  ^ Type  ^ Description ​ ^ Default Value  ^ 
 +| Mask  | [[Map Type]] ​ | Map restricting which cells have their distance calculated: only cells whose corresponding cell in Mask is non-null have a distance calculated. ​ | None  | 
 +| Cell Type  | [[Cell Type Type]] ​ | Cell type of the distance map.  | Signed 32 Bit Integer ​ | 
 +| Null Value  | [[Null Value Type]] ​ | Null value of the distance map.  | -2147483648 ​ | 
 +| Truncate Distance ​ | [[Boolean Value Type]] ​ | If true, a distance exceeding the largest value representable in the output map is truncated to that largest value instead of reporting an error. This is an advanced port.  | No  |
  
-^ Name     ​^ Type              ^ Description ​                                                                                                     ^ +===== Outputs ===== 
-| Distance | [[Map Type|Map ]] | The distance map. The distances ​are represented ​in meters. Map format has the same dimensions ​of the source map. |+ 
 +^ Name  ^ Type  ^ Description ​ ^ 
 +| Distance ​ | [[Map Type]] ​ | Map of distances, in meters, with the same dimensions ​as Source.  |
  
 ===== Group ===== ===== Group =====
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 ===== Notes ===== ===== Notes =====
  
-The calculated distance ​is the [[wp>​Euclidean_distance|Euclidean distance]] and the unit used is the meter.+Mask only restricts which cells receive a calculated distance ​in the output; it has no effect on which cells of Source are collected as features, so a feature located outside ​the area defined by Mask still influences the result. 
 + 
 +Raises an error if Null Value is not compatible with Cell Type.
  
-The mask does not interfere with distance calculations to cells located beyond null cells.+Reports a warning if Cell Type could degrade performance.
  
 ===== Internal Name ===== ===== Internal Name =====