src/stats/Connectedness.js

  1.  
  2. import Stat from "./Stat.js"
  3. import ConnectedComponentsByCell from "./ConnectedComponentsByCell.js"
  4.  
  5. /** This Stat computes the 'connectedness' of cells on the grid. 
  6. 	Keys are the {@link CellId} of all cells on the grid, corresponding values the
  7. 	connectedness of the corresponding cell. 
  8. 	
  9. 	@example
  10. 	* let CPM = require( "path/to/build" )
  11. 	*
  12. 	* // Make a CPM, seed a cell, and get the Connectedness
  13. 	* let C = new CPM.CPM( [100,100], { 
  14. 	* 	T:20,
  15. 	* 	J:[[0,20],[20,10]],
  16. 	* 	V:[0,200],
  17. 	* 	LAMBDA_V:[0,2]
  18. 	* } )
  19. 	* let gm = new CPM.GridManipulator( C )
  20. 	* gm.seedCell(1)
  21. 	* for( let t = 0; t < 100; t++ ){ C.timeStep() }
  22. 	* C.getStat( CPM.Connectedness )
  23. */
  24. class Connectedness extends Stat {
  25.  
  26. 	/** This method computes the connectedness of a specific cell. 
  27. 	@return {number} the connectedness value of this cell, a number between 0 and 1.
  28. 	*/
  29. 	connectednessOfCell( cellid ){
  30. 	
  31. 		let ccbc = this.M.getStat( ConnectedComponentsByCell )
  32. 		const v = ccbc[cellid]
  33. 	
  34. 		//let s = {}, r = {}, i, j
  35. 		let s = 0, r = 0
  36. 		
  37. 		for( let comp in Object.keys( v ) ){
  38. 			let volume = v[comp].length
  39. 			s += volume
  40. 		}
  41. 		for( let comp in Object.keys( v ) ){
  42. 			let volume = v[comp].length
  43. 			r += (volume/s)*(volume/s)
  44. 		}
  45. 		
  46. 		return r
  47.  
  48. 	}
  49.  
  50. 	/** The compute method of Connectedness creates an object with 
  51. 	connectedness of each cell on the grid.
  52. 	@return {CellObject} object with for each cell on the grid
  53. 	a connectedness value. 
  54. 	*/
  55. 	compute(){
  56. 		// initialize the object
  57. 		let connectedness = { }
  58. 		// The this.M.pixels() iterator returns coordinates and cellid for all 
  59. 		// non-background pixels on the grid. See the appropriate Grid class for
  60. 		// its implementation.
  61. 		for( let ci of this.M.cellIDs() ){
  62. 			connectedness[ci] = this.connectednessOfCell( ci )
  63. 		}
  64. 		return connectedness
  65. 	}
  66. }
  67.  
  68. export default Connectedness