Documentation
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Index ¶
- func FitnessClassic(leftSpace, itemCost, _ int) float64
- func FitnessWithBucketLeftSpacePreferringBigItems(leftSpace, itemCost, bucketSize int) float64
- func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignment(leftSpace, itemCost, bucketSize int) float64
- func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignmentPunishPerfectlyFittedItems(leftSpace, itemCost, bucketSize int) float64
- func FitnessWithBucketLeftSpacePreferringSmallItems(leftSpace, itemCost, bucketSize int) float64
- func FitnessWithBucketLeftSpacePreferringSmallItemsPunishPerfectlyFittedItems(leftSpace, itemCost, bucketSize int) float64
- func FitnessWithBucketSize(leftSpace, itemCost, bucketSize int) float64
- type BestFit
- type FitnessFunc
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func FitnessClassic ¶
FitnessClassic is a fitness function defined by classic best-fit algorithm for classic bin packing problem. It defines the fitness as a left space after element assignment.
func FitnessWithBucketLeftSpacePreferringBigItems ¶
FitnessWithBucketLeftSpacePreferringBigItems is a fitness function that takes into account free space after assignment and free space before assignment. The more space before the assignment and less space after the assignment the better. It prefers big items that leave as little space as possible after assignment.
func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignment ¶
func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignment( leftSpace, itemCost, bucketSize int) float64
FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignment is a fitness function that takes into account free space after assignment and free space before assignment. The less space before the assignment and less space after the assignment the better. It prefers almost full buckets and items that leave as little space as possible after assignment.
func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignmentPunishPerfectlyFittedItems ¶
func FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignmentPunishPerfectlyFittedItems( leftSpace, itemCost, bucketSize int) float64
FitnessWithBucketLeftSpacePreferringLittleSpaceBeforeAndAfterAssignmentPunishPerfectlyFittedItems is a fitness function that takes into account free space after assignment and free space before assignment. The less space before the assignment and less space after the assignment the better. It prefers almost full buckets and items that leave as little space as possible after assignment. It punishes perfectly fitted items by giving them the fitness of infinity.
func FitnessWithBucketLeftSpacePreferringSmallItems ¶
FitnessWithBucketLeftSpacePreferringSmallItems is a fitness function that takes into account free space after assignment and free space before assignment. The less space before the assignment and most space after the assignment the better. It prefers small items that leave as much space as possible after assignment. If item is perfectly fitted it returns 0.
func FitnessWithBucketLeftSpacePreferringSmallItemsPunishPerfectlyFittedItems ¶
func FitnessWithBucketLeftSpacePreferringSmallItemsPunishPerfectlyFittedItems( leftSpace, itemCost, bucketSize int) float64
FitnessWithBucketLeftSpacePreferringSmallItemsPunishPerfectlyFittedItems is a fitness function that takes into account free space after assignment and free space before assignment. The less space before the assignment and most space after the assignment the better. It prefers small items that leave as much space as possible after assignment. It punishes perfectly fitted items by giving them the fitness of infinity.
func FitnessWithBucketSize ¶
FitnessWithBucketSize is a fitness function that takes into account the size of a bucket, computing relative free space after assignment to overall bucket size. The less space after assignment and the bucket is bigger the better. It prefers big buckets and well-fitted items.
Types ¶
type BestFit ¶
type BestFit struct {
FitnessFunc FitnessFunc
}
BestFit is an optimizer that implements the best-fit algorithm expanded to solve the bin packing problem with heterogeneous bins and items with different sizes that depend on the bin choice. The algorithm uses FitnessFunc to choose "best" bucket. Unfortunately, due to the extended problem, it is not possible to implement best-fit using a balanced binary tree, therefore the implementation works in O(v*n) time.
type FitnessFunc ¶
FitnessFunc defines what means "best" assignment. The lower the value of FitnessFunc the better the assignment would be. It returns a negative value for an item that cannot be assigned to the given bucket, and a positive value if the item can be assigned and leave some space in it.
Source Files