OEFPDatabaseOptions

class OEFPDatabaseOptions

The OEFPDatabaseOptions class allows setting options on a per-search basis. This class is used to control the behavior of:

• the following methods of the OEFPDatabase class

  • OEFPDatabase.GetScores

  • OEFPDatabase.GetSortedScores

• the following methods of the OEFastFPDatabase class

  • OEFastFPDatabase.GetAllScores

  • OEFastFPDatabase.GetHistogram

  • OEFastFPDatabase.GetSortedScores

  • OEFastFPDatabase.GetRawScores

  • OEFastFPDatabase.SortedSearch

See also

• Example code in Similarity calculation with an option class section

• Example code in Sorted similarity calculation with an option class section

• Example code in Searching fast fingerprint database section

The OEFPDatabaseOptions class stores the following properties:

Property	Get method	Set method	Corresponding namespace / type
cutoff value	GetCutoff	SetCutoff / HasCutoff	floating point number
order of sorting	GetDescendingOrder	SetDescendingOrder	boolean
max number of scores	GetLimit	SetLimit	integer 0 means no limit
similarity method	GetSimFunc	SetSimFunc	OESimMeasure
\(\alpha\) and \(\beta\) for Tversky	GetTverskyAlpha / GetTverskyBeta	SetTverskyCoeffs	floating point number
numper of processors	GetNumProcessors	SetNumProcessors	integer 0 means OEGetNumProcessors

Constructors

OEFPDatabaseOptions() -> OEFPDatabaseOptions

Default constructor.

Default parameters of OEFPDatabaseOptions

Property	Default value
cutoff value	no cutoff set
order of sorting	true (means descending order)
max number of scores	0 (means no limit)
similarity method	OESimMeasure_Tanimoto
\(\alpha\) and \(\beta\) for Tversky	\(\alpha = 0.95, \beta = 0.05\)
number of processors	1

OEFPDatabaseOptions(limit: int, simfunc: int) -> OEFPDatabaseOptions

Constructs an OEFPDatabaseOptions object with a limit on the number of similarity scores returned and a similarity method from the OESimMeasure namespace. The returned scores will be in descending order and applying no cutoff value.

OEFPDatabaseOptions(arg2: OEFPDatabaseOptions) -> OEFPDatabaseOptions

Copy constructors.

ClearCutoff

ClearCutoff() -> None

Removes the cutoff value previously set by the OEFPDatabaseOptions.SetCutoff method. After clearing the cutoff value, OEFPDatabaseOptions.HasCutoff method will return false.

See also

• OEFPDatabaseOptions.HasCutoff method

• OEFPDatabaseOptions.GetCutoff method

• OEFPDatabaseOptions.SetCutoff method

GetCutoff

GetCutoff() -> float

Returns the cutoff value previously set by the OEFPDatabase.SetCutoff method.

See also

• OEFPDatabaseOptions.ClearCutoff method

• OEFPDatabaseOptions.HasCutoff method

• OEFPDatabaseOptions.SetCutoff method

GetDescendingOrder

GetDescendingOrder() -> bool

Returns whether the similarity scores will be returned in descending or in ascending order.

See also

• OEFPDatabaseOptions.SetDescendingOrder method

GetLimit

GetLimit() -> int

Returns the maximum number of similarity scores returned.

See also

• OEFPDatabaseOptions.SetLimit method

GetSimFunc

GetSimFunc() -> int

Returns the similarity measure used to evaluate fingerprint similarities. The return value is taken from the OESimMeasure namespace.

See also

• OEFPDatabaseOptions.SetSimFunc method

GetNumProcessors

GetNumProcessors() -> int

Returns the number of threads that are used to search fingerprints when calling the OEFastFPDatabase.SortedSearch method.

See also

• OEFPDatabaseOptions.SetNumProcessors method

GetTverskyAlpha

GetTverskyAlpha() -> float

Returns the \(\alpha\) parameter of the Tversky similarity.

See also

• OEFPDatabaseOptions.SetTverskyCoeffs method

• OETverskySim class

GetTverskyBeta

GetTverskyBeta() -> float

Returns the \(\beta\) parameter of the Tversky similarity.

See also

• OEFPDatabaseOptions.SetTverskyCoeffs method

• OETverskySim class

HasCutoff

HasCutoff() -> bool

Returns whether the cutoff value of the OEFPDatabaseOptions object has been set by the OEFPDatabaseOptions.SetCutoff method.

See also

• OEFPDatabaseOptions.ClearCutoff method

• OEFPDatabaseOptions.GetCutoff method

• OEFPDatabaseOptions.SetCutoff method

SetCutoff

SetCutoff(cutoff: float) -> None

Sets the cutoff value of the OEFPDatabaseOptions object.

See also

• OEFPDatabaseOptions.ClearCutoff method

• OEFPDatabaseOptions.GetCutoff method

• OEFPDatabaseOptions.HasCutoff method

SetDescendingOrder

SetDescendingOrder(descending: bool = True) -> None

Sets whether the similarity scores will be returned in descending or in ascending order.

Note

This method has no effect on the OEFPDatabase.GetScores method.

See also

• OEFPDatabaseOptions.GetDescendingOrder method

SetLimit

SetLimit(limit: int) -> None

Sets the maximum number of similarity scores returned.

limit

If it is set to zero, then all similarity scores are returned.

Note

This method has no effect on the OEFPDatabase.GetScores method.

See also

• OEFPDatabaseOptions.GetLimit method

SetSimFunc

SetSimFunc(simfunc: int) -> None

Sets the similarity measure used to evaluate fingerprint similarities.

simtype

This value has to be from the OESimMeasure namespace.

See also

• OEFPDatabaseOptions.GetSimFunc method

SetNumProcessors

SetNumProcessors(nrps: int) -> None

Sets the number of threads that are used to search fingerprints when calling the OEFastFPDatabase.SortedSearch method. When set to 0, the number of processors used will be the number returned by the OEGetNumProcessors function.

Multi-threaded fingerprint search is currently only available in OEFastFPDatabaseMemoryType_MemoryMapped and OEFastFPDatabaseMemoryType_InMemory modes.

SetTverskyCoeffs

SetTverskyCoeffs(alpha: float = 0.95, beta: float = 0.05) -> None

Sets \(\alpha\) and \(\beta\) parameters for the Tversky similarity.

See also

• OEFPDatabaseOptions.GetTverskyAlpha method

• OEFPDatabaseOptions.GetTverskyBeta method

• OETverskySim class