skcriteria.agg.electre
module¶
ELimination Et Choix Traduisant la REalité - ELECTRE.
ELECTRE is a family of multi-criteria decision analysis methods that originated in Europe in the mid-1960s. The acronym ELECTRE stands for: ELimination Et Choix Traduisant la REalité (ELimination and Choice Expressing REality).
Usually the ELECTRE Methods are used to discard some alternatives to the problem, which are unacceptable. After that we can use another MCDA to select the best one. The Advantage of using the Electre Methods before is that we can apply another MCDA with a restricted set of alternatives saving much time.
- skcriteria.agg.electre.concordance(matrix, objectives, weights)[source]¶
Calculate the concordance matrix.
- skcriteria.agg.electre.electre1(matrix, objectives, weights, p=0.65, q=0.35)[source]¶
Execute ELECTRE1 without any validation.
- class skcriteria.agg.electre.ELECTRE1(*, p=0.65, q=0.35)[source]¶
Bases:
SKCDecisionMakerABC
Find a kernel of alternatives through ELECTRE-1.
The ELECTRE I model find the kernel solution in a situation where true criteria and restricted outranking relations are given.
That is, ELECTRE I cannot derive the ranking of alternatives but the kernel set. In ELECTRE I, two indices called the concordance index and the discordance index are used to measure the relations between objects
- Parameters:
p (float, optional (default=0.65)) – Concordance threshold. Threshold of how much one alternative is at least as good as another to be significative.
q (float, optional (default=0.35)) – Discordance threshold. Threshold of how much the degree one alternative is strictly preferred to another to be significative.
References
[Roy, 1990] [Roy, 1968] [Tzeng & Huang, 2011]
- property p¶
Concordance threshold.
- property q¶
Discordance threshold.
- skcriteria.agg.electre.weights_outrank(matrix, weights, objectives)[source]¶
Calculate a matrix of comparison of alternatives where the value of each cell determines how many times the value of the criteria weights of the row alternative exceeds those of the column alternative.
Notes
For more information about this matrix please check “Tomada de decisões em cenários complexos” [Gomes et al., 2004], p. 100
- skcriteria.agg.electre.electre2(matrix, objectives, weights, p0=0.65, p1=0.5, p2=0.35, q0=0.65, q1=0.35)[source]¶
Execute ELECTRE2 without any validation.
Deprecated since version 0.8: electre2 implementation will change in version after 0.8
- class skcriteria.agg.electre.ELECTRE2(*args, **kwargs)[source]¶
Bases:
SKCDecisionMakerABC
Find the ranking solution through ELECTRE-2.
ELECTRE II was proposed by Roy and Bertier (1971-1973) to overcome ELECTRE I’s inability to produce a ranking of alternatives. Instead of simply finding the kernel set, ELECTRE II can order alternatives by introducing the strong and the weak outranking relations.
Deprecated since version 0.8: ELECTRE2 implementation will change in version after 0.8
Notes
This implementation is based on the one presented in the book “Tomada de decisões em cenários complexos” [Gomes et al., 2004].
- Parameters:
p0 (float, optional (default=0.65, 0.5, 0.35)) –
Matching thresholds. These are the thresholds that indicate the extent to which an alternative can be considered equivalent, good or very good with respect to another alternative.
These thresholds must meet the condition “1 >= p0 >= p1 >= p2 >= 0”.
p1 (float, optional (default=0.65, 0.5, 0.35)) –
Matching thresholds. These are the thresholds that indicate the extent to which an alternative can be considered equivalent, good or very good with respect to another alternative.
These thresholds must meet the condition “1 >= p0 >= p1 >= p2 >= 0”.
p2 (float, optional (default=0.65, 0.5, 0.35)) –
Matching thresholds. These are the thresholds that indicate the extent to which an alternative can be considered equivalent, good or very good with respect to another alternative.
These thresholds must meet the condition “1 >= p0 >= p1 >= p2 >= 0”.
q0 (float, optional (default=0.65, 0.35)) –
Discordance threshold. Threshold of the degree to which an alternative is equivalent, preferred or strictly preferred to another alternative.
These thresholds must meet the condition “1 >= q0 >= q1 >= 0”.
q1 (float, optional (default=0.65, 0.35)) –
Discordance threshold. Threshold of the degree to which an alternative is equivalent, preferred or strictly preferred to another alternative.
These thresholds must meet the condition “1 >= q0 >= q1 >= 0”.
References
[Gomes et al., 2004] [Roy & Bertier, 1971] [Roy & Bertier, 1973]
- property p0¶
Concordance threshold 0.
- property p1¶
Concordance threshold 1.
- property p2¶
Concordance threshold 2.
- property q0¶
Discordance threshold 0.
- property q1¶
Discordance threshold 1.