"Toward Talent Scientist: Sharing and Learning Together" --- Jingwei Too
- This toolbox offers 13 wrapper feature selection methods
- The
Demo_PSO
provides an example of how to apply PSO on benchmark dataset - Source code of these methods are written based on pseudocode & paper
The main function jfs
is adopted to perform feature selection. You may switch the algorithm by changing the pso
in from FS.pso import jfs
to other abbreviations
- If you wish to use particle swarm optimization ( PSO ) then you may write
from FS.pso import jfs
- If you want to use differential evolution ( DE ) then you may write
from FS.de import jfs
feat
: feature vector matrix ( Instance x Features )label
: label matrix ( Instance x 1 )opts
: parameter settingsN
: number of solutions / population size ( for all methods )T
: maximum number of iterations ( for all methods )k
: k-value in k-nearest neighbor
Acc
: accuracy of validation modelfmdl
: feature selection model ( It contains several results )sf
: index of selected featuresnf
: number of selected featuresc
: convergence curve
import numpy as np import pandas as pd from sklearn.neighbors import KNeighborsClassifier from sklearn.model_selection import train_test_split from FS.pso import jfs # change this to switch algorithm import matplotlib.pyplot as plt # load data data = pd.read_csv('ionosphere.csv') data = data.values feat = np.asarray(data[:, 0:-1]) # feature vector label = np.asarray(data[:, -1]) # label vector # split data into train & validation (70 -- 30) xtrain, xtest, ytrain, ytest = train_test_split(feat, label, test_size=0.3, stratify=label) fold = {'xt':xtrain, 'yt':ytrain, 'xv':xtest, 'yv':ytest} # parameter k = 5 # k-value in KNN N = 10 # number of particles T = 100 # maximum number of iterations w = 0.9 c1 = 2 c2 = 2 opts = {'k':k, 'fold':fold, 'N':N, 'T':T, 'w':w, 'c1':c1, 'c2':c2} # perform feature selection fmdl = jfs(feat, label, opts) sf = fmdl['sf'] # model with selected features num_train = np.size(xtrain, 0) num_valid = np.size(xtest, 0) x_train = xtrain[:, sf] y_train = ytrain.reshape(num_train) # Solve bug x_valid = xtest[:, sf] y_valid = ytest.reshape(num_valid) # Solve bug mdl = KNeighborsClassifier(n_neighbors = k) mdl.fit(x_train, y_train) # accuracy y_pred = mdl.predict(x_valid) Acc = np.sum(y_valid == y_pred) / num_valid print("Accuracy:", 100 * Acc) # number of selected features num_feat = fmdl['nf'] print("Feature Size:", num_feat) # plot convergence curve = fmdl['c'] curve = curve.reshape(np.size(curve,1)) x = np.arange(0, opts['T'], 1.0) + 1.0 fig, ax = plt.subplots() ax.plot(x, curve, 'o-') ax.set_xlabel('Number of Iterations') ax.set_ylabel('Fitness') ax.set_title('PSO') ax.grid() plt.show()
import numpy as np import pandas as pd from sklearn.neighbors import KNeighborsClassifier from sklearn.model_selection import train_test_split from FS.ga import jfs # change this to switch algorithm import matplotlib.pyplot as plt # load data data = pd.read_csv('ionosphere.csv') data = data.values feat = np.asarray(data[:, 0:-1]) label = np.asarray(data[:, -1]) # split data into train & validation (70 -- 30) xtrain, xtest, ytrain, ytest = train_test_split(feat, label, test_size=0.3, stratify=label) fold = {'xt':xtrain, 'yt':ytrain, 'xv':xtest, 'yv':ytest} # parameter k = 5 # k-value in KNN N = 10 # number of chromosomes T = 100 # maximum number of generations CR = 0.8 MR = 0.01 opts = {'k':k, 'fold':fold, 'N':N, 'T':T, 'CR':CR, 'MR':MR} # perform feature selection fmdl = jfs(feat, label, opts) sf = fmdl['sf'] # model with selected features num_train = np.size(xtrain, 0) num_valid = np.size(xtest, 0) x_train = xtrain[:, sf] y_train = ytrain.reshape(num_train) # Solve bug x_valid = xtest[:, sf] y_valid = ytest.reshape(num_valid) # Solve bug mdl = KNeighborsClassifier(n_neighbors = k) mdl.fit(x_train, y_train) # accuracy y_pred = mdl.predict(x_valid) Acc = np.sum(y_valid == y_pred) / num_valid print("Accuracy:", 100 * Acc) # number of selected features num_feat = fmdl['nf'] print("Feature Size:", num_feat) # plot convergence curve = fmdl['c'] curve = curve.reshape(np.size(curve,1)) x = np.arange(0, opts['T'], 1.0) + 1.0 fig, ax = plt.subplots() ax.plot(x, curve, 'o-') ax.set_xlabel('Number of Iterations') ax.set_ylabel('Fitness') ax.set_title('GA') ax.grid() plt.show()
- Python 3
- Numpy
- Pandas
- Scikit-learn
- Matplotlib
- Note that the methods are altered so that they can be used in feature selection tasks
- The extra parameters represent the parameter(s) other than population size and maximum number of iterations
- Click on the name of method to view how to set the extra parameter(s)
- Use the
opts
to set the specific parameters - If you do not set extra parameters then the algorithm will use default setting in here
No. | Abbreviation | Name | Year | Extra Parameters |
---|---|---|---|---|
13 | hho | Harris Hawk Optimization | 2019 | No |
12 | ssa | Salp Swarm Algorithm | 2017 | No |
11 | woa | Whale Optimization Algorithm | 2016 | Yes |
10 | sca | Sine Cosine Algorithm | 2016 | Yes |
09 | ja | Jaya Algorithm | 2016 | No |
08 | gwo | Grey Wolf Optimizer | 2014 | No |
07 | fpa | Flower Pollination Algorithm | 2012 | Yes |
06 | ba | Bat Algorithm | 2010 | Yes |
05 | fa | Firefly Algorithm | 2010 | Yes |
04 | cs | Cuckoo Search Algorithm | 2009 | Yes |
03 | de | Differential Evolution | 1997 | Yes |
02 | pso | Particle Swarm Optimization | 1995 | Yes |
01 | ga | Genetic Algorithm | - | Yes |