I am using XGboost for a binary prediction problem. I tested my model with several features and had some good results.
After adding one feature to the model and calculating the feature importance. The importance of this feature showed to be very high and far superior to other features.
However, when testing the model the test score drops considerably.
Is there an explanation for this kind of behaviour ?
There are at least a few ways to run feature importance experiments.
# Let's load the packages
import numpy as np
import pandas as pd
from sklearn.datasets import load_boston
from sklearn.model_selection import train_test_split
from sklearn.ensemble import RandomForestRegressor
from sklearn.inspection import permutation_importance
import shap
from matplotlib import pyplot as plt
plt.rcParams.update({'figure.figsize': (12.0, 8.0)})
plt.rcParams.update({'font.size': 14})
boston = load_boston()
X = pd.DataFrame(boston.data, columns=boston.feature_names)
y = boston.target
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.25, random_state=12)
rf = RandomForestRegressor(n_estimators=100)
rf.fit(X_train, y_train)
# 1
rf.feature_importances_
plt.barh(boston.feature_names, rf.feature_importances_)
sorted_idx = rf.feature_importances_.argsort()
plt.barh(boston.feature_names[sorted_idx], rf.feature_importances_[sorted_idx])
plt.xlabel("Random Forest Feature Importance")
# 2
perm_importance = permutation_importance(rf, X_test, y_test)
sorted_idx = perm_importance.importances_mean.argsort()
plt.barh(boston.feature_names[sorted_idx], perm_importance.importances_mean[sorted_idx])
plt.xlabel("Permutation Importance")
# 3
explainer = shap.TreeExplainer(rf)
shap_values = explainer.shap_values(X_test)
shap.summary_plot(shap_values, X_test, plot_type="bar")
Also, you can certainly add more data into your model. Models, almost without exception, produce more accurate results when they 'see' more data. Finally, you can always test other models on your dataset and see how they perform. Today at work I tested an XGboost model and a RandomForestRegressor model. I expected the former to perform better, but the latter actually performed much better. It's almost impossible to guess which model will perform better over any given dataset, you have to try multiple models, check the predictive capabilities of each, and pick the one (or maybe two) that performs the best. Having said that, you can try something like this.
import time
import numpy as np
import matplotlib.pyplot as plt
from sklearn import cluster, datasets
from sklearn.neighbors import kneighbors_graph
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import train_test_split
np.random.seed(0)
pd.set_option('display.max_columns', 500)
#df = pd.read_csv('C:\\your_path_here\\test.csv')
#print('done!')
#df = df[:10000]
#df = df.fillna(0)
#df = df.dropna()
X = df[['RatingScore',
'Par',
'Term',
'TimeToMaturity',
'LRMScore',
'Coupon',
'Price']]
#select your target variable
y = df[['Spread']]
#train test split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42)
colors = np.array([x for x in 'bgrcmykbgrcmykbgrcmykbgrcmyk'])
colors = np.hstack([colors] * 20)
clustering_names = [
'MiniBatchKMeans', 'AffinityPropagation', 'MeanShift',
'SpectralClustering', 'Ward', 'AgglomerativeClustering',
'DBSCAN', 'Birch']
plt.figure(figsize=(len(clustering_names) * 2 + 3, 9.5))
plt.subplots_adjust(left=.02, right=.98, bottom=.001, top=.96, wspace=.05,
hspace=.01)
plot_num = 1
blobs = datasets.make_blobs(n_samples=n_samples, random_state=8)
# normalize dataset for easier parameter selection
X = StandardScaler().fit_transform(X)
# estimate bandwidth for mean shift
bandwidth = cluster.estimate_bandwidth(X, quantile=0.3)
# connectivity matrix for structured Ward
connectivity = kneighbors_graph(X, n_neighbors=10, include_self=False)
# make connectivity symmetric
connectivity = 0.5 * (connectivity + connectivity.T)
# create clustering estimators
ms = cluster.MeanShift(bandwidth=bandwidth, bin_seeding=True)
two_means = cluster.MiniBatchKMeans(n_clusters=2)
ward = cluster.AgglomerativeClustering(n_clusters=2, linkage='ward',
connectivity=connectivity)
spectral = cluster.SpectralClustering(n_clusters=2,
eigen_solver='arpack',
affinity="nearest_neighbors")
dbscan = cluster.DBSCAN(eps=.2)
affinity_propagation = cluster.AffinityPropagation(damping=.9,
preference=-200)
average_linkage = cluster.AgglomerativeClustering(
linkage="average", affinity="cityblock", n_clusters=2,
connectivity=connectivity)
birch = cluster.Birch(n_clusters=2)
clustering_algorithms = [
two_means, affinity_propagation, ms, spectral, ward, average_linkage,
dbscan, birch]
for name, algorithm in zip(clustering_names, clustering_algorithms):
# predict cluster memberships
t0 = time.time()
algorithm.fit(X)
t1 = time.time()
if hasattr(algorithm, 'labels_'):
y_pred = algorithm.labels_.astype(np.int)
else:
y_pred = algorithm.predict(X)
# plot
plt.subplot(4, len(clustering_algorithms), plot_num)
if i_dataset == 0:
plt.title(name, size=18)
plt.scatter(X[:, 0], X[:, 1], color=colors[y_pred].tolist(), s=10)
if hasattr(algorithm, 'cluster_centers_'):
centers = algorithm.cluster_centers_
center_colors = colors[:len(centers)]
plt.scatter(centers[:, 0], centers[:, 1], s=100, c=center_colors)
plt.xlim(-2, 2)
plt.ylim(-2, 2)
plt.xticks(())
plt.yticks(())
plt.text(.99, .01, ('%.2fs' % (t1 - t0)).lstrip('0'),
transform=plt.gca().transAxes, size=15,
horizontalalignment='right')
plot_num += 1
plt.show()
Finally, consider looping through several regression, or classification, models in one go, and getting the results for each.
from sklearn.linear_model import LinearRegression
regressor = LinearRegression()
regressor.fit(X_train, y_train)
from sklearn import linear_model
import statsmodels.api as sm
X = X
y = y
# Note the difference in argument order
model = sm.OLS(y, X).fit()
predictions = model.predict(X) # make the predictions by the model
# Print out the statistics
model.summary()
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 0.2, random_state = 0)
from sklearn.linear_model import LinearRegression
from sklearn.linear_model import SGDRegressor
from sklearn.neighbors import KNeighborsRegressor
from sklearn.tree import DecisionTreeRegressor
from sklearn.ensemble import RandomForestRegressor
from sklearn.ensemble import GradientBoostingRegressor
from sklearn.linear_model import TweedieRegressor
from sklearn.linear_model import PoissonRegressor
from sklearn.linear_model import Ridge
from sklearn.linear_model import Lasso
from sklearn.svm import LinearSVR
from sklearn.metrics import mean_squared_error
from sklearn.metrics import mean_absolute_error
regressors = [
LinearRegression(),
SGDRegressor(),
KNeighborsRegressor(),
DecisionTreeRegressor(),
RandomForestRegressor(),
GradientBoostingRegressor(),
TweedieRegressor(),
PoissonRegressor(),
Ridge(),
Lasso()
]
import pandas as pd
# Logging for Visual Comparison
log_cols=["Regressor", "RMSE", "MAE"]
log = pd.DataFrame(columns=log_cols)
for reg in regressors:
reg.fit(X_train, y_train)
name = reg.__class__.__name__
print(reg.score(X_test, y_test))
y_pred = reg.predict(X_test)
lr_mse = mean_squared_error(y_pred, y_test)
lr_rmse = np.sqrt(lr_mse)
print(name + ' RMSE: %.4f' % lr_rmse)
lin_mae = mean_absolute_error(y_pred, y_test)
print(name + ' MAE: %.4f' % lin_mae)
log_entry = pd.DataFrame([[name, lr_rmse, lin_mae]], columns=log_cols)
log = log.append(log_entry)
print("="*30)
import seaborn as sns
import matplotlib as plt
sns.set_color_codes("muted")
sns.barplot(x='RMSE', y='Regressor', data=log, color="b")
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.colors import ListedColormap
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.datasets import make_moons, make_circles, make_classification
from sklearn.neural_network import MLPClassifier
from sklearn.gaussian_process.kernels import RBF
from sklearn.naive_bayes import GaussianNB
from sklearn.metrics import accuracy_score, log_loss
from sklearn.neighbors import KNeighborsClassifier
from sklearn.gaussian_process import GaussianProcessClassifier
from sklearn.tree import DecisionTreeClassifier
from sklearn.ensemble import RandomForestClassifier, AdaBoostClassifier, GradientBoostingClassifier
from sklearn.discriminant_analysis import QuadraticDiscriminantAnalysis
from sklearn.svm import SVC
from sklearn.datasets import load_iris
iris = load_iris()
iris
# Step 2: Separating the data into dependent and independent variables
X = iris.data[:, :2] # we only take the first two features.
y = iris.target
# Step 3: Splitting the dataset into the Training set and Test set
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size = 0.2, random_state = 0)
classifiers = [
GaussianNB(),
MLPClassifier(),
KNeighborsClassifier(),
GaussianProcessClassifier(),
DecisionTreeClassifier(),
RandomForestClassifier(),
AdaBoostClassifier(),
GradientBoostingClassifier(),
QuadraticDiscriminantAnalysis()]
import pandas as pd
# Logging for Visual Comparison
log_cols=["Classifier", "Accuracy"]
log = pd.DataFrame(columns=log_cols)
for clf in classifiers:
clf.fit(X_train, y_train)
name = clf.__class__.__name__
print("="*30)
print(name)
print('****Results****')
train_predictions = clf.predict(X_test)
acc = accuracy_score(y_test, train_predictions)
print("Accuracy: {:.4%}".format(acc))
log_entry = pd.DataFrame([[name, acc*100]], columns=log_cols)
log = log.append(log_entry)
print("="*30)
import seaborn as sns
import matplotlib as plt
sns.set_color_codes("muted")
sns.barplot(x='Accuracy', y='Classifier', data=log, color="b")
I'm trying to run this SVM using stratified K fold in Python,however I keep on getting the error like below
from sklearn.model_selection import train_test_split
from sklearn.svm import SVC
from sklearn.utils import shuffle
from sklearn import preprocessing
from sklearn.preprocessing import MinMaxScaler
from sklearn.model_selection import StratifiedKFold
from sklearn.metrics import accuracy_score, zero_one_loss, confusion_matrix
import pandas as pd
import numpy as np
z = pd.read_csv('/home/User/datasets/gtzan.csv', header=0)
X = z.iloc[:, :-1]
y = z.iloc[:, -1:]
X = np.array(X)
y = np.array(y)
# Performing standard scaling
scaler = preprocessing.MinMaxScaler()
X_scaled = scaler.fit_transform(X)
# Defining the SVM with 'rbf' kernel
svc = SVC(kernel='rbf', C=100, random_state=50)
#X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.10, shuffle=True)
skf = StratifiedKFold(n_splits=10, shuffle=True)
accuracy_score = []
#skf.get_n_splits(X, y)
for train_index, test_index in skf.split(X, y):
X_train, X_test = X_scaled[train_index], X_scaled[test_index]
y_train, y_test = y[train_index], y[test_index]
# Training the model
svc.fit(X_train, np.ravel(y_train))
# Prediction on test dataste
y_pred = svc.predict(X_test)
# Obtaining the accuracy scores of the model
score = accuracy_score(y_test, y_pred)
accuracy_score.append(score)
# Print the accuarcy of the svm model
print('accuracy score: %0.3f' % np.mean(accuracy_score))
however, it gives me an error like below
Traceback (most recent call last):
File "/home/User/Test_SVM.py", line 55, in <module>
score = accuracy_score(y_test, y_pred)
TypeError: 'list' object is not callable
What makes this score list uncallable and how do I fix this error?
accuracy_scoreis a list in my code and I was also calling the same list as a function, which is overriding the existing functionality of function accuarcy_score. Changed the list name to acc_score which solved the problem.
How can I deal with polynomial degree when I want to save a polynomial model, sicne this info is not being saved!
import pandas as pd
import numpy as np
import joblib
from sklearn.preprocessing import PolynomialFeatures
from sklearn.linear_model import LinearRegression
from sklearn.model_selection import train_test_split
df = pd.DataFrame({
"a": np.random.uniform(0.0, 1.0, 1000),
"b": np.random.uniform(10.0, 14.0, 1000),
"c": np.random.uniform(100.0, 1000.0, 1000)})
def data():
X_train, X_val, y_train, y_val = train_test_split(df.iloc[:, :2].values,
df.iloc[:, 2].values,
test_size=0.2,
random_state=1340)
return X_train, X_val, y_train, y_val
X_train, X_val, y_train, y_val = data()
poly_reg = PolynomialFeatures(degree = 2)
X_poly = poly_reg.fit_transform(X_train)
poly_reg_model = LinearRegression().fit(X_poly, y_train)
poly_model = joblib.dump(poly_reg_model, 'themodel')
y_pred = poly_reg_model.predict(poly_reg.fit_transform(X_val))
themodel = joblib.load('themodel')
Now, if I try to predict:
themodel.predict(X_val), I am receiving:
ValueError: matmul: Input operand 1 has a mismatch in its core dimension 0, with gufunc signature (n?,k),(k,m?)->(n?,m?) (size 6 is different from 2)
I have to do:
pol_feat = PolynomialFeatures(degree=2)
themodel.predict(pol_feat.fit_transform(X_val))
in order to work.
So, how can i store this info in order to be able to use the model for prediction?
You have to pickle trained PolynomialFeatures also:
# train and pickle
poly_reg = PolynomialFeatures(degree = 2)
X_poly = poly_reg.fit_transform(X_train)
poly_reg_model = LinearRegression().fit(X_poly, y_train)
joblib.dump(poly_reg_model, 'themodel')
joblib.dump(poly_reg, 'poilynomia_features_model')
# load and predict
poilynomia_features_model = joblib.load('poilynomia_features_model')
themodel = joblib.load('themodel')
X_val_prep = poilynomia_features_model.transform(X_val)
predictions = themodel.predict(X_val_prep)
But better will wrap all the steps in the single pipeline:
pipeline = Pipeline(steps=[('poilynomia', PolynomialFeatures()),
('lr', LinearRegression())])
pipeline.fit(X_train, y_train)
pipeline.predict(X_val)
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from sklearn.linear_model import LinearRegression
from sklearn.feature_selection import RFECV
from sklearn.svm import SVR
housing = pd.read_csv('boston.csv')
x = housing.iloc[:, 0:13].values
y = housing.iloc[:, 13:14].values
y = np.ravel(y)
from sklearn.model_selection import train_test_split
x_train, x_test, y_train, y_test = train_test_split(x, y, test_size = 0.33, random_state = 0)
y_train = np.ravel(y_train)
regressor = SVR(kernel = 'poly', degree=2)
regressor.fit(x_train, y_train)
rfecv = RFECV(estimator = regressor, cv=5, scoring='accuracy')
After executing above line (i.e. rfecv) I get the following error:
"RuntimeError: The classifier does not expose "coef_" or "feature_importances_" attributes"
What am I doing wrong ???
You need to fit it afterwards, change it to:
regressor = SVR(kernel = 'poly', degree=2)
rfecv = RFECV(estimator = regressor, cv=5, scoring='accuracy')
rfecv = rfec.fit(x_train, y_train)
import math
import numpy as np
import pandas as pd
#from pandas import DataFrame
from sklearn import preprocessing,cross_validation
from sklearn.linear_model import LogisticRegression
#from sklearn.cross_validation import train_test_split
from numpy import loadtxt, where
from pylab import scatter, show, legend, xlabel, ylabel
# scale larger positive and values to between -1,1 depending on the largest
# value in the data
min_max_scaler = preprocessing.MinMaxScaler(feature_range=(0, 1))
df = pd.read_excel("Cryotherapy.xlsx", header=0)
# clean up data
df.columns = ["sex","age","Time","Number_of_Warts", "Type",
"Area","Result_of_Treatment"]
x = df["Result_of_Treatment"]
X = df[["Type","Area",]]
X = np.array(X)
X = min_max_scaler.fit_transform(X)
Y = df["Result_of_Treatment"]
Y = np.array(Y)
X_train, X_test, Y_train, Y_test = cross_validation.train_test_split(X, Y,
test_size=0.4)
# train scikit learn model
clf = LogisticRegression()
clf.fit(X_train, Y_train)
accuracy = clf.score(X_test,Y_test)
print(accuracy)
Try passing a random_state into the train_test_split function. If you do not do this then the data is gonna be shuffled randomly each time -> producing different train and test sets.
Example:
X_train, X_test, Y_train, Y_test = cross_validation.train_test_split(X, Y, test_size=0.4, random_state=1)