Machine learning is a subfield of artificial intelligence, which is learning algorithms to make decision-based on those data and try to behave like a human being. It is now growing one of the top five in-demand technologies of 2018. Iris data set is the famous smaller databases for easier visualization and analysis techniques. In this article, we will see a quick view of how to develop machine learning “hello world program”.
2.2.1 Preview data
Let’s, look at the iris flowers numerical data belongs to their four species. You can see a first 15 numerical row of species. If the dataset contains three types of flower sets called Iris virginica, Versicolor and iris Sentosa. These three flower features are measured along with their species.
2.2.2 Description of dataset
Let’s look at a summary of each iris instance attributes.
If the four features of iris species measured by count, min, mean, max, and percentiles.
2.2.3 Description of class
Now, the time to view how many instances the data frame contains.
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- print(iris.groupby('iris').size())
If the dataset contains three classes with 150 instances and its entire instances were measured as numerical values by their features.
2.2.4 Shape of Data
The shape property provides us to seek entire counts of flower instances.
There is a data frame contains 150 samples under the 5 columns.
3. Data visualization
- The visualization techniques provide imagery representation of Iris species and feature It is used to determine correlations between the X and Y variables (dependent and independent variables).
- Now, we are going to visualize the dataset in two ways such as Boxplot, and pairwise joint plot distribution (scatter plot).
3.1 Boxplot
- The graph represented the shape of data distribution and their upper and lower quartiles.
- The iris species might show with few box plot standard ways such as mean, median, and deviation.
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- plt.figure(figsize=(15,10))
- plt.subplot(2,2,1)
- sns.boxplot(x='iris',y='sepallength',data=iris)
- plt.subplot(2,2,2)
- sns.boxplot(x='iris',y='sepalwidth',data=iris)
- plt.subplot(2,2,3)
- sns.boxplot(x='iris',y='petallength',data=iris)
- plt.subplot(2,2,4)
- sns.boxplot(x='iris',y='petalwidth',data=iris)
3.2 Pair plot
The pair plot used to figure out a distribution of single variables and the relationship between two variables. If the pair plot is given a solution for that as a clear understanding of each flower sets at a single graph. Each flower scatters plots represented in different colors.
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- sns.pairplot(iris, hue='iris', size=3, diag_kind="kde")
- sns.pairplot(iris,hue='iris')
Here, it also appears some overleaping data points.
4. Train and validate data (Machine learning)
Here, we’ll separate the dataset into two parts for validation processes such as train data and test data. Then allocating 80% of data for training tasks and the remainder 20% for validation purposes.
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- array = iris.values
- X = array[:,0:4]
- Y = array[:,4]
- validation_size = 0.20
- seed = 7
- X_train, X_validation, Y_train, Y_validation = cross_validation.train_test_split(X, Y, test_size=validation_size,
- random_state=seed)
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- num_folds = 10
- num_instances = len(X_train)
- seed = 7
- scoring = 'accuracy'
4.1 Train the model (Modeling)
- Now, it's time to determine the best suitable algorithm for getting effective accuracy.
- Here, we are going to evaluate five famous frequently used algorithms such as
- Linear regression algorithm
- Logistic regression
- Decision tree classifier
- Gaussian Naïve Base
- Support Vector Machine
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- models = []
- models.append(('LR', LogisticRegression()))
- models.append(('LDA', LinearDiscriminantAnalysis()))
- models.append(('CART', DecisionTreeClassifier()))
- models.append(('NB', GaussianNB()))
- models.append(('SVM', SVM()))
-
- results = []
- names = []
- for name, model in models:
- kfold = cross_validation.KFold(n=num_instances, n_folds=num_folds, random_state=seed)
- cv_results = cross_validation.cross_val_score(model, X_train, Y_train, cv=kfold, scoring=scoring)
- results.append(cv_results)
- names.append(name)
- msg = "%s: %f (%f)" % (name, cv_results.mean(), cv_results.std())
- print(msg)
The support vector machine model appears a high score of accuracy.
4.2 Algorithm comparison
You can also discover better accuracy by the algorithm comparison graph.
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- plt.figure(figsize=(15,10))
- fig = plt.figure()
- fig.suptitle('Differentiate algorithms')
- ax = fig.add_subplot(111)
- plt.boxplot(results)
- ax.set_xticklabels(names)
- plt.show()
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5. Validate the data(prediction)
Let’s predict a value by validation.
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- svn = SVM()
- svn.fit(X_train, Y_train)
- predictions = svn.predict(X_validation)
- print(accuracy_score(Y_validation, predictions))
- print(confusion_matrix(Y_validation, predictions))
- print(classification_report(Y_validation, predictions))
Testing the new data.
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- X_new = numpy.array([[3, 2, 4, 0.2], [ 4.7, 3, 1.3, 0.2 ]])
- print("X_new.shape: {}".format(X_new.shape))
Validating the prediction
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- prediction = svn.predict(X_new)
- print("Prediction of Species: {}".format(prediction))
IV. Summary
I hope, this machine learning a quick demonstration you understood very well.