init - 初始化项目

samples/python/tutorial_code/ml/non_linear_svms/non_linear_svms.py

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+from __future__ import print_function
+import cv2 as cv
+import numpy as np
+import random as rng
+
+NTRAINING_SAMPLES = 100 # Number of training samples per class
+FRAC_LINEAR_SEP = 0.9   # Fraction of samples which compose the linear separable part
+
+# Data for visual representation
+WIDTH = 512
+HEIGHT = 512
+I = np.zeros((HEIGHT, WIDTH, 3), dtype=np.uint8)
+
+# --------------------- 1. Set up training data randomly ---------------------------------------
+trainData = np.empty((2*NTRAINING_SAMPLES, 2), dtype=np.float32)
+labels = np.empty((2*NTRAINING_SAMPLES, 1), dtype=np.int32)
+
+rng.seed(100) # Random value generation class
+
+# Set up the linearly separable part of the training data
+nLinearSamples = int(FRAC_LINEAR_SEP * NTRAINING_SAMPLES)
+
+## [setup1]
+# Generate random points for the class 1
+trainClass = trainData[0:nLinearSamples,:]
+# The x coordinate of the points is in [0, 0.4)
+c = trainClass[:,0:1]
+c[:] = np.random.uniform(0.0, 0.4 * WIDTH, c.shape)
+# The y coordinate of the points is in [0, 1)
+c = trainClass[:,1:2]
+c[:] = np.random.uniform(0.0, HEIGHT, c.shape)
+
+# Generate random points for the class 2
+trainClass = trainData[2*NTRAINING_SAMPLES-nLinearSamples:2*NTRAINING_SAMPLES,:]
+# The x coordinate of the points is in [0.6, 1]
+c = trainClass[:,0:1]
+c[:] = np.random.uniform(0.6*WIDTH, WIDTH, c.shape)
+# The y coordinate of the points is in [0, 1)
+c = trainClass[:,1:2]
+c[:] = np.random.uniform(0.0, HEIGHT, c.shape)
+## [setup1]
+
+#------------------ Set up the non-linearly separable part of the training data ---------------
+## [setup2]
+# Generate random points for the classes 1 and 2
+trainClass = trainData[nLinearSamples:2*NTRAINING_SAMPLES-nLinearSamples,:]
+# The x coordinate of the points is in [0.4, 0.6)
+c = trainClass[:,0:1]
+c[:] = np.random.uniform(0.4*WIDTH, 0.6*WIDTH, c.shape)
+# The y coordinate of the points is in [0, 1)
+c = trainClass[:,1:2]
+c[:] = np.random.uniform(0.0, HEIGHT, c.shape)
+## [setup2]
+
+#------------------------- Set up the labels for the classes ---------------------------------
+labels[0:NTRAINING_SAMPLES,:] = 1                   # Class 1
+labels[NTRAINING_SAMPLES:2*NTRAINING_SAMPLES,:] = 2 # Class 2
+
+#------------------------ 2. Set up the support vector machines parameters --------------------
+print('Starting training process')
+## [init]
+svm = cv.ml.SVM_create()
+svm.setType(cv.ml.SVM_C_SVC)
+svm.setC(0.1)
+svm.setKernel(cv.ml.SVM_LINEAR)
+svm.setTermCriteria((cv.TERM_CRITERIA_MAX_ITER, int(1e7), 1e-6))
+## [init]
+
+#------------------------ 3. Train the svm ----------------------------------------------------
+## [train]
+svm.train(trainData, cv.ml.ROW_SAMPLE, labels)
+## [train]
+print('Finished training process')
+
+#------------------------ 4. Show the decision regions ----------------------------------------
+## [show]
+green = (0,100,0)
+blue = (100,0,0)
+for i in range(I.shape[0]):
+    for j in range(I.shape[1]):
+        sampleMat = np.matrix([[j,i]], dtype=np.float32)
+        response = svm.predict(sampleMat)[1]
+
+        if response == 1:
+            I[i,j] = green
+        elif response == 2:
+            I[i,j] = blue
+## [show]
+
+#----------------------- 5. Show the training data --------------------------------------------
+## [show_data]
+thick = -1
+# Class 1
+for i in range(NTRAINING_SAMPLES):
+    px = trainData[i,0]
+    py = trainData[i,1]
+    cv.circle(I, (int(px), int(py)), 3, (0, 255, 0), thick)
+
+# Class 2
+for i in range(NTRAINING_SAMPLES, 2*NTRAINING_SAMPLES):
+    px = trainData[i,0]
+    py = trainData[i,1]
+    cv.circle(I, (int(px), int(py)), 3, (255, 0, 0), thick)
+## [show_data]
+
+#------------------------- 6. Show support vectors --------------------------------------------
+## [show_vectors]
+thick = 2
+sv = svm.getUncompressedSupportVectors()
+
+for i in range(sv.shape[0]):
+    cv.circle(I, (int(sv[i,0]), int(sv[i,1])), 6, (128, 128, 128), thick)
+## [show_vectors]
+
+cv.imwrite('result.png', I)                      # save the Image
+cv.imshow('SVM for Non-Linear Training Data', I) # show it to the user
+cv.waitKey()