|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "fmt" |
| 5 | + "math" |
| 6 | +) |
| 7 | + |
| 8 | +type LogisticRegression struct { |
| 9 | + N int |
| 10 | + n_in int |
| 11 | + n_out int |
| 12 | + W [][]float64 |
| 13 | + b []float64 |
| 14 | +} |
| 15 | + |
| 16 | + |
| 17 | +func LogisticRegression__construct(this *LogisticRegression, N int, n_in int, n_out int) { |
| 18 | + this.N = N |
| 19 | + this.n_in = n_in |
| 20 | + this.n_out = n_out |
| 21 | + |
| 22 | + this.W = make([][]float64, n_out) |
| 23 | + for i := 0; i < n_out; i++ { this.W[i] = make([]float64, n_in) } |
| 24 | + |
| 25 | + this.b = make([]float64, n_out) |
| 26 | +} |
| 27 | + |
| 28 | +func LogisticRegression_train(this *LogisticRegression, x []int, y []int, lr float64) { |
| 29 | + p_y_given_x := make([]float64, this.n_out) |
| 30 | + dy := make([]float64, this.n_out) |
| 31 | + |
| 32 | + for i := 0; i < this.n_out; i++ { |
| 33 | + p_y_given_x[i] = 0 |
| 34 | + for j := 0; j < this.n_in; j++ { |
| 35 | + p_y_given_x[i] += this.W[i][j] * float64(x[j]) |
| 36 | + } |
| 37 | + p_y_given_x[i] += this.b[i] |
| 38 | + } |
| 39 | + LogisticRegression_softmax(this, p_y_given_x) |
| 40 | + |
| 41 | + for i := 0; i < this.n_out; i++ { |
| 42 | + dy[i] = float64(y[i]) - p_y_given_x[i] |
| 43 | + |
| 44 | + for j := 0; j < this.n_in; j++ { |
| 45 | + this.W[i][j] += lr * dy[i] * float64(x[j]) / float64(this.N) |
| 46 | + } |
| 47 | + |
| 48 | + this.b[i] += lr * dy[i] / float64(this.N) |
| 49 | + } |
| 50 | + |
| 51 | +} |
| 52 | + |
| 53 | +func LogisticRegression_softmax(this *LogisticRegression, x []float64) { |
| 54 | + var ( |
| 55 | + max float64 |
| 56 | + sum float64 |
| 57 | + ) |
| 58 | + |
| 59 | + for i := 0; i < this.n_out; i++ { if max < x[i] {max = x[i]} } |
| 60 | + for i := 0; i < this.n_out; i++ { |
| 61 | + x[i] = math.Exp(x[i] - max) |
| 62 | + sum += x[i] |
| 63 | + } |
| 64 | + |
| 65 | + for i := 0; i < this.n_out; i++ { x[i] /= sum } |
| 66 | +} |
| 67 | + |
| 68 | +func LogisticRegression_predict(this *LogisticRegression, x []int, y []float64) { |
| 69 | + for i := 0; i < this.n_out; i++ { |
| 70 | + y[i] = 0 |
| 71 | + for j := 0; j < this.n_in; j++ { |
| 72 | + y[i] += this.W[i][j] * float64(x[j]) |
| 73 | + } |
| 74 | + y[i] += this.b[i] |
| 75 | + } |
| 76 | + |
| 77 | + LogisticRegression_softmax(this, y) |
| 78 | +} |
| 79 | + |
| 80 | + |
| 81 | + |
| 82 | +func test_lr() { |
| 83 | + |
| 84 | + learning_rate := 0.1 |
| 85 | + n_epochs := 500 |
| 86 | + |
| 87 | + train_N := 6 |
| 88 | + test_N := 2 |
| 89 | + n_in := 6 |
| 90 | + n_out := 2 |
| 91 | + |
| 92 | + |
| 93 | + // training data |
| 94 | + train_X := [][]int { |
| 95 | + {1, 1, 1, 0, 0, 0}, |
| 96 | + {1, 0, 1, 0, 0, 0}, |
| 97 | + {1, 1, 1, 0, 0, 0}, |
| 98 | + {0, 0, 1, 1, 1, 0}, |
| 99 | + {0, 0, 1, 1, 0, 0}, |
| 100 | + {0, 0, 1, 1, 1, 0}, |
| 101 | + } |
| 102 | + |
| 103 | + |
| 104 | + train_Y := [][]int { |
| 105 | + {1, 0}, |
| 106 | + {1, 0}, |
| 107 | + {1, 0}, |
| 108 | + {0, 1}, |
| 109 | + {0, 1}, |
| 110 | + {0, 1}, |
| 111 | + } |
| 112 | + |
| 113 | + |
| 114 | + // construct LogisticRegression |
| 115 | + var classifier LogisticRegression |
| 116 | + LogisticRegression__construct(&classifier, train_N, n_in, n_out) |
| 117 | + |
| 118 | + // train |
| 119 | + for epoch := 0; epoch < n_epochs; epoch++ { |
| 120 | + for i := 0; i < train_N; i++ { |
| 121 | + LogisticRegression_train(&classifier, train_X[i], train_Y[i], learning_rate) |
| 122 | + } |
| 123 | + } |
| 124 | + |
| 125 | + // test data |
| 126 | + test_X := [][]int { |
| 127 | + {1, 0, 1, 0, 0, 0}, |
| 128 | + {0, 0, 1, 1, 1, 0}, |
| 129 | + } |
| 130 | + |
| 131 | + test_Y := make([][]float64, test_N) |
| 132 | + for i := 0; i < test_N; i++ { test_Y[i] = make([]float64, n_out) } |
| 133 | + |
| 134 | + |
| 135 | + // test |
| 136 | + for i := 0; i < test_N; i++ { |
| 137 | + LogisticRegression_predict(&classifier, test_X[i], test_Y[i]) |
| 138 | + for j := 0; j < n_out; j++ { |
| 139 | + fmt.Printf("%f ", test_Y[i][j]) |
| 140 | + } |
| 141 | + fmt.Printf("\n") |
| 142 | + } |
| 143 | + |
| 144 | +} |
| 145 | + |
| 146 | + |
| 147 | +func main() { |
| 148 | + test_lr() |
| 149 | +} |
| 150 | + |
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