{"metadata":{"kernelspec":{"language":"python","display_name":"Python 3","name":"python3"},"language_info":{"name":"python","version":"3.12.13","mimetype":"text/x-python","codemirror_mode":{"name":"ipython","version":3},"pygments_lexer":"ipython3","nbconvert_exporter":"python","file_extension":".py"},"kaggle":{"accelerator":"none","dataSources":[],"dockerImageVersionId":28755,"isInternetEnabled":false,"language":"python","sourceType":"notebook","isGpuEnabled":false}},"nbformat_minor":4,"nbformat":4,"cells":[{"cell_type":"code","source":"import numpy as np\nimport pandas as pd\nfrom matplotlib import pyplot as plt\n\ndata = pd.read_csv(\"/kaggle/input/competitions/digit-recognizer/train.csv\")\n","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:50.184482Z","iopub.execute_input":"2026-09-27T09:42:50.184812Z","iopub.status.idle":"2026-09-27T09:42:53.366284Z","shell.execute_reply.started":"2026-09-27T09:42:50.184782Z","shell.execute_reply":"2026-09-27T09:42:53.365071Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"data.head()","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:53.367915Z","iopub.execute_input":"2026-09-27T09:42:53.368282Z","iopub.status.idle":"2026-09-27T09:42:53.408991Z","shell.execute_reply.started":"2026-09-27T09:42:53.368253Z","shell.execute_reply":"2026-09-27T09:42:53.40803Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"data = np.array(data)\nm, n = data.shape\nnp.random.shuffle(data)\n\ndata_dev=data[0:1000].T\nY_dev = data_dev[0]\nX_dev = data_dev[1:n]/ 255.\n\ndata_train = data[1000:m].T\nY_train = data_train[0]\nX_train = data_train[1:n]/ 255.","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:53.410244Z","iopub.execute_input":"2026-09-27T09:42:53.410511Z","iopub.status.idle":"2026-09-27T09:42:54.262962Z","shell.execute_reply.started":"2026-09-27T09:42:53.410487Z","shell.execute_reply":"2026-09-27T09:42:54.261833Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"def init_params():\n    W1 = np.random.rand(10, 784) - 0.5\n    b1 = np.random.rand(10, 1) - 0.5\n    W2 = np.random.rand(10, 10) - 0.5\n    b2 = np.random.rand(10, 1) - 0.5\n    return W1, b1, W2, b2\n\ndef ReLU(Z):\n    return np.maximum(Z, 0)\n\ndef softmax(Z):\n    A = np.exp(Z) / sum(np.exp(Z))\n    return A\n    \ndef forward_prop(W1, b1, W2, b2, X):\n    Z1 = W1.dot(X) + b1\n    A1 = ReLU(Z1)\n    Z2 = W2.dot(A1) + b2\n    A2 = softmax(Z2)\n    return Z1, A1, Z2, A2\n\ndef ReLU_deriv(Z):\n    return Z > 0\n\ndef one_hot(Y):\n    one_hot_Y = np.zeros((Y.size, Y.max() + 1))\n    one_hot_Y[np.arange(Y.size), Y] = 1\n    one_hot_Y = one_hot_Y.T\n    return one_hot_Y\n\ndef backward_prop(Z1, A1, Z2, A2, W1, W2, X, Y):\n    one_hot_Y = one_hot(Y)\n    dZ2 = A2 - one_hot_Y\n    dW2 = 1 / m * dZ2.dot(A1.T)\n    db2 = 1 / m * np.sum(dZ2)\n    dZ1 = W2.T.dot(dZ2) * ReLU_deriv(Z1)\n    dW1 = 1 / m * dZ1.dot(X.T)\n    db1 = 1 / m * np.sum(dZ1)\n    return dW1, db1, dW2, db2\n\ndef update_params(W1, b1, W2, b2, dW1, db1, dW2, db2, alpha):\n    W1 = W1 - alpha * dW1\n    b1 = b1 - alpha * db1    \n    W2 = W2 - alpha * dW2  \n    b2 = b2 - alpha * db2    \n    return W1, b1, W2, b2","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:54.265494Z","iopub.execute_input":"2026-09-27T09:42:54.265809Z","iopub.status.idle":"2026-09-27T09:42:54.277486Z","shell.execute_reply.started":"2026-09-27T09:42:54.265782Z","shell.execute_reply":"2026-09-27T09:42:54.276514Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"def get_predictions(A2):\n    return np.argmax(A2, 0)\n\ndef get_accuracy(predictions, Y):\n    print(predictions, Y)\n    return np.sum(predictions == Y) / Y.size\n\ndef gradient_descent(X, Y, alpha, iterations):\n    W1, b1, W2, b2 = init_params()\n    for i in range(iterations):\n        Z1, A1, Z2, A2 = forward_prop(W1, b1, W2, b2, X)\n        dW1, db1, dW2, db2 = backward_prop(Z1, A1, Z2, A2, W1, W2, X, Y)\n        W1, b1, W2, b2 = update_params(W1, b1, W2, b2, dW1, db1, dW2, db2, alpha)\n        if i % 10 == 0:\n            print(\"Iteration: \", i)\n            predictions = get_predictions(A2)\n            print(get_accuracy(predictions, Y))\n    return W1, b1, W2, b2","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:54.278443Z","iopub.execute_input":"2026-09-27T09:42:54.278737Z","iopub.status.idle":"2026-09-27T09:42:54.306011Z","shell.execute_reply.started":"2026-09-27T09:42:54.278711Z","shell.execute_reply":"2026-09-27T09:42:54.304835Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"W1, b1, W2, b2 = gradient_descent(X_train, Y_train ,0.10, 500)","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:42:54.30717Z","iopub.execute_input":"2026-09-27T09:42:54.307461Z","iopub.status.idle":"2026-09-27T09:43:42.392514Z","shell.execute_reply.started":"2026-09-27T09:42:54.307435Z","shell.execute_reply":"2026-09-27T09:43:42.391823Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"def make_predictions(X, W1, b1, W2, b2):\n    _, _, _, A2 = forward_prop(W1, b1, W2, b2, X)\n    predictions = get_predictions(A2)\n    return predictions\n\ndef test_prediction(index, W1, b1, W2, b2):\n    current_image = X_train[:, index, None]\n    prediction = make_predictions(X_train[:, index, None], W1, b1, W2, b2)\n    label = Y_train[index]\n    print(\"Prediction: \", prediction)\n    print(\"Label: \", label)\n    \n    current_image = current_image.reshape((28, 28)) * 255\n    plt.gray()\n    plt.imshow(current_image, interpolation='nearest')\n    plt.show()","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:43:42.394141Z","iopub.execute_input":"2026-09-27T09:43:42.394481Z","iopub.status.idle":"2026-09-27T09:43:42.402347Z","shell.execute_reply.started":"2026-09-27T09:43:42.394447Z","shell.execute_reply":"2026-09-27T09:43:42.401406Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"test_prediction(0, W1, b1, W2, b2)\ntest_prediction(5, W1, b1, W2, b2)\ntest_prediction(2, W1, b1, W2, b2)\n","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:43:42.403401Z","iopub.execute_input":"2026-09-27T09:43:42.403703Z","iopub.status.idle":"2026-09-27T09:43:42.900247Z","shell.execute_reply.started":"2026-09-27T09:43:42.403673Z","shell.execute_reply":"2026-09-27T09:43:42.899059Z"}},"outputs":[],"execution_count":null},{"cell_type":"code","source":"dev_predictions = make_predictions(X_dev, W1, b1, W2, b2)\nget_accuracy(dev_predictions, Y_dev)","metadata":{"trusted":true,"execution":{"iopub.status.busy":"2026-09-27T09:43:42.901351Z","iopub.execute_input":"2026-09-27T09:43:42.902392Z","iopub.status.idle":"2026-09-27T09:43:42.933475Z","shell.execute_reply.started":"2026-09-27T09:43:42.902356Z","shell.execute_reply":"2026-09-27T09:43:42.932276Z"}},"outputs":[],"execution_count":null}]}