01_Complete Pytorch Tensor(Initializing Tensors, Math, Indexing, Reshaping).ipynb

{"nbformat":4,"nbformat_minor":0,"metadata":{"colab":{"provenance":[],"authorship_tag":"ABX9TyPzsK4HfWzeu9O/JSvLDekL"},"kernelspec":{"name":"python3","display_name":"Python 3"},"language_info":{"name":"python"},"gpuClass":"standard"},"cells":[{"cell_type":"code","execution_count":2,"metadata":{"id":"1OuAVvastLz9","executionInfo":{"status":"ok","timestamp":1680786871930,"user_tz":-360,"elapsed":6443,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"outputs":[],"source":["import torch\n","import numpy as np"]},{"cell_type":"code","source":["device = \"cuda\" if torch.cuda.is_available() else \"cpu\""],"metadata":{"id":"ckq-tcH2uNsd","executionInfo":{"status":"ok","timestamp":1680786871931,"user_tz":-360,"elapsed":30,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":3,"outputs":[]},{"cell_type":"code","source":["my_tensor = torch.tensor([[1,2,3],[4,5,6]], dtype=torch.float32,device=device, requires_grad=True)"],"metadata":{"id":"bnNdrNI9t0NP","executionInfo":{"status":"ok","timestamp":1680786871932,"user_tz":-360,"elapsed":30,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":4,"outputs":[]},{"cell_type":"code","source":["print(my_tensor)\n","print(my_tensor.dtype)\n","print(my_tensor.device)\n","print(my_tensor.shape)\n","print(my_tensor.requires_grad)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"1MjxYWA_ukcw","executionInfo":{"status":"ok","timestamp":1680786871934,"user_tz":-360,"elapsed":30,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"63afd463-2ff5-4360-db34-00cc08cda176"},"execution_count":5,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([[1., 2., 3.],\n","        [4., 5., 6.]], requires_grad=True)\n","torch.float32\n","cpu\n","torch.Size([2, 3])\n","True\n"]}]},{"cell_type":"markdown","source":["**Common Initialization methods**"],"metadata":{"id":"fiG99z_5wma-"}},{"cell_type":"code","source":["x = torch.empty(size=(3,3))\n","x = torch.zeros((3,3))\n","x = torch.rand((3,3))\n","x = torch.ones((3,3))\n","x = torch.eye(5,5)\n","x = torch.arange(start=0, end=5, step=1)\n","x = torch.linspace(start=0.1, end=1, steps=10)\n","x = torch.empty(size=(1,5)).normal_(mean=0,std=1)\n","x = torch.empty(size=(1,5)).uniform_(0,1)\n","x = torch.diag(torch.ones(5))"],"metadata":{"id":"sBFdNZI1vmhA","executionInfo":{"status":"ok","timestamp":1680786871935,"user_tz":-360,"elapsed":24,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":6,"outputs":[]},{"cell_type":"markdown","source":["**How to initialize and convert tensors ti other types (int, float, double)**"],"metadata":{"id":"OQU1jUGWyV9s"}},{"cell_type":"code","source":["tensor = torch.arange(4)\n","print(tensor)\n","print(tensor.bool())\n","print(tensor.short())\n","print(tensor.long())\n","print(tensor.half())\n","print(tensor.float())\n","print(tensor.double())"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"qearKiukyhMR","executionInfo":{"status":"ok","timestamp":1680786871936,"user_tz":-360,"elapsed":24,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"9a201125-4e49-4152-fb10-1cbd74aa5c3c"},"execution_count":7,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([0, 1, 2, 3])\n","tensor([False,  True,  True,  True])\n","tensor([0, 1, 2, 3], dtype=torch.int16)\n","tensor([0, 1, 2, 3])\n","tensor([0., 1., 2., 3.], dtype=torch.float16)\n","tensor([0., 1., 2., 3.])\n","tensor([0., 1., 2., 3.], dtype=torch.float64)\n"]}]},{"cell_type":"markdown","source":["Array to Tensor Conversion"],"metadata":{"id":"NZzh1k9yzsbZ"}},{"cell_type":"code","source":["np_array = np.zeros((5,5))\n","tensor = torch.from_numpy(np_array)\n","np_array_back = tensor.numpy()"],"metadata":{"id":"vYtdXKXGzreO","executionInfo":{"status":"ok","timestamp":1680786871937,"user_tz":-360,"elapsed":18,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":8,"outputs":[]},{"cell_type":"markdown","source":["Tensor Math and Comparison Operations"],"metadata":{"id":"E5Ju1aGy0NXa"}},{"cell_type":"code","source":["x = torch.tensor([1,2,3])\n","y = torch.tensor([9,8,7])\n"],"metadata":{"id":"FKqf1Imf0MhL","executionInfo":{"status":"ok","timestamp":1680786872470,"user_tz":-360,"elapsed":550,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":9,"outputs":[]},{"cell_type":"code","source":["z1 = torch.empty(3)\n","torch.add(x,y,out=z1)\n","z2 = torch.add(x,y)\n","z = x+y\n","z = x-y\n"],"metadata":{"id":"xA2ikq2u2EpE","executionInfo":{"status":"ok","timestamp":1680786872471,"user_tz":-360,"elapsed":55,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":10,"outputs":[]},{"cell_type":"code","source":["z = torch.true_divide(x,y)\n","print(z)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"WiIUbhbL2gbz","executionInfo":{"status":"ok","timestamp":1680786872473,"user_tz":-360,"elapsed":56,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"6b0ee17f-fd61-48c5-b296-e6f7598cb1b8"},"execution_count":11,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([0.1111, 0.2500, 0.4286])\n"]}]},{"cell_type":"code","source":["#Inplace operations\n","t = torch.zeros(3)\n","t.add_(x)\n","t+=x\n","print(t)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"da4UhbXW27YT","executionInfo":{"status":"ok","timestamp":1680786872475,"user_tz":-360,"elapsed":55,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"286c954e-7c46-4bf7-d29d-42c6d5df986b"},"execution_count":12,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([2., 4., 6.])\n"]}]},{"cell_type":"code","source":["z = x.pow(2)\n","z = x**2"],"metadata":{"id":"ui4KxsyZ8bBN","executionInfo":{"status":"ok","timestamp":1680786872477,"user_tz":-360,"elapsed":52,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":13,"outputs":[]},{"cell_type":"markdown","source":["Matrix Multiplication"],"metadata":{"id":"hrwgs1zW8nng"}},{"cell_type":"code","source":["x1 = torch.rand((2,5))\n","x2 = torch.rand((5,3))\n","x3 = torch.mm(x1,x2) #2*3\n","x3 = x1.mm(x2)\n","print(x3)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"jssOqaPg8fw3","executionInfo":{"status":"ok","timestamp":1680786872478,"user_tz":-360,"elapsed":51,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"408922fd-0859-4296-cb06-74659dee7365"},"execution_count":14,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([[1.4890, 1.8544, 1.2055],\n","        [1.6049, 1.6866, 1.2896]])\n"]}]},{"cell_type":"code","source":["#Matrix Exponentiation\n","matrix_exp = torch.rand(5,5)\n","print(matrix_exp.matrix_power(3))"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"mZNgVNhb9Wre","executionInfo":{"status":"ok","timestamp":1680786872482,"user_tz":-360,"elapsed":52,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"35e16b3b-7d0f-48dc-94ae-dfa074837a02"},"execution_count":15,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([[3.7936, 3.6309, 4.6495, 4.7988, 2.5858],\n","        [4.0491, 3.6766, 4.8338, 4.9453, 2.6238],\n","        [2.6356, 2.3673, 3.1040, 3.1732, 1.6803],\n","        [2.7276, 2.6100, 3.3616, 3.4581, 1.8636],\n","        [2.9145, 2.9137, 3.6719, 3.7993, 2.0549]])\n"]}]},{"cell_type":"code","source":["#element wise\n","z = x*y\n","print(z)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"gMxfJOjy9ziG","executionInfo":{"status":"ok","timestamp":1680786872484,"user_tz":-360,"elapsed":48,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"f2696ccd-3210-4c34-9891-0aaba914aa28"},"execution_count":16,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([ 9, 16, 21])\n"]}]},{"cell_type":"code","source":["#dot product\n","z = torch.dot(x,y)\n","print(z)\n","print(x.dot(y))"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"tWqDmWav9_mR","executionInfo":{"status":"ok","timestamp":1680786872485,"user_tz":-360,"elapsed":44,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"99574b82-3727-4623-f3b9-1a883e145ba0"},"execution_count":17,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor(46)\n","tensor(46)\n"]}]},{"cell_type":"markdown","source":["Batch Matrix Multiplication"],"metadata":{"id":"8mVG8Pos-cz4"}},{"cell_type":"code","source":["batch = 32\n","n = 10\n","m = 20\n","p = 30\n","tensor1 = torch.rand((batch, n, m))\n","tensor2 = torch.rand((batch, m, p))\n","out_bmm = torch.bmm(tensor1, tensor2) # (batch, n, p)\n","# print(out_bmm)"],"metadata":{"id":"jE79In3G-gMo","executionInfo":{"status":"ok","timestamp":1680786872487,"user_tz":-360,"elapsed":41,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}}},"execution_count":18,"outputs":[]},{"cell_type":"markdown","source":["Other Useful Tensor Operations "],"metadata":{"id":"g3iZIe7OkgeS"}},{"cell_type":"code","source":["sum_x = torch.sum(x, dim=0)\n","values, indices = torch.max(x, dim=0)\n","values, indices = torch.min(x, dim=0)\n","abs_x = torch.abs(x)\n","z = torch.argmax(x, dim=0)\n","z = torch.argmin(x, dim=0)\n","mean_x = torch.mean(x.float(),dim=0)\n","z = torch.eq(x, y)\n","sorted_y, indices = torch.sort(y, dim=0, descending=False)\n","z = torch.clamp(x, min=0, max=10)\n","\n","x = torch.tensor([1,0,1,1,1], dtype=torch.bool)\n","z = torch.any(x)\n","print(z)\n","z = torch.all(x)\n","print(z)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"vEKNfIJGkq01","executionInfo":{"status":"ok","timestamp":1680786872488,"user_tz":-360,"elapsed":41,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"bff54e23-806a-496a-df04-950c89fb7035"},"execution_count":19,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor(True)\n","tensor(False)\n"]}]},{"cell_type":"markdown","source":["Tensor Indexing"],"metadata":{"id":"9SX8t-YHoUw7"}},{"cell_type":"code","source":["batch_size = 10\n","features  = 25\n","x = torch.rand((batch_size, features))\n","print(x[0].shape)"],"metadata":{"id":"_TNarPkAoXxd","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1680786895948,"user_tz":-360,"elapsed":9,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"32b52392-db0e-4063-af65-ebacffc054b7"},"execution_count":21,"outputs":[{"output_type":"stream","name":"stdout","text":["torch.Size([25])\n"]}]},{"cell_type":"code","source":["print(x[:,0])\n","print(x[2,0:10])\n","x[0,0] = 100"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"RkBu-I9UtWvo","executionInfo":{"status":"ok","timestamp":1680787022253,"user_tz":-360,"elapsed":9,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"da6dc49d-8bc0-46b3-af61-5ad203838582"},"execution_count":25,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([0.6067, 0.3585, 0.4561, 0.2488, 0.8898, 0.8318, 0.2964, 0.5615, 0.3436,\n","        0.6834])\n","tensor([0.4561, 0.5319, 0.0531, 0.9698, 0.8082, 0.4015, 0.5971, 0.6548, 0.3522,\n","        0.3790])\n"]}]},{"cell_type":"markdown","source":["Fancy Indexing"],"metadata":{"id":"6PgTW2kHtxAj"}},{"cell_type":"code","source":["x = torch.arange(10)\n","indices = [2,5,8]\n","print(x[indices])\n","\n","x = torch.rand((3,5))\n","print(x)\n","rows = torch.tensor(([1,0]))\n","cols = torch.tensor((4,0))\n","print(x[rows, cols])"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"XEQZ_sdXtwYI","executionInfo":{"status":"ok","timestamp":1680787286705,"user_tz":-360,"elapsed":7,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"181f13d2-4e60-456a-ebf7-200aa3a19b00"},"execution_count":28,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([2, 5, 8])\n","tensor([[0.4725, 0.3829, 0.5523, 0.2132, 0.7067],\n","        [0.6125, 0.8671, 0.4216, 0.7604, 0.7376],\n","        [0.9168, 0.3681, 0.8886, 0.3290, 0.2316]])\n","tensor([0.7376, 0.4725])\n"]}]},{"cell_type":"markdown","source":["Advance Indexing"],"metadata":{"id":"j8wD5gYnu6k0"}},{"cell_type":"code","source":["x = torch.arange(10)\n","print(x[(x<2) | (x>8)])\n","print(x[x.remainder(2)==0])"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"zc8RdVxxu5xt","executionInfo":{"status":"ok","timestamp":1680787530759,"user_tz":-360,"elapsed":7,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"00022c88-4120-4601-8215-0ddde2996cb3"},"execution_count":30,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([0, 1, 9])\n","tensor([0, 2, 4, 6, 8])\n"]}]},{"cell_type":"code","source":["print(torch.where(x>5,x,x*2))\n","print(x.unique())\n","print(x.ndimension())"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"U20rpXGxv0ff","executionInfo":{"status":"ok","timestamp":1680787820816,"user_tz":-360,"elapsed":8,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"ff662018-833a-4cbb-cd32-9d10478b2637"},"execution_count":33,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([ 0,  2,  4,  6,  8, 10,  6,  7,  8,  9])\n","tensor([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])\n","1\n"]}]},{"cell_type":"code","source":["print(x.numel())"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"5DFC7rAdwzmz","executionInfo":{"status":"ok","timestamp":1680787859036,"user_tz":-360,"elapsed":605,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"9efc2a83-526c-4d9d-d916-9146a08fa0da"},"execution_count":34,"outputs":[{"output_type":"stream","name":"stdout","text":["10\n"]}]},{"cell_type":"markdown","source":["# Tensor Reshaping"],"metadata":{"id":"lVOBpwLOw_V-"}},{"cell_type":"code","source":["x = torch.arange(9)\n","x_3x3 = x.view(3,3) # It needs contigious memory allocation\n","print(x_3x3)\n","x_3x3 = x.reshape(3,3)\n","y = x_3x3.t()\n","# print(y.view(9)) This is not possible because after transpose memory are not contigious\n","print(y.contiguous().view(9))"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"L8iwNDxLxC51","executionInfo":{"status":"ok","timestamp":1680788311549,"user_tz":-360,"elapsed":375,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"df403320-7bda-4c6f-acc0-b52c4576652c"},"execution_count":39,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([[0, 1, 2],\n","        [3, 4, 5],\n","        [6, 7, 8]])\n","tensor([0, 3, 6, 1, 4, 7, 2, 5, 8])\n"]}]},{"cell_type":"code","source":["x1 = torch.rand((2,5))\n","x2 = torch.rand((2,5))\n","print(torch.cat((x1,x2), dim=0))  # row number will be increased\n","print(torch.cat((x1,x2),dim=1))   ## coloumn number will be increased"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"8OTMau3_yz8e","executionInfo":{"status":"ok","timestamp":1680788557077,"user_tz":-360,"elapsed":1719,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"8175a874-9d7a-4345-f5ba-cb67eb88c745"},"execution_count":42,"outputs":[{"output_type":"stream","name":"stdout","text":["tensor([[0.8880, 0.1400, 0.2813, 0.5351, 0.3915],\n","        [0.7584, 0.2716, 0.2698, 0.0819, 0.2846],\n","        [0.2387, 0.1721, 0.9608, 0.3478, 0.6290],\n","        [0.0448, 0.0213, 0.5642, 0.7893, 0.5633]])\n","tensor([[0.8880, 0.1400, 0.2813, 0.5351, 0.3915, 0.2387, 0.1721, 0.9608, 0.3478,\n","         0.6290],\n","        [0.7584, 0.2716, 0.2698, 0.0819, 0.2846, 0.0448, 0.0213, 0.5642, 0.7893,\n","         0.5633]])\n"]}]},{"cell_type":"code","source":["z = x1.view(-1)\n","print(z.shape)\n"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"XeME9rdEzyhk","executionInfo":{"status":"ok","timestamp":1680788659582,"user_tz":-360,"elapsed":8,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"79fd078f-b5f7-4fff-d16a-4f977bd3654c"},"execution_count":43,"outputs":[{"output_type":"stream","name":"stdout","text":["torch.Size([10])\n"]}]},{"cell_type":"code","source":["batch = 64\n","x = torch.rand((batch, 2, 5))\n","z = x.view(batch,-1)\n","print(z.shape)\n"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"ukYMz3OQz8LA","executionInfo":{"status":"ok","timestamp":1680788723109,"user_tz":-360,"elapsed":7,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"c66a0df4-a5fb-470c-f013-326a75762c09"},"execution_count":44,"outputs":[{"output_type":"stream","name":"stdout","text":["torch.Size([64, 10])\n"]}]},{"cell_type":"code","source":["z = x.permute(0,2,1)  # transpose is a special version of permute\n","print(z.shape)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"Yfitw4-00N_u","executionInfo":{"status":"ok","timestamp":1680788828905,"user_tz":-360,"elapsed":393,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"872a4635-7dba-4d54-dc4b-b3772232f0bb"},"execution_count":45,"outputs":[{"output_type":"stream","name":"stdout","text":["torch.Size([64, 5, 2])\n"]}]},{"cell_type":"code","source":["x = torch.arange(10)\n","print(x.unsqueeze(0).shape)\n","print(x.unsqueeze(1).shape)\n","x = torch.arange(10).unsqueeze(0).unsqueeze(1)\n","print(x)"],"metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"_ooF30EQ1Omw","executionInfo":{"status":"ok","timestamp":1680789342175,"user_tz":-360,"elapsed":7,"user":{"displayName":"Mozammal Hossain","userId":"08092702458570765823"}},"outputId":"b3fe8123-a56e-4afd-8afc-9a13b5a7e801"},"execution_count":52,"outputs":[{"output_type":"stream","name":"stdout","text":["torch.Size([1, 10])\n","torch.Size([10, 1])\n","tensor([[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]]])\n"]}]}]}