tutorial3_dwt2D.ipynb

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      "[[2. 2.]\n",
      " [2. 2.]]\n",
      "[[0. 0.]\n",
      " [0. 0.]]\n"
     ]
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   "source": [
    "import numpy as np\n",
    "import pywt\n",
    "\n",
    "\"\"\"单级(阶)离散小波变换\"\"\"\n",
    "\n",
    "data = np.ones((4,4), dtype=np.float64)\n",
    "coeffs = pywt.dwt2(data, 'haar')\n",
    "cA, (cH, cV, cD) = coeffs\n",
    "print(cA)\n",
    "print(cV)"
   ]
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      "[-0.70710678 -0.70710678 -0.70710678 -0.70710678]\n",
      "[-2. -2.]\n",
      "[ 5. 13.]\n"
     ]
    }
   ],
   "source": [
    "from pywt import wavedec\n",
    "import numpy as np\n",
    "\n",
    "\"\"\"多级(阶)离散小波变换\"\"\"\n",
    "\n",
    "coeffs = wavedec([1,2,3,4,5,6,7,8], 'db1', level=2)\n",
    "cA2, cD2, cD1 = coeffs\n",
    "print(cD1)\n",
    "print(cD2)\n",
    "print(cA2)"
   ]
  },
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   "execution_count": null,
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   "source": []
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