diff --git a/Week 2/5 Discrete and Fast Fourier Transforms.ipynb b/Week 2/5 Discrete and Fast Fourier Transforms.ipynb index 289d694..c19a0c0 100644 --- a/Week 2/5 Discrete and Fast Fourier Transforms.ipynb +++ b/Week 2/5 Discrete and Fast Fourier Transforms.ipynb @@ -39,7 +39,7 @@ "cell_type": "raw", "metadata": {}, "source": [ - "team_members = \"\"" + "team_members = \"Koen Vendrig, Kees van Kempen\"" ] }, { @@ -66,7 +66,7 @@ }, { "cell_type": "code", - "execution_count": null, + "execution_count": 3, "metadata": { "deletable": false, "nbgrader": { @@ -83,10 +83,7 @@ }, "outputs": [], "source": [ - "# Import packages here ...\n", - "\n", - "# YOUR CODE HERE\n", - "raise NotImplementedError()" + "import numpy as np" ] }, { @@ -121,7 +118,7 @@ }, { "cell_type": "code", - "execution_count": null, + "execution_count": 22, "metadata": { "deletable": false, "nbgrader": { @@ -139,8 +136,31 @@ "outputs": [], "source": [ "def DFT(yk):\n", - " # YOUR CODE HERE\n", - " raise NotImplementedError()" + " N = len(yk)\n", + " x = 2*np.pi*np.arange(N)/N\n", + " beta = yk.T * np.exp(-np.dot(np.arange(N), x)*1j)\n", + " return beta" + ] + }, + { + "cell_type": "code", + "execution_count": 21, + "metadata": {}, + "outputs": [ + { + "data": { + "text/plain": [ + "array([-1.-8.57252759e-16j, -2.-1.71450552e-15j, -7.-6.00076932e-15j,\n", + " -6.-5.14351656e-15j])" + ] + }, + "execution_count": 21, + "metadata": {}, + "output_type": "execute_result" + } + ], + "source": [ + "DFT(np.array([1,2,7,6]))" ] }, { @@ -419,7 +439,7 @@ ], "metadata": { "kernelspec": { - "display_name": "Python 3 (ipykernel)", + "display_name": "Python 3", "language": "python", "name": "python3" },