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    {
      "cell_type": "code",
      "execution_count": null,
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      "source": [
        "%matplotlib inline"
      ]
    },
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      "source": [
        "\n# Comparison of a Spectrogram and a Reassigned Spectrogram\n\nThis example compares the spectrogram and the reassigned spectrogram of a\nhybrid signal (containing sinusoidal, constant and linear frequency\nmodulations), against its ideal time-frequency characteristics.\n\nFigure 4.34 from the tutorial.\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "from tftb.generators import fmsin, fmhyp\nfrom tftb.processing import ideal_tfr, reassigned_spectrogram, Spectrogram\nimport numpy as np\nimport matplotlib.pyplot as plt\n\nn_points = 128\nsig1, if1 = fmsin(n_points, 0.15, 0.45, 100, 1, 0.4, -1)\nsig2, if2 = fmhyp(n_points, [1, .5], [32, 0.05])\nsig = sig1 + sig2\nideal, t, f = ideal_tfr(np.vstack((if1, if2)))\n_, re_spec, _ = reassigned_spectrogram(sig)\nspec, t3, f3 = Spectrogram(sig).run()\n\n# Ideal tfr\nplt.subplot(221)\nplt.contour(t, f, ideal, 1)\nplt.grid(True)\nplt.gca().set_xticklabels([])\nplt.title(\"Ideal time-frequency distro\")\nplt.ylabel('Normalized Frequency')\n\n# Spectrogram\nplt.subplot(222)\nplt.contour(t3, f3[:64], spec[:64, :])\nplt.grid(True)\nplt.gca().set_xticklabels([])\nplt.title(\"Spectrogram\")\n\n# Reassigned Spectrogram\nplt.subplot(212)\nf = np.linspace(0, 0.5, 64)\nplt.contour(np.arange(128), f, re_spec[:64, :])\nplt.grid(True)\nplt.title(\"Reassigned Spectrogram\")\nplt.xlabel('Time')\nplt.ylabel('Normalized Frequency')\n\nplt.show()"
      ]
    }
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