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   "source": [
    "#### **Title**: Multiple selection streams example\n",
    "\n",
    "**Description**: A linked streams example demonstrating how to use multiple Selection1D streams on separate Points objects.\n",
    "\n",
    "**Dependencies**: Bokeh\n",
    "\n",
    "**Backends**: [Bokeh](./Selection1D_paired.ipynb), [Plotly](../plotly/Selection1D_paired.ipynb)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "import holoviews as hv\n",
    "from holoviews import opts, streams\n",
    "\n",
    "hv.extension('bokeh')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Declare two sets of points generated from multivariate distribution\n",
    "points = hv.Points(np.random.multivariate_normal((0, 0), [[1, 0.1], [0.1, 1]], (1000,)))\n",
    "points2 = hv.Points(np.random.multivariate_normal((3, 3), [[1, 0.1], [0.1, 1]], (1000,)))\n",
    "\n",
    "# Declare two selection streams and set points and points2 as the source of each\n",
    "sel1 = streams.Selection1D(source=points)\n",
    "sel2 = streams.Selection1D(source=points2)\n",
    "\n",
    "# Declare DynamicMaps to show mean y-value of selection as HLine\n",
    "hline1 = hv.DynamicMap(lambda index: hv.HLine(points['y'][index].mean() if index else -10), streams=[sel1])\n",
    "hline2 = hv.DynamicMap(lambda index: hv.HLine(points2['y'][index].mean() if index else -10), streams=[sel2])\n",
    "\n",
    "# Combine points and dynamic HLines\n",
    "(points * points2 * hline1 * hline2).opts(\n",
    "    opts.Points(active_tools=['box_select', 'tap'], height=400,\n",
    "                tools=['box_select', 'lasso_select', 'tap'], width=400))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<center><img src=\"https://assets.holoviews.org/gifs/examples/streams/bokeh/multiple_selection.gif\" width=350></center>"
   ]
  }
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