Add example

Author: martinRenou

examples/binary_image.ipynb

@@ -0,0 +1,100 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Draw a NumPy array directly on the Canvas with `put_image_data`"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import numpy as np\n",
+    "from ipycanvas import Canvas, hold_canvas"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "dx, dy = 0.01, 0.01\n",
+    "\n",
+    "y, x = np.mgrid[slice(1, 5 + dy, dy),\n",
+    "                slice(1, 5 + dx, dx)]\n",
+    "\n",
+    "z = np.sin(x)**5 + np.cos(5 + y*x) * np.cos(x)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "min = np.min(z)\n",
+    "max = np.max(z)\n",
+    "\n",
+    "def scale(value):\n",
+    "    scaled_value = (value - min) / (max - min) \n",
+    "    return 255 if value > max else scaled_value * 255\n",
+    "\n",
+    "vecscale = np.vectorize(scale)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "zz = np.stack((np.zeros_like(z), vecscale(z), vecscale(z)), axis=2)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "canvas = Canvas(size=(zz.shape[0], zz.shape[1]))\n",
+    "canvas"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "canvas.put_image_data(zz, 0, 0)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.7.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}