Try Prof. Willie Wong's code snippet

10 years ago · a31ba88372
parent 97640668bd
commit a31ba88372
1 changed files with 105 additions and 0 deletions
--- a/docs/source/examples/Notebook/Typesetting
+++ b/docs/source/examples/Notebook/Typesetting
@ -7,6 +7,111 @@
    "The Markdown parser included in the Jupyter Notebook is MathJax-aware.  This means that you can freely mix in mathematical expressions using the [MathJax subset of Tex and LaTeX](http://docs.mathjax.org/en/latest/tex.html#tex-support).  [Some examples from the MathJax site](http://www.mathjax.org/demos/tex-samples/) are reproduced below, as well as the Markdown+TeX source."
   ]
  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "\"\"\"Attribution to Willie Wong https://williewong.wordpress.com/2012/07/27/ipython-notebook-take-2/\"\"\"\n",
+    "\n",
+    "from IPython.core.display import *\n",
+    " \n",
+    "def add(x,y): return x+y\n",
+    "def MDPL(string): display(Math(string))\n",
+    "def comp_str(listofstrings): return reduce(add,listofstrings)\n",
+    " \n",
+    "class math_expr(object):\n",
+    "   '''''Math Expression object'''''\n",
+    " \n",
+    "   def __init__(self,atomslist, labeldefault = True, highlight = []):\n",
+    "      '''''init takes arg: list of atoms, each atom being a compilable chunck of LaTeX expression'''''\n",
+    "      self.listofatoms = atomslist\n",
+    "      self.labels = labeldefault\n",
+    "      MDPL(comp_str(self.__colouratoms(highlight)))\n",
+    " \n",
+    "   def _repr_latex_(self):\n",
+    "      '''''Returns a latex expression of the object. Will be parsed by MathJax'''''\n",
+    "      self.__labelatoms()\n",
+    "      latexstring = comp_str(self.labeledatoms) if self.labels else comp_str(self.listofatoms)\n",
+    "      return \"$\" + latexstring + \"$\"\n",
+    " \n",
+    "   @property\n",
+    "   def labeled(self):\n",
+    "      '''''Tells you whether labelling is turned on by default'''''\n",
+    "      return self.labels\n",
+    " \n",
+    "   @labeled.setter\n",
+    "   def label(self,boolean):\n",
+    "      '''''Sets the default labelling'''''\n",
+    "      self.labels = boolean\n",
+    " \n",
+    "   @property\n",
+    "   def latex(self):\n",
+    "      '''''Accesses the LaTeX code snip for the expression'''''\n",
+    "      display(Latex(comp_str(self.listofatoms)))\n",
+    " \n",
+    "   def __labelatoms(self):\n",
+    "      '''''Label atoms by adding underbraces'''''\n",
+    "      self.labeledatoms = [ r\"\\underbrace {\" + self.listofatoms[i] + \"}_{\" + str(i) + \"}\" for i in range(len(self.listofatoms)) ]\n",
+    " \n",
+    "   def replace(self,pos,newstr):\n",
+    "      '''''Replaces an atom with another atom'''''\n",
+    "      MDPL(comp_str(self.__colouratoms([pos])))\n",
+    "      newstrings = list(self.listofatoms)\n",
+    "      newstrings[pos] = newstr\n",
+    "      return math_expr(newstrings,self.labels,[pos])\n",
+    " \n",
+    "   def merge(self,positions):\n",
+    "      '''''Merges atoms: the input is a list of positions. The new atom is placed at the position of the foremost of the positions'''''\n",
+    "      MDPL(comp_str(self.__colouratoms(positions)))\n",
+    "      newstrings = list(self.listofatoms)\n",
+    "      temp = [ newstrings[i] for i in positions ]\n",
+    "      positions.sort()\n",
+    "      positions.reverse()\n",
+    "      for i in positions: del newstrings[i]\n",
+    "      newstrings.insert(positions[-1],comp_str(temp))\n",
+    "      return math_expr(newstrings,self.labels,[positions[-1]])\n",
+    " \n",
+    "   def split(self,pos,newatoms):\n",
+    "      '''''Splits atoms: replaces an atom in place with multiple sub atoms'''''\n",
+    "      MDPL(comp_str(self.__colouratoms([pos])))\n",
+    "      newstrings = list(self.listofatoms)\n",
+    "      del newstrings[pos]\n",
+    "      templen = len(newatoms)\n",
+    "      while len(newatoms) > 0:\n",
+    "         newstrings.insert(pos,newatoms.pop())\n",
+    "      return math_expr(newstrings,self.labels,range(pos,pos+templen))\n",
+    " \n",
+    "   def cancel(self,positions):\n",
+    "      '''''Cancels a bunch of terms: input a list of positions'''''\n",
+    "      MDPL(comp_str(self.__colouratoms(positions)))\n",
+    "      positions.sort()\n",
+    "      positions.reverse()\n",
+    "      newstrings = list(self.listofatoms)\n",
+    "      for i in positions: del newstrings[i]\n",
+    "      return math_expr(newstrings,self.labels)\n",
+    " \n",
+    "   def move(self,posini,posfin):\n",
+    "      '''''Move atom at posini to posfin, pushing all others back'''''\n",
+    "      MDPL(comp_str(self.__colouratoms([posini])))\n",
+    "      newstrings = list(self.listofatoms)\n",
+    "      temp = newstrings.pop(posini)\n",
+    "      newstrings.insert(posfin if posfin < posini else posfin-1, temp)\n",
+    "      return math_expr(newstrings,self.labels,[posfin if posfin < posini else posfin - 1])\n",
+    " \n",
+    "   def __colouratoms(self,positions,labelled=False):\n",
+    "      '''''Returns the list of atoms, but with selected terms coloured'''''\n",
+    "      temp = list(self.listofatoms)\n",
+    "      if labelled:\n",
+    "         self.labelatoms()\n",
+    "         temp = list(self.labeledatoms)\n",
+    "      for i in positions: temp[i] = \"\\color{red}{\"+temp[i]+\"}\"\n",
+    "      return temp\n"
+   ]
+  },
  {
   "cell_type": "markdown",
   "metadata": {},