align_concat.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<xarray.DataArray (x: 2, y: 2)>\n",
       "array([[1, 1],\n",
       "       [1, 1]])\n",
       "Coordinates:\n",
       "  * x        (x) <U2 'x1' 'x2'\n",
       "  * y        (y) <U2 'y1' 'y2'"
      ]
     },
     "execution_count": 39,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import xarray\n",
    "a = xarray.DataArray(\n",
    "    [[1,1], [1,1]],\n",
    "    dims=['x', 'y'],\n",
    "    coords={'x': ['x1', 'x2'], 'y': ['y1', 'y2']})\n",
    "a"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<xarray.DataArray (x: 2, y: 2)>\n",
       "array([[1, 1],\n",
       "       [1, 1]])\n",
       "Coordinates:\n",
       "  * x        (x) <U2 'x2' 'x1'\n",
       "  * y        (y) <U2 'y3' 'y4'"
      ]
     },
     "execution_count": 40,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "b = xarray.DataArray(\n",
    "    [[1,1], [1,1]],\n",
    "    dims=['x', 'y'],\n",
    "    coords={'x': ['x2', 'x1'], 'y': ['y3', 'y4']})\n",
    "b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "ename": "ValueError",
     "evalue": "the variable 'x' has the same name as one of its dimensions ('y', 'x'), but it is not 1-dimensional and thus it is not a valid index",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mValueError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-41-2a3d8764336f>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mxarray\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mconcat\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m[\u001b[0m\u001b[0ma\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mb\u001b[0m\u001b[1;33m]\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mdim\u001b[0m\u001b[1;33m=\u001b[0m\u001b[1;34m'y'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\combine.py\u001b[0m in \u001b[0;36mconcat\u001b[1;34m(objs, dim, data_vars, coords, compat, positions, indexers, mode, concat_over)\u001b[0m\n\u001b[0;32m    112\u001b[0m         raise TypeError('can only concatenate xarray Dataset and DataArray '\n\u001b[0;32m    113\u001b[0m                         'objects, got %s' % type(first_obj))\n\u001b[1;32m--> 114\u001b[1;33m     \u001b[1;32mreturn\u001b[0m \u001b[0mf\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mobjs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mdim\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mdata_vars\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcoords\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcompat\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mpositions\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    115\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    116\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\combine.py\u001b[0m in \u001b[0;36m_dataarray_concat\u001b[1;34m(arrays, dim, data_vars, coords, compat, positions)\u001b[0m\n\u001b[0;32m    299\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    300\u001b[0m     ds = _dataset_concat(datasets, dim, data_vars, coords, compat,\n\u001b[1;32m--> 301\u001b[1;33m                          positions)\n\u001b[0m\u001b[0;32m    302\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0marrays\u001b[0m\u001b[1;33m[\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m]\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0m_from_temp_dataset\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mds\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mname\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    303\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\combine.py\u001b[0m in \u001b[0;36m_dataset_concat\u001b[1;34m(datasets, dim, data_vars, coords, compat, positions)\u001b[0m\n\u001b[0;32m    269\u001b[0m         \u001b[0minsert_result_variable\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mk\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcombined\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    270\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 271\u001b[1;33m     \u001b[0mresult\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mDataset\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mresult_vars\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mattrs\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mresult_attrs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    272\u001b[0m     \u001b[0mresult\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mresult\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mset_coords\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mresult_coord_names\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    273\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\dataset.py\u001b[0m in \u001b[0;36m__init__\u001b[1;34m(self, data_vars, coords, attrs, compat, **kwargs)\u001b[0m\n\u001b[0;32m    207\u001b[0m             \u001b[0mcoords\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mset\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    208\u001b[0m         \u001b[1;32mif\u001b[0m \u001b[0mdata_vars\u001b[0m \u001b[1;32mis\u001b[0m \u001b[1;32mnot\u001b[0m \u001b[1;32mNone\u001b[0m \u001b[1;32mor\u001b[0m \u001b[0mcoords\u001b[0m \u001b[1;32mis\u001b[0m \u001b[1;32mnot\u001b[0m \u001b[1;32mNone\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 209\u001b[1;33m             \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0m_set_init_vars_and_dims\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mdata_vars\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcoords\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcompat\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    210\u001b[0m         \u001b[1;32mif\u001b[0m \u001b[0mattrs\u001b[0m \u001b[1;32mis\u001b[0m \u001b[1;32mnot\u001b[0m \u001b[1;32mNone\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    211\u001b[0m             \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mattrs\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mattrs\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\dataset.py\u001b[0m in \u001b[0;36m_set_init_vars_and_dims\u001b[1;34m(self, vars, coords, compat)\u001b[0m\n\u001b[0;32m    263\u001b[0m         \u001b[0maligned\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0malign_variables\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mvariables\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    264\u001b[0m         new_variables, new_coord_names = expand_variables(aligned,\n\u001b[1;32m--> 265\u001b[1;33m                                                           compat=compat)\n\u001b[0m\u001b[0;32m    266\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    267\u001b[0m         \u001b[0mnew_coord_names\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mupdate\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mcoords\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\merge.py\u001b[0m in \u001b[0;36mexpand_variables\u001b[1;34m(raw_variables, old_variables, compat)\u001b[0m\n\u001b[0;32m     75\u001b[0m                     \u001b[0madd_variable\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mdim\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mcoord\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mvariable\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     76\u001b[0m             \u001b[0mvar\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mvariable\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 77\u001b[1;33m         \u001b[0madd_variable\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mname\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     78\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     79\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mnew_variables\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mnew_coord_names\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\merge.py\u001b[0m in \u001b[0;36madd_variable\u001b[1;34m(name, var)\u001b[0m\n\u001b[0;32m     55\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     56\u001b[0m     \u001b[1;32mdef\u001b[0m \u001b[0madd_variable\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mname\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 57\u001b[1;33m         \u001b[0mvar\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0m_as_dataset_variable\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mname\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     58\u001b[0m         \u001b[1;32mif\u001b[0m \u001b[0mname\u001b[0m \u001b[1;32mnot\u001b[0m \u001b[1;32min\u001b[0m \u001b[0mvariables\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     59\u001b[0m             \u001b[0mvariables\u001b[0m\u001b[1;33m[\u001b[0m\u001b[0mname\u001b[0m\u001b[1;33m]\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32mC:\\Users\\crusader\\Anaconda3\\lib\\site-packages\\xarray\\core\\merge.py\u001b[0m in \u001b[0;36m_as_dataset_variable\u001b[1;34m(name, var)\u001b[0m\n\u001b[0;32m     18\u001b[0m             raise ValueError('the variable %r has the same name as one of its '\n\u001b[0;32m     19\u001b[0m                              \u001b[1;34m'dimensions %r, but it is not 1-dimensional and '\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 20\u001b[1;33m                              'thus it is not a valid index' % (name, var.dims))\n\u001b[0m\u001b[0;32m     21\u001b[0m         \u001b[0mvar\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mto_coord\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     22\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mvar\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mValueError\u001b[0m: the variable 'x' has the same name as one of its dimensions ('y', 'x'), but it is not 1-dimensional and thus it is not a valid index"
     ]
    }
   ],
   "source": [
    "xarray.concat([a, b], dim='y')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(<xarray.DataArray (x: 2, y: 4)>\n",
       " array([[  1.,   1.,  nan,  nan],\n",
       "        [  1.,   1.,  nan,  nan]])\n",
       " Coordinates:\n",
       "   * x        (x) object 'x1' 'x2'\n",
       "   * y        (y) object 'y1' 'y2' 'y3' 'y4', <xarray.DataArray (x: 2, y: 4)>\n",
       " array([[ nan,  nan,   1.,   1.],\n",
       "        [ nan,  nan,   1.,   1.]])\n",
       " Coordinates:\n",
       "   * x        (x) object 'x1' 'x2'\n",
       "   * y        (y) object 'y1' 'y2' 'y3' 'y4')"
      ]
     },
     "execution_count": 42,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a1, b1 = xarray.align(a, b, join='outer')\n",
    "a1, b1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<xarray.DataArray (x: 2, y: 8)>\n",
       "array([[  1.,   1.,  nan,  nan,  nan,  nan,   1.,   1.],\n",
       "       [  1.,   1.,  nan,  nan,  nan,  nan,   1.,   1.]])\n",
       "Coordinates:\n",
       "  * x        (x) object 'x1' 'x2'\n",
       "  * y        (y) object 'y1' 'y2' 'y3' 'y4' 'y1' 'y2' 'y3' 'y4'"
      ]
     },
     "execution_count": 43,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "xarray.concat([a1, b1], dim='y')"
   ]
  }
 ],
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