code: function mesh1D(array, level) {
    var zc = zeroCrossings(array, level)
    var n = zc.length
    var npos = new Array(n)
    var ncel = new Array(n)
    for(var i=0; i<n; ++i) {
      npos[i] = [ zc[i] ]
      ncel[i] = [ i ]
    }
    return {
      positions: npos,
      cells: ncel
    }
  }
docs: 1D case: Need to handle specially