code: function (coeffs, aziElev) {
      
      var aziElevR = aziElev;
      var N = Math.sqrt(coeffs.length)-1;
      // SH sampling matrix
      var Y_N = computeRealSH(N, aziElev);
      // reconstruction
      var data = numeric.dotVM(coeffs, Y_N);
      // gather in data matrix
      for (var i=0; i<aziElev.length; i++) {
          aziElevR[i][2] = data[i];
      }
      return aziElevR;
  }
docs: inverseSHT implements the inverse SHT from SH coefficients