code: function(rhs) {
              var n = rhs.length;
              // `x` is a solution vector.
              var x = [];
              var tmp = [];
              var b = 2.0;
              
              x[0] = rhs[0] / b;
              // Decomposition and forward substitution.
              for (var i = 1; i < n; i++) { 
  	        tmp[i] = 1 / b;
  	        b = (i < n - 1 ? 4.0 : 3.5) - tmp[i];
  	        x[i] = (rhs[i] - x[i - 1]) / b;
              }
              for (i = 1; i < n; i++) {
                  // Backsubstitution.
  	        x[n - i - 1] -= tmp[n - i] * x[n - i]; 
              }
              return x;
          }
docs: Solves a tridiagonal system for one of coordinates (x or y) of first Bezier control points. @param rhs Right hand side vector. @return Solution vector.