code: public static double[] yVals(double[] vector) {
          double[] y = new double[vector.length / 2];
          int count = 0;
          for (int i = 0; i < vector.length; i++) {
              if (i % 2 == 0)
                  y[count++] = vector[i];
          }
          return y;
      }
docs: This returns the odd indexed values for the given vector
  @param vector the odd indexed values of rht egiven vector
  @return the y values of the given vector