code: public double[] postConvert(double[] X) {
  		if (X.length != standardN) {
  			throw new IllegalArgumentException("wrong array dimension: " + X.length);
  		}
  		double[] ret = new double[originalN];
  		int cntSplitted = 0;
  		for (int i = standardS; i < standardN; i++) {
  			if (splittedVariablesList.contains(i - standardS)) {
  				// this variable was splitted: x = xPlus-xMinus
  				ret[i - standardS] = X[i] - X[standardN + cntSplitted];
  				cntSplitted++;
  			} else {
  				ret[i - standardS] = X[i];
  			}
  		}
  		// this.postconvertedX = ret;
  		return ret;
  	}
docs: Get back the vector in the original components.
  @param X vector in the standard variables
  @return the original component