XY=[ 
 1.3393    3.2455;     -1.2786   22.4212;     -2.5529    9.0218;
 5.0122   18.8167;      3.4174   10.8772;      1.4918   17.7334;
 0.6244   -2.3164;      2.4482   18.5774;     -0.8224    4.0931;
 5.1112   22.7087;     -2.3399   15.1236;      3.2268   11.5728;
 6.1239   -9.1789;     -3.3490   -5.5905;      0.6507   -2.6660]
