Hi, I have a big Problem, I have experimental points which can be describe by a complex function. I can get data points of the real part and of the imaginary partof the function: REAL PART: [0.1000000000e-1, 5.1328], [0.2000000000e-1, 5.1295], [0.4000000000e-1, 5.1246], [0.8000000000e-1, 5.1207], [.1600000000, 5.1135], [.3200000000, 5.1031], [.6400000000, 5.0936], [1.280000000, 5.081], [2.560000000, 5.0688], [5.120000000, 5.0582], [10.24000000, 5.0481], [20.48000000, 5.038], [40.96000000, 5.0281], [81.92000000, 5.0174], [163.8400000, 5.0051], [327.6800000, 4.9908], [655.3600000, 4.9733], [1310.700000, 4.9518], [2621.400000, 4.9254], [5242.900000, 4.8927], [10486.00000, 4.8534], [20972.00000, 4.8077], [41943.00000, 4.7539], [83886.00000, 4.6957], [167770.0000, 4.6343], [335540.0000, 4.5702], [671090.0000, 4.5076], [1342200.000, 4.4478], [2684400.000, 4.3949], [5368700.000, 4.3688], [10000000.00, 4.288]