{ std::vector meas_counts={4., 3., 3., 1., 5., 2., 3., 1., 2., 3., 1., 7., 4., 1., 1., 2., 2., 4., 3., 1., 2., 1., 0., 5., 4., 2., 3., 2., 0., 1., 2., 6., 1., 3., 5., 3., 0., 2., 2., 1., 3., 6., 1., 3., 1., 0., 1., 0., 4., 3., 4., 0., 2., 1., 1., 1., 3., 0., 2., 2., 4., 3., 1., 3., 2., 2., 2., 1., 3., 1., 2., 0., 1., 2., 4., 4., 3., 1., 1., 4., 0., 3., 2., 2., 4., 2., 3., 1., 4., 4., 2., 1., 2., 3., 1., 3., 2., 2., 1., 1., 2., 1., 0., 2., 3., 1., 6., 3., 6., 1., 3., 1., 1., 1., 1., 4., 0., 1., 2., 2., 2., 4., 1., 5., 1., 4., 2., 4., 3., 4., 3., 1., 1., 4., 4., 3., 1., 0., 1., 0., 2., 4., 3., 1., 0., 0., 0., 1., 1., 0.}; std::vector exp_rate = {0.03333622, 0.0306063 , 0.04309129, 0.01726605, 0.05848879, 0.04340514, 0.039172 , 0.05559085, 0.04965925, 0.0497478 , 0.04369979, 0.03145105, 0.03705106, 0.03814378, 0.04841874, 0.0322569 , 0.03398314, 0.04894494, 0.03292415, 0.0375475 , 0.0455243 , 0.03845066, 0.04468348, 0.03466425, 0.05600959, 0.03726527, 0.06423618, 0.0865993 , 0.03667581, 0.07737593, 0.0415975 , 0.05794754, 0.03126112, 0.06895451, 0.01081375, 0.02659674, 0.0477702 , 0.04162693, 0.02447072, 0.00582356, 0.02449889, 0.06880492, 0.01815125, 0.05942088, 0.0427411 , 0.03762974, 0.0389627 , 0.04847999, 0.02887519, 0.03210937, 0.05698302, 0.07007875, 0.04076768, 0.03027806, 0.0313923 , 0.03152634, 0.01855677, 0.02856149, 0.03472159, 0.00446751, 0.04558219, 0.03850082, 0.01223826, 0.03443143, 0.03178761, 0.06809013, 0.06453538, 0.05871544, 0.02376645, 0.02716408, 0.04674467, 0.03262925, 0.02606126, 0.04206898, 0.05217626, 0.03792 , 0.02735688, 0.02288691, 0.02120666, 0.04580953, 0.01999294, 0.06764128, 0.01909269, 0.05315785, 0.06608396, 0.0267314 , 0.08355416, 0.0454885 , 0.02439451, 0.01710991, 0.03155962, 0.02914549, 0.0246386 , 0.0245522 , 0.02433587, 0.02585896, 0.04783398, 0.03035415, 0.06427175, 0.01224084, 0.01977881, 0.03481975, 0.02991084, 0.0337163 , 0.03774938, 0.01830768, 0.05578025, 0.05068826, 0.0348872 , 0.03381498, 0.01481279, 0.04952758, 0.032675 , 0.05256039, 0.04350085, 0.02896997, 0.02406046, 0.05554632, 0.02256609, 0.00319576, 0.03664544, 0.0170515 , 0.02155972, 0.04722373, 0.07208294, 0.03945534, 0.06155634, 0.04798413, 0.05267582, 0.02085835, 0.04255174, 0.02286321, 0.04759915, 0.01402018, 0.02632928, 0.04703806, 0.05464922, 0.07768663, 0.03687194, 0.01304395, 0.04255925, 0.0407749 , 0.04199519, 0.0256526 , 0.03201405, 0.02632585, 0.00459957, 0.01746946, 0.0774727 , 0.01817982}; std::vectorerror_rate = {0.01464807, 0.01701623, 0.01674587, 0.00950158, 0.02101601, 0.02054277, 0.01860341, 0.02080362, 0.02046153, 0.01944152, 0.01848339, 0.01645704, 0.01566297, 0.01860163, 0.02079277, 0.01380471, 0.0146883 , 0.02043707, 0.01597809, 0.01612922, 0.02063284, 0.01859966, 0.02055015, 0.01542962, 0.02127489, 0.01657009, 0.02315265, 0.02813078, 0.01850004, 0.02468196, 0.0183767 , 0.02147546, 0.01513164, 0.02282994, 0.00370025, 0.01327215, 0.02070803, 0.0194092 , 0.01313114, 0.00235739, 0.01321946, 0.02338608, 0.01315944, 0.02242559, 0.01842067, 0.01633392, 0.01704507, 0.01971375, 0.01438112, 0.01595163, 0.02095208, 0.02454507, 0.01828339, 0.01583231, 0.01586552, 0.01583689, 0.00980807, 0.01371959, 0.01840059, 0.00199599, 0.02063532, 0.01704064, 0.00437896, 0.01598774, 0.01455256, 0.02330032, 0.024449 , 0.02276699, 0.01326344, 0.01613333, 0.01879613, 0.01595487, 0.01327323, 0.02082585, 0.02148278, 0.01694008, 0.01264983, 0.01138786, 0.0129304 , 0.01954649, 0.01006418, 0.02337224, 0.01011987, 0.02068187, 0.02131174, 0.01346245, 0.02760753, 0.01875459, 0.01326657, 0.00967173, 0.01701921, 0.01360327, 0.01321431, 0.01312304, 0.01313148, 0.01173153, 0.01804841, 0.01376714, 0.0246953 , 0.00915951, 0.01103873, 0.01840394, 0.01451468, 0.01461364, 0.01852768, 0.01342717, 0.02267849, 0.02268661, 0.01478637, 0.0183984 , 0.00942078, 0.02046417, 0.01875806, 0.0206504 , 0.01852595, 0.01619451, 0.01326541, 0.02339101, 0.01125717, 0.00049457, 0.01689324, 0.00703644, 0.01020404, 0.02068478, 0.02627504, 0.01714794, 0.02156343, 0.01874872, 0.02061318, 0.0129285 , 0.01735947, 0.01307044, 0.01649357, 0.00935911, 0.01341358, 0.01929281, 0.02256545, 0.02472916, 0.01854394, 0.00921171, 0.01841888, 0.01873798, 0.01851788, 0.01325113, 0.01594256, 0.01346239, 0.00200874, 0.00972428, 0.02588486, 0.00996373}; std::vectoreffi = {0.99134749, 0.99308105, 0.99328767, 0.99181429, 0.98890057, 0.98685658, 0.98528176, 0.9843631 , 0.98407819, 0.98390969, 0.98383689, 0.98382637, 0.98401469, 0.98468303, 0.98532172, 0.98596428, 0.9866601 , 0.98685431, 0.98682859, 0.98661325, 0.98639776, 0.98618215, 0.98596632, 0.98529853, 0.98417458, 0.98172766, 0.97866114, 0.97502356, 0.97565518, 0.97715452, 0.97940213, 0.98124665, 0.98280945, 0.98406497, 0.98470674, 0.98519091, 0.98536514, 0.98553949, 0.98574277, 0.98606417, 0.98647657, 0.98693541, 0.98739456, 0.98794143, 0.98856713, 0.98949096, 0.99041518, 0.99133977, 0.99226511, 0.9931908 , 0.99411691, 0.99504372, 0.99535343, 0.99470396, 0.99389909, 0.99310071, 0.99230252, 0.99150458, 0.99070678, 0.98990919, 0.98911183, 0.98831462, 0.98751764, 0.98672087, 0.98592424, 0.98512786, 0.98433168, 0.98353563, 0.98273986, 0.98194426, 0.9811488 , 0.98035364, 0.97955862, 0.97876376, 0.97796919, 0.97717475, 0.9763805 , 0.97558651, 0.9750474 , 0.97504689, 0.97551234, 0.97610357, 0.97669491, 0.97728637, 0.97787791, 0.97846958, 0.97906135, 0.9796532 , 0.98024519, 0.98083727, 0.98142943, 0.98202174, 0.98261413, 0.9832066 , 0.98379923, 0.98439193, 0.98498472, 0.98557766, 0.98617067, 0.98676378, 0.98735703, 0.98795025, 0.98854336, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571, 0.98868571}; std::vector err_effi = {0.00220069, 0.00209908, 0.00212747, 0.00229716, 0.00258331, 0.00279055, 0.00295396, 0.00305513, 0.00307888, 0.00308899, 0.00308893, 0.00308307, 0.0030586 , 0.00298919, 0.0029183 , 0.00284384, 0.00275777, 0.00271815, 0.00269187, 0.00268292, 0.00267401, 0.00266514, 0.00265632, 0.00270261, 0.00280069, 0.00304298, 0.00337649, 0.00380208, 0.00376127, 0.00362842, 0.00341537, 0.00323357, 0.00307437, 0.00293976, 0.00285971, 0.00279897, 0.00277898, 0.00275897, 0.00273675, 0.00270555, 0.00266753, 0.00262603, 0.00258445, 0.00253313, 0.00247296, 0.00237824, 0.00228342, 0.00218852, 0.00209344, 0.00199828, 0.00190302, 0.00180759, 0.00177468, 0.00183871, 0.00192671, 0.00201494, 0.00210314, 0.00219131, 0.00227946, 0.00236757, 0.00245565, 0.00254372, 0.00263175, 0.00271975, 0.00280772, 0.00289567, 0.00298358, 0.00307148, 0.00315933, 0.00324716, 0.00333497, 0.00342274, 0.00351049, 0.00359822, 0.0036859 , 0.00377356, 0.0038612 , 0.0039488 , 0.00400944, 0.00401303, 0.00396704, 0.00390765, 0.00384823, 0.00378881, 0.00372937, 0.00366992, 0.00361046, 0.00355099, 0.0034915 , 0.00343199, 0.00337248, 0.00331295, 0.00325341, 0.00319386, 0.00313429, 0.00307472, 0.00301513, 0.00295552, 0.0028959 , 0.00283627, 0.00277663, 0.00271698, 0.00265735, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304, 0.00264304}; double duration = 23.833391203703705; using namespace ROOT::VecOps; RVec effi_vec = effi; double mean_eff = Mean(effi_vec); double std_eff = StdDev(effi_vec); unsigned int nparams = 2; auto normlog = [&](const double x, double mean, double sigma){ // if we have a delta function, return fixed value if (sigma == 0.) return 0.; // if sigma is negative use absolute value if (sigma < 0.) sigma *= -1.; double arg = (x - mean) / sigma; double result = -.5 * arg * arg; // subtract the log of the denominator of the normalization constant // and return return result - log(sqrt(2. * M_PI) * sigma); }; auto loglikelihood=[&](const double *params){ double loglike=1; for(size_t i = 0;i init(nparams); init[1]=2.5; init[0]=mean_eff; ROOT::Math::Functor fcn (loglikelihood, nparams); ROOT::Fit::Fitter fitter; bool SetStatus = fitter.SetFCN(fcn); fitter.Config().SetParamsSettings(nparams,init.data()); if(!SetStatus){ std::cout<<"Failed to set the function"<