butools.ph.MomentsFromME ======================== .. currentmodule:: butools.ph .. np:function:: MomentsFromME .. list-table:: :widths: 25 150 * - Matlab: - :code:`moms = MomentsFromME(alpha, A, K, prec)` * - Mathematica: - :code:`moms = MomentsFromME[alpha, A, K, prec]` * - Python/Numpy: - :code:`moms = MomentsFromME(alpha, A, K, prec)` Returns the first K moments of a matrix-exponential distribution. Parameters ---------- alpha : vector, shape (1,M) The initial vector of the matrix-exponential distribution. A : matrix, shape (M,M) The matrix parameter of the matrix-exponential distribution. K : int, optional Number of moments to compute. If K=0, 2*M-1 moments are computed. The default value is K=0. prec : double, optional Numerical precision for checking the input. The default value is 1e-14. Returns ------- moms : row vector of doubles The vector of moments. Examples ======== For Matlab: >>> a = [0.2,0.3,0.5]; >>> A = [-1, 0, 0; 0, -3, 2; 0, -2, -3]; >>> moms = MomentsFromME(a, A); >>> disp(moms); 0.35385 0.41893 1.1552 4.6998 23.838 >>> moms = MomentsFromME(a, A, 9); >>> disp(moms); Columns 1 through 6 0.35385 0.41893 1.1552 4.6998 23.838 143.78 Columns 7 through 9 1007.8 8064.3 72578 For Mathematica: >>> a = {0.2,0.3,0.5}; >>> A = {{-1, 0, 0},{0, -3, 2},{0, -2, -3}}; >>> moms = MomentsFromME[a, A]; >>> Print[moms]; {0.35384615384615387, 0.41893491124260357, 1.1552116522530724, 4.699835439935577, 23.837756165615836} >>> moms = MomentsFromME[a, A, 9]; >>> Print[moms]; {0.35384615384615387, 0.41893491124260357, 1.1552116522530724, 4.699835439935577, 23.837756165615836, 143.78185836646944, 1007.8194071104502, 8064.272882521486, 72578.13371878522} For Python/Numpy: >>> a = ml.matrix([[0.2,0.3,0.5]]) >>> A = ml.matrix([[-1, 0, 0],[0, -3, 2],[0, -2, -3]]) >>> moms = MomentsFromME(a, A) >>> print(moms) [0.35384615384615381, 0.41893491124260357, 1.1552116522530724, 4.6998354399355771, 23.837756165615836] >>> moms = MomentsFromME(a, A, 9) >>> print(moms) [0.35384615384615381, 0.41893491124260357, 1.1552116522530724, 4.6998354399355771, 23.837756165615836, 143.78185836646944, 1007.8194071104502, 8064.2728825214863, 72578.133718785219]