大家帮我看一下这个用Mathematica编写的求振动系统瞬态响应的程序，不知道什么问题，没办法运行呢

m = ( { {2, 0}, {0, 1} } );c = ( { {0, 0}, {0, 0} } );k = ( { {6, -2}, {-2, 4} } );f = {0, 10};x0 = {0, 0};v0 = {0, 0};\[CapitalDelta]t = 0.28;n = 12;\[Gamma] = 1/2.;\[Beta] = 1/4.;a = Newmark[m, c, k, f, x0, v0, \[CapitalDelta]t, n, \[Gamma], \[Beta]];Table[a[ ][[1(*1是位移,2是速度,3是加速度*)]][[1(*第1个节点的运动量*)]], {i, 1, n + 1}]ListPlot[%, PlotJoined -> True]m = ( { {1, 0}, {0, 1} } );c = ( { {2, -1}, {-1, 1} } );k = ( { {6, -5}, {-5, 5} } );f = {0, Sin[t]};x0 = {-(7/15.), -(3/5.)};v0 = {-(3/5.), -(8/15.)};\[CapitalDelta]t = \[Pi]/10.;n = 20;\[Gamma] = 1/2.;\[Beta] = 1/4.;a = Newmark[m, c, k, f, x0, v0, \[CapitalDelta]t, n, \[Gamma], \[Beta]];Table[a[][[1(*1是位移,2是速度,3是加速度*)]][[2(*第2个节点的运动量*)]], {i, 1, n + 1}]ListPlot[%, PlotJoined -> True]
大家帮我看一下这个用Mathematica编写的求振动系统瞬态响应的程序，不知道什么问题，没办法运行呢