www.gusucode.com > symbolic 源码程序 matlab案例代码 > symbolic/SparseMatricesOdeFunctionExample.m
%% Sparse Matrices %% 1 syms x1(t) x2(t) a = -0.6; b = -0.1; r = @(t) cos(t)/(1 + t^2); eqs = [diff(x1(t),t) == a*x1(t) + b*x2(t)^2,... x1(t)^2 + x2(t)^2 == r(t)^2]; vars = [x1(t), x2(t)]; [M, F] = massMatrixForm(eqs, vars); M = odeFunction(M, vars, 'Sparse', true); F = odeFunction(F, vars); t0 = 0; y0 = [-r(t0)*sin(0.1); r(t0)*cos(0.1)]; yp0 = [a*y0(1) + b*y0(2)^2; 1.234]; opt = odeset('mass', M, 'InitialSlope', yp0); %% 2 ode15s(F, [t0, 1], y0, opt)