TAILIEUCHUNG - Integration of Ordinary Differential Equations part 4

(y,dydx,nvar,&x,h,eps,yscal,&hdid,&hnext,derivs); if (hdid == h) ++(*nok); else ++(*nbad); if ((x-x2)*(x2-x1) = ) { Are we done? for (i=1;i | 722 Chapter 16. Integration of Ordinary Differential Equations rkqs y dydx nvar x h eps yscal hdid hnext derivs if hdid h nok else nbad if x-x2 x2-x1 Are we done for i 1 i nvar i ystart i y i if kmax xp kount x Save final step. for i 1 i nvar i yp i kount y i free_vector dydx 1 nvar free_vector y 1 nvar free_vector yscal 1 nvar return Normal exit. if fabs hnext hmin nrerror Step size too small in odeint h hnext nrerror Too many steps in routine odeint CITED REFERENCES AND FURTHER READING Gear . 1971 Numerical Initial Value Problems in Ordinary Differential Equations Englewood Cliffs NJ Prentice-Hall . 1 Cash . and Karp . 1990 ACM Transactions onMathematical Software vol. 16 pp. 201222. 2 Shampine . and Watts . 1977 in Mathematical Software III . Rice ed. New York Academic Press pp. 257-275 1979 Applied Mathematics and Computation vol. 5 pp. 93-121. Forsythe . Malcolm . and Moler . 1977 Computer Methods for Mathematical Computations Englewood Cliffs NJ Prentice-Hall . Modified Midpoint Method This section discusses the modified midpoint method which advances a vector of dependent variables y x from a point x to a point x H by a sequence of n substeps each of size h h H n In principle one could use the modified midpoint method in its own right as an ODE integrator. In practice the method finds its most important application as a part of the more powerful Bulirsch-Stoer technique treated in . You can therefore consider this section as a preamble to . The number of right-hand side evaluations required by the modified midpoint method is n 1. The formulas for the method are zo y x Z1 zo hf x zo Sample page from NUMERICAL RECIPES IN C THE ART OF SCIENTIFIC COMPUTING ISBN 0-521-43108-5 zm i zm-i 2hf x mh zm for m 1 2 . n 1 y x H yn 2 z zn-i hf x H zn Modified Midpoint Method 723 Here the z s are intermediate approximations which march along in steps of h while yn is the final approximation to y x H . The method

TÀI LIỆU MỚI ĐĂNG
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.