Question

我正试图在特定的潜力中生成银河轨道的情节。我的代码由

提供

 function Eulersystem_MNmodel()
 parsec  = 3.08*10^18;
 r_1     = 8.5*1000.0*parsec; % This converts our value of r into cm.
 z_1     = 1.0; 
 theta_1 = 0.0; %Initial Value for Theta.

 U_1     = 100.0*10^5;     %Initial value for U in cm/sec
 V       = 156.972*10^5;   %Proposed value of the radial velocity in cm/sec
 W_1     = 150*10^5.0;

 grav    = 6.6720*10^-8;   %Universal gravitational constant
 amsun   = 1.989*10^33;    %Proposed Angular momentum of the sun
 amg   = 1.5d11*amsun; 
 gm      = grav*amg;       %Note this is constant

 nsteps  = 50000;          %The number of steps
 deltat  = 5.0*10^11;      %Measured in seconds

 angmom  = r_1*V;          %The angular momentum
 angmom2 = angmom^2.0;     %The square of the angular momentum
 E       = -gm/r_1 + U_1*U_1/2 + angmom2/(2.0*r_1*r_1); %Total Energy of the system

 time    = 0.0;

for i=1:nsteps
r_1      = r_1 + deltat*U_1;
U_1      = U_1 + deltat*((-gm*r_1)/((r_1^2.0 + (1+sqrt(z_1^2.0+1))^2.0)^1.50))
z_1      = z_1 + deltat*W_1;
W_1      = W_1 + deltat*(gm*z_1*(1+sqrt(z_1^2.0+1))/(sqrt(z_1^2.0+1))*(r_1^2.0+(1+sqrt(z_1^2.0+1))^2.0)^1.5);


E        = -gm/r_1+U_1/2.0+angmom2/(2.0*r_1*r_1); 
ecc      = (1.0 + (2.0*E*angmom2)/(gm^2.0))^0.5;
time1(i) = time;
time     = time+deltat;
r(i)     = r_1;
z(i)     = z_1;
end

figure()
plot(r,z)

我不断获得直线，而不是更有趣的曲线，这让我调查了U_1函数的输出。经过这次调查，我意识到它一直在输出NaN“非数字”。我不知道为什么我会得到这个。我尝试用（）^ 0.5替换sqrt（），这仍然产生NaN。

Answer 1

您的操作数量相当大。最大的浮点数类似于1.7e + 308。 Lager数字将评估为Inf。同样，小于1.7e-308的正数会评估为零并在分裂期间导致NaN？

MATLAB - 获取NaN错误

1 个答案: