MATLAB程序调试问题： while x(i)<=2 | Error: Illegal use of reserved keyword "while".

Question

>> N=10000;
c=3e8;
e=1.6e-19;
me=9.1e-31;
re=e^2/(me*c^2);
theta=0;
t=0;
yo=normrnd(0,1,1,10000);
hv=normrnd(10*e,e,1,10000);
xe=1+rand(1,10000);
ye=rand(1,10000);
vxe=normrnd(2,0.5,1,10000);
vye=normrnd(2,0.5,1,10000);
y=yo+c*t*sin(theta) ;
px=hv/c*cos(theta);
py=hv/c*sin(theta);
x=c*t*cos(theta);
pxe=me*vxe;
pye=me*vye;
sym t;
for i=1:10000
{
while x(i)<=2
{
for j=1:10000
{
if (sqrt((x(i)-xe(j))^2+(y(i)-ye(j))^2)<=re & (px(i)*(x(i)-xe(j))+py(i)*(y(i)-ye(j))>0))
{
syms hvp(10000),thetap,pxep(10000),pyep(10000);
[hvp(i),thetap,pxep(j),pyep(j)]=solve('hv(i)+(pxe(j)^2+pye(j)^2)/(2*me)= hvp(i)+(pxep(j)^2+pyep(j)^2)/(2*me)','hv(i)/c*cos(theta)+pxe(j)=hvp(i)/c*cos(thetap)+pxep(j)','hv(i)/c* sin(theta)+pye(j)=hvp(i)/c*sin(thetap)+pyep(j)','(hvp(i)/c*[cos(thetap),sin(thetap)]-hv(i)/c*[cos(theta),sin(theta)])./norm(hvp(i)/c*[cos(thetap),sin(thetap)]-hv(i)/c*[cos(theta),sin(theta)])=[x(i)-xe(j),y(i)-ye(j)]/norm([x-xe(j),y(i)-ye(j)])','hvp(i)','thetap','pxep(j)','pyep(j)')
hv(i)=hvp(i);
theta=thetap;
pxe(j)=pxep(j);
pye(j)=pyep(j);
}
end
}
end
t=t+1e-12;
}
end
t=0;
}
end
while x(i)<=2
|
Error: Illegal use of reserved keyword "while".

Answer 1

N=10000;
c=3e8;
e=1.6e-19;
me=9.1e-31;
re=e^2/(me*c^2);
theta=0;
t=0;
yo=normrnd(0,1,1,10000);
hv=normrnd(10*e,e,1,10000);
xe=1+rand(1,10000);
ye=rand(1,10000);
vxe=normrnd(2,0.5,1,10000);
vye=normrnd(2,0.5,1,10000);
y=yo+c*t*sin(theta) ;
px=hv/c*cos(theta);
py=hv/c*sin(theta);
x=c*t*cos(theta);
pxe=me*vxe;
pye=me*vye;
sym t;
for i=1:10000

while x(i)<=2

for j=1:10000

if (sqrt((x(i)-xe(j))^2+(y(i)-ye(j))^2)<=re & (px(i)*(x(i)-xe(j))+py(i)*(y(i)-ye(j))>0))

syms hvp(10000),thetap,pxep(10000),pyep(10000);
[hvp(i),thetap,pxep(j),pyep(j)]=solve('hv(i)+(pxe(j)^2+pye(j)^2)/(2*me)= hvp(i)+(pxep(j)^2+pyep(j)^2)/(2*me)','hv(i)/c*cos(theta)+pxe(j)=hvp(i)/c*cos(thetap)+pxep(j)','hv(i)/c* sin(theta)+pye(j)=hvp(i)/c*sin(thetap)+pyep(j)','(hvp(i)/c*[cos(thetap),sin(thetap)]-hv(i)/c*[cos(theta),sin(theta)])./norm(hvp(i)/c*[cos(thetap),sin(thetap)]-hv(i)/c*[cos(theta),sin(theta)])=[x(i)-xe(j),y(i)-ye(j)]/norm([x-xe(j),y(i)-ye(j)])','hvp(i)','thetap','pxep(j)','pyep(j)')
hv(i)=hvp(i);
theta=thetap;
pxe(j)=pxep(j);
pye(j)=pyep(j);

end

end
t=t+1e-12;

end
t=0;

end
% while x(i)<=2

你需要把那些括号全都去掉才行

Answer 2

matlab编程的时候循环体、分支结构等都不是用花括号区分的，而是用
while....end
for...end
if...end
等进行区分，和其他语言不大一样，你要小心。