用matlab程序绘制空间曲线的切平面，法平面，密切平面。以下是部分程序，能不能优化？

```syms t
x1 = cos(t);
y1 = sin(t);                         
z1 = t; 
t=0;
x2 =cos(0);               
y2 =sin(0);                 
z2 =0;            
t =linspace(0,2*pi,100);                              
x3= eval(x1);
y3 = eval(y1);
z3= eval(z1);
figure                                              
hold on
plot3(x3,y3,z3)
xlabel('x')
ylabel('y')
zlabel('z')

% 切线
fx = diff(x1,1,'t');                           
fy = diff(y1,1,'t');
fz = diff(z1,1,'t');
s1= subs( fx, 't',0);                               
d1= subs( fy,'t', 0);
f1= subs( fz, 't',0);
a=-4:0.1:4;                                                              
xx = a*s1+x2;                                                           
yy = a*d1+y2;                                      
zz = a*f1+z2;
hold on
view(3);
plot3(xx,yy,zz,'linewidth',2)
xlabel('x')
ylabel('y')
zlabel('z')
xlab = -1:0.1:1;                                                
[xxx ,yyy] = meshgrid(xlab);                               
zzzz=double((-s1.*(xxx-x2)-d1.*(yyy-y2))/f1 );
zzz=zzzz+z2;
mesh(xxx,yyy,zzz)
xlabel('x')
ylabel('y')
zlabel('z')