4.m

matlab的基础应用,主要是基础部芬的学习笔记,大家看看有没有用!

 sym
 syms
 y=2*sin(x)*cos(x)
 y=sym('2*sin(x)*cos(x)')
 syms A t tao w;yf=int(A*exp(-i*w*t),t,-tao/2,tao/2);yf=simple(yf)
 int
 diff(f,t,2)
 diff(diff(f,x),t)
 syms x y z
 F2=int(int(int(x^2+y^2+z^2,z,sqrt(x*y),x^2*y),y,sqrt(x),x^2),x,1,2)
 symsum(f,v,a,b)
 syms k t;f1=[t,k^3];
 s1=simple(symsum(f1))
A=sym([1,1/2,1/2,-1;1,1,-1,1;1,-1/4,-1,1;-8,-1,1,1]);
b=sym([0;10;0;1]);X1=A\b
A2=A(1:3,:);X2=A2\b(1:3,1)
syms k;
XX2=X2+k*null(A2)
A2*XX2
syms d n p q;eq1=d+n/2+p/2-q;eq2=n+d+q-p-10;eq3=q+d-n/4-p;
S=solve(eq1,eq2,eq3,d,n,p,q);S.d,S.n,S.p,S.q
S=dsolve('Dx=y,Dy=-x');
disp([S.x,S.y])
y=dsolve('x*D2y-3*Dy=x^2','y(1)=0,y(5)=0','x')
S=dsolve('Df=3*f+4*g,Dg=-4*f+3*g','f(0)=0,f(3)=1')
S.f,S.g