随机过程matlab程序(材料相关)

基本操作

-5/(4.8+5.32)^2

area=pi*2.5^2

x1=1+1/2+1/3+1/4+1/5+1/6

exp(acos(0.3))

a=[1 2 3;4 5 6;7 8 9]

a=[1:3,4:6,7:9]

a1=[6: -1:1]

a=eye(4) a1=eye(2,3) b=zeros(2,10) c=ones(2,10) c1=8*ones(3,5) d=zeros(3,2,2)；

r1=rand(2, 3)

r2=5-10*rand(2, 3)

r4=2*randn(2,3)+3

arr1=[1.1 -2.2 3.3 -4.4 5.5]

arr1(3) arr1([1 4]) arr1(1:2:5)

arr2=[1 2 3; -2 -3 -4;3 4 5]

arr2(1,:)

arr2(:,1:2:3)

arr3=[1 2 3 4 5 6 7 8]

arr3(5:end) arr3(end)

绘图

x=[0:1:10];

y=x.^2-10*x+15;

plot(x,y)

x=0:pi/20:2*pi

y1=sin(x);y2=cos(x);

plot(x,y1,'b-');

hold on;

plot(x,y2,‘k--’);

legend (‘sin x’,‘cos x’);

x=0:pi/20:2*pi;

y=sin(x);

figure(1)

plot(x,y, 'r-')

grid on

以二元函数图 z = xexp(-x^2-y^2) 为例讲解基本操作，首先需要利用meshgrid 函数生成X-Y平面的网格数据，如下所示：

xa = -2:0.2:2;

ya = xa;

[x,y] = meshgrid(xa,ya);

z = x.*exp(-x.^2 - y.^2);

mesh(x,y,z);

建立M文件

function fenshu( grade )

if grade > 95.0

disp('The grade is A.');

else

if grade > 86.0

disp('The grade is B.');

else

if grade > 76.0

disp('The grade is C.');

else

if grade > 66.0

disp('The grade is D.');

else

disp('The grade is F.');

end

end

end

end

end

function y=func(x)

if abs(x)<1

y=sqrt(1-x^2);

else y=x^2-1;

end

function summ( n)

i = 1;

sum = 0;

while ( i <= n )

sum = sum+i;

i = i+1;

end

str = ['¼ÆËã½á¹ûΪ£º',num2str(sum)]; disp(str)

end

求极限

syms x

limit((1+x)^(1/x),x,0,'right')

求导数

syms x;

f=(sin(x)/x);

diff(f)

diff(log(sin(x)))

求积分

syms x;

int(x^2*log(x))

syms x;

int(abs(x-1),0,2)

常微分方程求解

dsolve('Dy+2*x*y=x*exp(-x^2)','x')

计算偏导数

x/(x^2 + y^2 + z^2)^(1/2)

diff((x^2+y^2+z^2)^(1/2),x,2)

重积分

int(int(x*y,y,2*x,x^2+1),x,0,1)

级数

syms n;

symsum(1/2^n,1,inf)

Taylor展开式

求y=exp(x)在x=0处的5阶Taylor展开式

taylor(exp(x),0,6)

矩阵求逆

A=[0 -6 -1; 6 2 -16; -5 20 -10]

det(A)

inv(A)

特征值、特征向量和特征多项式

A=[0 -6 -1; 6 2 -16; -5 20 -10];

lambda=eig(A)

[v,d]=eig(A)

poly(A)

多项式的根与计算