matlab 编写公式

1. matlab 编写公式

程序如下：（复制就能运行）
t=-5:0.001:5;w=(1-t.^2/10).*exp(-t.^2/2).*cos(0.5.*t);%所要编写的公式plot(t,w)%该公式对应的函数图grid on

2. 用matlab写公式

v=[...]  %n行×m列
Np=[...]  %n行×m列
XN=sqrt(sum((v-Np).^2./Np))

3. matlab写公式

给个例子，注意并不是所有的五元二次方程组都有解。
syms x y z s t
f1=x+y-z+s+t;
f2=x^2-y^2+2*z;
f3=x*y+s*t;
f4=z-s*t;
f5=x^2+y^2-2*t;
[x,y,z,s,t]=solve(f1,f2,f3,f4,f5);
解得：
x =
 
            0
  1/2*2^(1/2)
  1/2*2^(1/2)
 -1/2*2^(1/2)
 -1/2*2^(1/2)
 
 
 
y =
 
                      0
 1+(-2-2*2^(1/2))^(1/2)
 1-(-2-2*2^(1/2))^(1/2)
 1+(-2+2*2^(1/2))^(1/2)
 1-(-2+2*2^(1/2))^(1/2)
 
 
 
z =
 
                                                                                                                 0
   -(2^(1/2)-1)*(1+(-2-2*2^(1/2))^(1/2))/(1/2*2^(1/2)*(1+(-2-2*2^(1/2))^(1/2))-1/2*2^(1/2)-1-(-2-2*2^(1/2))^(1/2))
   -(2^(1/2)-1)*(1-(-2-2*2^(1/2))^(1/2))/(1/2*2^(1/2)*(1-(-2-2*2^(1/2))^(1/2))-1/2*2^(1/2)-1+(-2-2*2^(1/2))^(1/2))
 -(-1-2^(1/2))*(1+(-2+2*2^(1/2))^(1/2))/(-1/2*2^(1/2)*(1+(-2+2*2^(1/2))^(1/2))+1/2*2^(1/2)-1-(-2+2*2^(1/2))^(1/2))
 -(-1-2^(1/2))*(1-(-2+2*2^(1/2))^(1/2))/(-1/2*2^(1/2)*(1-(-2+2*2^(1/2))^(1/2))+1/2*2^(1/2)-1+(-2+2*2^(1/2))^(1/2))
 
 
 
s =
 
                                                                                                     0
  1/(1/2*2^(1/2)*(1+(-2-2*2^(1/2))^(1/2))-1/2*2^(1/2)-1-(-2-2*2^(1/2))^(1/2))*(1+(-2-2*2^(1/2))^(1/2))
  1/(1/2*2^(1/2)*(1-(-2-2*2^(1/2))^(1/2))-1/2*2^(1/2)-1+(-2-2*2^(1/2))^(1/2))*(1-(-2-2*2^(1/2))^(1/2))
 1/(-1/2*2^(1/2)*(1+(-2+2*2^(1/2))^(1/2))+1/2*2^(1/2)-1-(-2+2*2^(1/2))^(1/2))*(1+(-2+2*2^(1/2))^(1/2))
 1/(-1/2*2^(1/2)*(1-(-2+2*2^(1/2))^(1/2))+1/2*2^(1/2)-1+(-2+2*2^(1/2))^(1/2))*(1-(-2+2*2^(1/2))^(1/2))
 
 
 
t =
 
                                     0
  1/2*2^(1/2)*(1+(-2-2*2^(1/2))^(1/2))
  1/2*2^(1/2)*(1-(-2-2*2^(1/2))^(1/2))
 -1/2*2^(1/2)*(1+(-2+2*2^(1/2))^(1/2))
 -1/2*2^(1/2)*(1-(-2+2*2^(1/2))^(1/2))

4. 利用matlab表示公式

可这样：
A=magic(3);
b=3*ones(3,3);
c=cross(A,b)
结果：
c =
    -3   -12    15
   -12    24   -12
    15   -12    -3

5. matlab编程编辑公式

如果总用户等数据已知，各个用户的，等已知，即可以将SFL1,rFL1,SFL2,rFL2,等写成向量形式，例如可以写成如下形式：
Sr1=SFL1.*rFL1;
Sr2=SFL2.*rFL2;
PFL=sum(Sr1(1:NFC))/sum(Sr2(1:NSC));

6. 使用matlab编写函数，

%%
当x6,f(x)=0.5;
%
并调用此函数，绘制在x=[0,2]范围的f(x)*f(x+2)曲线。
%
根据题意，编写如下函数并保存为funcfx.m
function
fx
=
funcfx(x)
n=length(x);
fx=[];
for
i=1:n
   
if
x(i)
<=
2
       
fx(i)
=
0.5
.*
x(i);
   
elseif
(x(i)
>
2)
&
(x(i)
<=
6)
       
fx(i)
=
1.5
-
0.25
.*
x(i);
   
elseif
x(i)>6
       
fx(i)
=
0.5;
   
end
end 
 
保存函数后调用，代码如下：
x=-6:20;
fx=funcfx(x);
plot(x,fx,'r*')

7. matlab 计算 该怎么写

用matlab计算此极限问题，需要使用三个命令，即limit（）极限命令、sqrt（）开方命令、symsum（）求和命令。
计算代码
syms k n
limit(sqrt(symsum(k,1,n))-sqrt(symsum(k,1,n-1)),n,inf)
vpa(ans)
计算结果

8. 用matlab编写，求解

x = 0:0.1:12
plot(x,besselj(1,pi*x),x,0)  %画图形，观察根（零点）的位置
r(1) = fsolve(@(x)besselj(1,pi*x),1.2);    %求根
r(2) = fsolve(@(x)besselj(1,pi*x),2.2);
r(3) = fsolve(@(x)besselj(1,pi*x),3.2);
r(4) = fsolve(@(x)besselj(1,pi*x),4.2);
r(5) = fsolve(@(x)besselj(1,pi*x),5.2);
r(6) = fsolve(@(x)besselj(1,pi*x),6.2);
r(7) = fsolve(@(x)besselj(1,pi*x),7.2);
r(8) = fsolve(@(x)besselj(1,pi*x),8.2);
r(9) = fsolve(@(x)besselj(1,pi*x),9.2);
r(10) = fsolve(@(x)besselj(1,pi*x),10.2);

结果为：
r =
1.2197    2.2331    3.2383    4.2411    5.2428    6.2439    7.2448    8.2454    9.2459   10.2463