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