多项式求导程序.m

本人利用MATLAB处理了并总结了工程上经常用到的“信号处理”的源代码

%求取导数公式的系数
m=input('m=');					%键盘输入m
k=input('k=');					%键盘输入k，k-1次多项式
p=input('p=');                  %键盘输入实验数据点数p
n=2*m+1;
y=[0.142,0.176,0.215,0.260,0.309,0.363,0.419,0.479,0.539,0.598,0.654,0.706,0.752,0.789,0.817,0.834,0.840,0.834,0.817,0.789,0.752,0.706,0.654,0.598,0.539,0.479,0.419,0.363,0.309,0.260,0.215,0.176,0.142,0.113,0.089,0.068,0.052,0.039,0.029,0.021];
x=zeros(n,k);
for i=-m:m							%构造X矩阵行循环
    for j=0:k-1						%构造X矩阵列循环
	    x(i+m+1,j+1)=i^j;		
    end
end
d=inv(x'*x)*x';                     %导数公式系数
yc=zeros(k - 1,p - 2 * m);          %存放导数结果的矩阵
ax=1:1:p;                           %原始数据点的序号
axc=m+1:1:p-m;                      %导数结果的序号
for i = 2:k
    for j = m + 1:p - m
        for q = 1: n
            yc(i-1,j-m)=yc(i-1,j-m)+y(j-m+q-1)*d(i,q);      %导数计算
        end
    end
end
subplot(1,2,1)                      %设置画图区域为水平排列,两个区域
plot(ax,y,'.-',axc,yc,'.-r')        %画出原始数据与导数结果的图形
subplot(1,2,2)                      %设置图形区域
plot(axc,yc,'.-r')                  %画出导数结果图