www.gusucode.com > Matlab精彩编程100例源码程序 > Matlab精彩编程100例源码/work/shili85.m

    h0=figure('toolbar','none',...
    'position',[200 50 350 450],...
    'name','实例85');
h1=axes('parent',h0,...
    'position',[0.10 0.45 0.8 0.5],...
    'visible','off');
x=0:0.2:2*pi;
y=sin(x);
plot(x,y)
b1=uicontrol('parent',h0,...
    'units','points',...
    'tag','b1',...
    'style','pushbutton',...
    'string','拉格朗日插值',...
    'backgroundcolor',[0.75 0.75 0.75],...
    'position',[20 60 70 20],...
    'callback',[...
        'cla,',...
        'strn=get(e1,''string'');,',...
        'n=str2num(strn);,',...
        'i=1;,',...
        'x=0:0.2:2*pi;,',...
        'for t=0:0.2:2*pi,',...
        'y(i)=sin(t);,',...
        'L(i)=lag(t,n);,',...
        'i=i+1;,',...
        'end,',...
        'plot(x,y,''b*'',x,L,''r-''),',...
        'legend(''sin(x)'',''插值函数'');,',...
        'axis([0 7 -1.5 1.5])']);
b2=uicontrol('parent',h0,...
    'units','points',...
    'tag','b2',...
    'style','pushbutton',...
    'string','误差比较',...
    'backgroundcolor',[0.75 0.75 0.75],...
    'position',[170 60 70 20],...
    'callback',[...
        'strn=get(e1,''string'');,',...
        'n=str2num(strn);,',...
        'strm=get(e2,''string'');,',...
        'm=str2num(strm);,',...
        'dd=abs(sin(m)-lag(m,n));,',...
        'msgbox([''误差为：'',num2str(dd)],''计算结果'')']);
e1=uicontrol('parent',h0,...
    'units','points',...
    'tag','e1',...
    'style','edit',...
    'fontsize',12,...
    'string','5',...
    'horizontalalignment','right',...
    'backgroundcolor',[1 1 1],...
    'position',[50 100 40 20]);
e2=uicontrol('parent',h0,...
    'units','points',...
    'tag','e2',...
    'style','edit',...
    'fontsize',12,...
    'string','1.20',...
    'horizontalalignment','right',...
    'backgroundcolor',[1 1 1],...
    'position',[200 100 40 20]);
t1=uicontrol('parent',h0,...
    'units','points',...
    'tag','t1',...
    'style','text',...
    'string','阶数：',...
    'fontsize',12,...
    'backgroundcolor',[0.75 0.75 0.75],...
    'position',[20 100 30 20]);
t2=uicontrol('parent',h0,...
    'units','points',...
    'tag','t2',...
    'style','text',...
    'string','误差点：',...
    'fontsize',12,...
    'backgroundcolor',[0.75 0.75 0.75],...
    'position',[160 100 40 20]);
b3=uicontrol('parent',h0,...
    'units','points',...
    'tag','b3',...
    'style','pushbutton',...
    'string','关闭',...
    'backgroundcolor',[0.75 0.75 0.75],...
    'position',[100 20 60 20],...
    'callback','close');