X~2分布、t分布和f分布的性质及近似计算.doc

以下为三个分布的动画演示程序，直接运行：function dandn(action) % X2分布、t分布和f分布的性质及近似计算% 制作人： 幸玮 石岩 顾秋容% All Rights Reserved% 2008.12%无输入参数时进行初始程序,否则调界面参数if nargin1, action=initialize;else %看是哪种分布 data=get(gco,UserData); pdflabel=data(4); %图形显示参数，调试时用 switch pdflabel case 1 xstart=0; %x轴起始点 width=120; %x轴范围 xdis=30; %x轴刻度间距 lenth=0.24; %y轴范围 ydis=0.03; %y轴刻度间距 speed=0.6; %动画演进速率 case 2 width=6; xdis=3; lenth=0.42; ydis=0.05; speed=0.5; case 3 width=2; xdis=0.5; lenth=4; ydis=0.4; speed=0.8; endend %初始化模块if strcmp(action,initialize) %数据初始化 %分布函数选择 pdflabel=0; d=inputdlg(输入分布函数类型:,选择分布函数,1,x2); if strcmp(d,x2) pdflabel=1; elseif strcmp(d,t) pdflabel=2; elseif strcmp(d,f) pdflabel=3; end %不符合的输入报错 if pdflabel=0 errordlg(分布函数只能选择x2,t与f) return end %整体用户界面建立，图形显示窗口嵌入 figNumber=figure( . Name,Changing of the X2 destribution function, . NumberTitle,off, . Visible,off); axes( . Units,normalized, . Visible,off, . Position,0.06 0.065 0.70 0.9); %显示初始现实画面 switch pdflabel case 1 %初始显示参数 xstart=0; %x轴起始点 width=120; %x轴范围 xdis=30; %x轴刻度间距 lenth=0.24; %y轴范围 ydis=0.03; %y轴刻度间距 %画背景图 plot(xstart xstart+width,lenth lenth,b); hold on plot(xstart xstart+width,lenth lenth,r); plot(xstart xstart+width,lenth lenth,black); legend(X2分布,正态分布); axis(xstart xstart+width 0 lenth); grid on set(gca,XTick,xstart:xdis:xstart+width); set(gca,YTick,0:ydis:lenth); hold off %分布函数动画初始参数 m=0; n=1; case 2 width=6; xdis=3; lenth=0.42; ydis=0.05; plot(-width -width width,0 lenth lenth,b); hold on plot(-width -width width,0 lenth lenth,r-); plot(-width -width width,0 lenth lenth,black); legend(T分布,正态分布); grid on axis(-width width 0 lenth); set(gca,XTick,-width:xdis:width); set(gca,YTick,0:ydis:lenth); hold off m=0; n=2; otherwise width=2; xdis=0.5; lenth=4; ydis=0.4; plot(width,0,b); hold on plot(width,0,r); legend(f分布,正态分布); axis(0 width 0 lenth); grid on set(gca,XTick,0:xdis:width); set(gca,YTick,0:ydis:lenth); hold off %f分布输入n n=inputdlg(输入n的值:,获取n,1,5); n=str2double(n1); if n=4 errordlg(要使正态逼近式成立n必须大于4!) return end m=1; end %按钮显示位置 top=0.95; left=0.80; btnWid=0.15; btnHt=0.08; spacing=0.02; %“Start”按钮 btnNumber=1; labelStr=Start; callbackStr=dandn(start); %显示按钮 btnPos=left top-btnHt btnWid btnHt; uicontrol( . Style,pushbutton, . Units,normalized, . Position,btnPos, . String,labelStr, . Callback,callbackStr, . UserData,btnNumber m n pdflabel); %调用时的句柄参数传递 %关闭按钮 yPos=top-(btnHt+spacing); uicontrol( . Style,push, . Units,normalized, . Position,left yPos-btnHt btnWid btnHt, . String,Close, . Callback,close(gcf); set(figNumber,Visible,on); %显示初始图像 %“Start”按钮执行程序elseif strcmp(action,start) %参数初始化 data=get(gco,UserData); method=data(1); m=data(2); n=data(3); %“Stop”按钮设置，点击开始后替换“Start”按钮 btnNumber=2; labelStr=Stop; callbackStr=dandn(stop); top=0.95; left=0.80; btnWid=0.15; btnHt=0.08; btnPos=left top-btnHt btnWid btnHt; stophld=uicontrol( . Style,pushbutton, . Units,normalized, . Position,btnPos, . String,labelStr, . Callback,callbackStr, . UserData,btnNumber m n pdflabel); %画图程序 switch pdflabel case 1 while(method=1) %当未点击“Stop”则继续执行 %画x2分布密度函数 a=n/2; b=2; x=xstart:0.1:xstart+width;y=gampdf(x,a,b); plot(x,y,b,EraseMode,normal); hold on %画近似正太分布密度函数 y1=normpdf(x,n,(2*n)0.5); plot(x,y1,r-); %图形参数调节 axis(xstart xstart+width 0 lenth); set(gca,XTick,xstart:xdis:xstart+width); set(gca,YTick,0:ydis:lenth); grid on; legend(X2分布,正态分布); %显示当前n temp=num2str(floor(n); str=strcat(n=,temp); text(92,0.2,str); %显示当前最大间距 dis=num2str(max(abs(y-y1); str=strcat(dis=,dis); text(92,0.187,str); %动画指令 drawnow; hold off; n=n+speed; %看stop是否按下 data=get(gco,UserData); method=data(1); %更新传递参数 set(stophld,Userdata,btnNumber m n pdflabel); end case 2 while(method=1) %画t分布密度函数 x=-width:0.1:width;y=tpdf(x,n); plot(x,y,EraseMode,normal); hold on %画近似正太分布密度函数 y1=normpdf(x,0,(n/(n-2)0.5); plot(x,y1,r-); %图形参数调节 axis(-width width 0 lenth); set(gca,XTick,-width:xdis:width); set(gca,YTick,0:ydis:lenth); grid on; legend(T分布,正态分布); %显示当前n temp=num2str(floor(n); z=strcat(n=,temp); text(3.3,0.335,z); %显示当前最大间距 dis=num2str(max(abs(y-y1); str=strcat(dis=,dis); text(3.3,0.315,str); %动画指令 drawnow; hold off; n=n+speed; %看stop是否按下 data=get(gco,UserData); method=data(1); %更新传递参数 set(stophld,Userdata,btnNumber m n pdflabel); end otherwise while(method=1) %画f分布密度函数 x=0:0.01:width;y=fpdf(x,m,n); plot(x,y,EraseMode,normal); hold on %画近似正太分布密度函数 y1=normpdf(x,n/(n-2),(2*n2*(m+n-2)/m/(n-2)2/(n-4)0.5); plot(x,y1,r); %图形参数调节 axis(0 width 0 lenth); set(gca,XTick,0:xdis:width); set(gca,YTick,0:ydis:lenth); grid on; legend(f分布,正态分布); %显示当前m temp1=num2str(floor(m); str=strcat(m=,temp1); text(1.55,3.32,str); %显示当前n temp2=num2str(floor(n); str=strcat(n=,temp2); text(1.78,3.32,str); %显示当前最大间距 dis=num2str(max(abs(y-y1); str=strcat(dis=,dis); text(1.55,3,str); %动画指令 drawnow; hold off; m=m+speed; %看stop是否按下 data=get(gco,UserData); method=data(1); %更新传递参数 set(stophld,Userdata,btnNumber m n pdflabel); end end %“Close”按钮执行程序elseif strcmp(action,stop) data=get(gco,UserData); %读原有传递数据 top=0.95; left=0.80; btnWid=0.15; btnHt=0.08; %用“continue”按钮替代“Stop btnNumber=1; labelStr=Continue; callbackStr=dandn(continue); data(1)=btnNumber; %更新按钮标识 btnPos=left top-btnHt btnWid btnHt; uicontrol( . Style,pushbutton, . Units,normalized, . Position,btnPos, . String,labelStr, . Callback,callbackStr, . UserData,data); %“continue”按钮执行程序elseif strcmp(action,continue) %读取传递数据 data=get(gco,UserData); method=data(1); m=data(2); n=data(3); %用“Stop”按钮替代“continue” btnNumber=2; labelStr=Stop; callbackStr=dandn(stop); top=0.95; left=0.80; btnWid=0.15; btnHt=0.08; btnPos=left top-btnHt btnWid btnHt; conthld=uicontrol( . Style,pushbutton, . Units,normalized, . Position,btnPos, . String,labelStr, . Callback,callbackStr, . UserData,btnNumber m n pdflabel); %动画 switch pdflabel case 1 while(method=1) %画系x2分布密度函数 a=n/2; b=2; %画x2分布密度函数 x=xstart:0.1:xstart+width;y=gampdf(x,a,b); plot(x,y,b,EraseMode,normal); hold on %画近似正太分布密度函数 y1=normpdf(x,n,(2*n)0.5); plot(x,y1,r-); %图形参数调节 axis(xstart xstart+width 0 lenth); set(gca,XTick,xstart:xdis:xstart+width); set(gca,YTick,0:ydis:lenth); grid on; legend(X2分布,正态分布); %显示当前n temp=num2str(floor(n); str=strcat(n=,temp); text(92,0.2,str); %显示当前最大间距 dis=num2str(max(abs(y-y1); str=strcat(dis=,dis); text(92,0.187,str); %动画指令 drawnow; hold off n=n+speed; %看stop是否按下 data=get(gco,UserData); method=data(1); %更新传递参数 set(conthld,UserData,btnNumber m n pdflabel); end case 2 while(method=1) x=-width:0.1:width;y=tpdf(x,n); plot(x,y,EraseMode,normal); hold on %画近似正太分布密度函数 y1=normpdf(x,0,(n/(n-2)0.5); plot(x,y1,r-); %图形参数调节 axis(-width width 0 lenth); set(gca,XTick,-width:xdis:width); set(gca,YTick,0:ydis:lenth); grid on; legend(T分布,正态分布); %显示当前n temp=num2str(floor(n); z=strcat(n=,temp); text(3.3,0.335,z); %显示当前最大间距 dis=num2str(max(abs(y-y1); str=strcat(dis=,dis); text(3.3,0.315,str); %动画指令 drawnow; hold off n=n+speed; %看stop是否按下 data=g