怎么画三维图呢,求助,万分感谢
如何用matlab画分段的三维图呢?可以帮我看一下下面这个例子,十分感谢!!!
例子:0<=x<=6;
0<=y<=4;
当0<=y<=1时,z=x-y;
当1<y<=3时,z=x+2y;
当3<y<=4时,z=x+y;
如何用matlab做出这种分段的三维图呢?
返回小木虫查看更多
今日热帖
如何用matlab画分段的三维图呢?可以帮我看一下下面这个例子,十分感谢!!!
例子:0<=x<=6;
0<=y<=4;
当0<=y<=1时,z=x-y;
当1<y<=3时,z=x+2y;
当3<y<=4时,z=x+y;
如何用matlab做出这种分段的三维图呢?
返回小木虫查看更多
你要把表达式用括号括起来,然后再点乘取值范围。就好像 z = (x-y).*(y>=0 & y<=1) + (x+2*y).*(y>1 & y<=3) + (x+y).*(y>3 & y<=4); 里面 x-y是表达式 后面点乘的是范围,后面同理。
我把你的程序稍微改了改,写在下面,附上图。顺便说一句点乘这种运算如果是数字就不需要用。
clear;
x = linspace(0,6,100);
t = linspace(0,0.4,100);
[x t] = meshgrid(x,t);
F1=(6.*(-38.59-33.33).*(- 360000./(29.*(29.*x - 210)) - 12000./203)-(6.*(-38.55-33.33).* 285.7143).*(108000000./(29.*(29.*x - 210).^2) ...
- 120000./1421)./2789.1).*0.3-(2.5.*9.81.*6+245).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1+245+2.5.*9.81.*x;
F2=(6.*(-(-4*pi^2*0.004*2.5.^2*10*(t-0.07).^2./(0.8^2)+pi.^2*0.004*2.5.^2./(10*0.8.^2))*1000-33.33).*(- 360000./(29.*(29.*x - 210)) ...
- 12000./203)-(6.*(-(-4*pi^2*0.004*2.5.^2*10*(t-0.07).^2./(0.8^2)+pi.^2*0.004*2.5.^2./(10*0.8.^2))*1000-33.33).* 285.7143)...
.*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1).*0.3-(2.5.*9.81.*6+245).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1+245+2.5.*9.81.*x;
F3=(6.*((2*pi*0.004*2.5*cos(2*pi*2.5*(0.2-t)./0.8)./0.8)*1000-33.33).*(- 360000./(29.*(29.*x - 210)) - 12000./203)...
-(6.*((2*pi*0.004*2.5*cos(2*pi*2.5*(0.2-t)./0.8)./0.8)*1000-33.33).* 285.7143).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1)...
.*0.3-(2.5.*9.81.*6+245).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1+245+2.5.*9.81.*x;
F4=(6.*(-(-4*pi^2*0.004*2.5.^2*10*(t-0.33).^2./(0.8^2)+pi.^2*0.004*2.5.^2./(10*0.8.^2))*1000 -33.33).*(- 360000./(29.*(29.*x - 210)) ...
- 12000./203)-(6.*(-(-4*pi^2*0.004*2.5.^2*10*(t-0.33).^2./(0.8^2)+pi.^2*0.004*2.5.^2./(10*0.8.^2))*1000 -33.33).* 285.7143)...
.*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1).*0.3-(2.5.*9.81.*6+245).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1+245+2.5.*9.81.*x;
F5=(6.*(-38.59-33.33).*(- 360000./(29.*(29.*x - 210)) - 12000./203)-(6.*(-38.55-33.33).* 285.7143).*(108000000./(29.*(29.*x - 210).^2) ...
- 120000./1421)./2789.1).*0.3-(2.5.*9.81.*6+245).*(108000000./(29.*(29.*x - 210).^2) - 120000./1421)./2789.1+245+2.5.*9.81.*x;
f=F1.*(t<=0.07)+F2.*(0.07<t & t<=0.12)+F3.*(0.12<t & t<=0.28)+F4.*(0.28<t & t<=0.33)+F5.*(0.33<t & t<=0.4);
mesh(x,t,f)
untitled.jpg
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