[討論] quad積分問題已回收

看板MATLAB作者ycc01 (ycc01)時間14年前 (2011/05/19 14:22)推噓0(0推 0噓 3→)

留言3則, 2人參與討論串1/2 (看更多)

小弟是MATLAB新手，目前是看著書學KEY指令，最近學到積分的dblquad 指令，習題部分照著前面書中範例KEY，卻出現以下訊息，不是看的很懂?? dblquad('((4*y.^2)+1).^(0.5)',1,2*pi,0,1) ??? Error using ==> inline.subsref Too many inputs to inline function. Error in ==> dblquad>innerintegral at 78 fcl = intfcn(xmin, y(1), varargin{:}); %evaluate only to get the class below Error in ==> quad at 63 y = f(x, varargin{:}); Error in ==> dblquad at 58 Q = quadf(@innerintegral, ymin, ymax, tol, trace, intfcn, ... 但，試別的習題卻又可以算出來 dblquad('4*x.*(y<=log(x))',1,2,0,log(2)) ans = 2.5452 可是如果我只是把函數換成'1'，又出現這個訊息 dblquad('1',1,2,0,log(2)) ??? Error using ==> inline.subsref Too many inputs to inline function. Error in ==> dblquad>innerintegral at 78 fcl = intfcn(xmin, y(1), varargin{:}); %evaluate only to get the class below Error in ==> quad at 63 y = f(x, varargin{:}); Error in ==> dblquad at 58 Q = quadf(@innerintegral, ymin, ymax, tol, trace, intfcn, ... 但如果變成用triplequad 指令，函數是'1'，卻又可以算出 triplequad('1.*(y<=1-x & z>=x+y & z<=2-x-y )',0,1,0,1,0,2) ans = 0.3333 請問到底問題是什麼??要怎麼KEY才不會有問題?? -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 220.139.138.57

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math99

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ycc01

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