包含参数的函数积分问题
本帖最后由 牛小贱 于 2014-3-7 11:02 编辑程序： clear all;
syms x t
y=real(exp(-x.^2).*conj(exp(-(x+t).^2).*exp(-i.*2.*pi.*(192.31.*t+10.*x))));>>y=subs(y,t,-5);
int=int(y,x,-inf,inf)
Warning: Explicit integral could not be found.
int =
int(exp(2*pi*(10*conj(x) - 19231/20)*i)/(2*exp((conj(x) - 5)^2)*exp(x^2)) + (1/exp(2*pi*(10*x - 19231/20)*i))/(2*exp((x - 5)^2)*exp(conj(x)^2)), x = -Inf..Inf)
积分为什么没结果？
求指教啊。。 看提示：Explicit integral could not be found
函数积分无解析解 犟牛 发表于 2014-3-7 10:52
看提示：Explicit integral could not be found
函数积分无解析解
对函数积分完以后得到的不应该是对应的数值吗 为什么说是无解析解呢。 请看清楚，你用的是符号积分
包含复数的数值积分。。
想求这个积分：data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAARkAAAA3CAYAAAA4wT7lAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAlASURBVHhe7Z0xduI8EMeH7yyQgscJnBNAmlS06aAkTTrKdNtAGTraVGkWTgAnyKPA3MXfjGQb2ZZtyVi2Wea3z5tAjPHMSH+NZMnuBQgwDMM44r/wJ8MwjBNYZBiGcQqLDMMwTmGRYRjGKSwyDMM4hUWGYRinsMgwDOMUFhmGYZzCIsMwjFNYZBiGcUqtIrOf96DXw+15DRf8t34OX+P2vL6EezEM80jUJzL7OXwOfaClUMHyBIPeAN6PHqx8fI3vbeEN5vtw31bZw5yFryLsO8aeSiITZyy4RcJxOQ9huejLF+Mv2M0AvNUWorf6iyUMz+0XzMv6DK8khMEORu9vwHXFHPYdUwVrkSGBmWzCF8hmMsf2Lc0efjYeTF9ChekQ/cUCxuK3MbyiEDLmsO+YKtiJzGUNn4rASH6BEpT+0wk+w6btsv4E1Bj4fqOxGQm9d3rqkuigEMIyzrTuhcv62XlXpfw7uuG7xHli2XzuPWuyq2sXT44VKmAXP8rIe3X25XPPRRmnTJ9LCfXEnXyhSwocQ/eTMcVfeQH2gQIff8fuEN2HJoDZTv4REX+n98ALVnKn8DUEnnijO/irVXA98/tA+Ffxd334wWqVPC7FNy9mTftOLXcRCV/E5SwsdzFolwfBdTelvPqrwFN/zy2jWd8UknsuSZ9WiWVRTIrZBZh4oh/Qlhn6UZzjrLEYWolMIkh3DAVYBmuHBahK0FqACoYr3+OxdYWX4p3+yk74TusLqkipik37JcTpuo+/22VFKyVkghzfFKM5FyFkasWmfewrui4mpoj6SwLYcB22EBnZKmgD0SFEYVFaJeFY5ZxjR4fbLf72V7NMa+WGZIscUWZrAqwsWVtlC5frC6oYjnxnDAkFfV/8ZXpfSFuSFTsrHHmfRbSCVGKr1qeERmQyx8+ei1E8UzHJHleHtOUOMpnQ6aUGdYAwEDsMmr4Q3Ir0hX0LV5FMK6hgamtehUgX2gSaytICVNnic8/1RU7FTuybLzJUwTPxLPQNkudTzbkIAUnsnHMupfHU2Cl8YhIn+uwt4kKfJ9G1O4b9JezjCfzw187Sf4EpvMMnbOFLXg6pDzGo9yMu5R6aGvn0T3D0hjAIXya40dbL3284jp5Ab8kAht4RTq0GnK5UzuA1sq3IF2kGQ/BgE1+QwA/D6ejBMPPhPfz5nsI2Fc9i3ziiNJ6amPQXcAi2AG/XKSV6xvAVfIVXCC0QZZ4GrCfoTWT2anWM+ibjNYA6PyezJbzbh6cRwKj2q1l7mA++YepXCFQO5jblkW9r4tiTDWwmyuvw2P7piGWmLmvMMbZ7/wMby0IdQ5UP06Dj+yA8NlYSbwrpmRX7OTYah0VGTHS+MfGpjj4F6fdscEWpatntw+KwA5jormrdiBCxADAbEy9ty0sFkZGXrNtg/CW6d/otIft7OP9iG/ZjUknN2c8n8KtMMKwDc5vyyLc1cWysbJh+p46dyhIaxNTu/c/mNhEcf8XHRRfAbJkUE7o0/POqazT0vin3aQ6UVam9gMtf+D7qfH9L2cVMZTeCd2XqSJ2Q6ALmhtlMsBhzkbmcUV7uA2qZnrZT8KjlwFRvXYfW7OcwwUIXz2puknQBVbjJVsoSCrseed2LptBU9AJf5CPnp9Cyl2RbNIc3tVuCr+NkpNQ3lmA2sJxdu27UFYPVR0bcyuNZEpPxB6ywu/VWezpDscAfmkywFFRgM8TgUsFIeweIRufl+cmBtboGqmnwsbGB3gz5VyKMbdUMUkbHyB3IKxv4dE1c5tRBTc2AqVI2E+VTDPymPy+52q5uVz+U+obQDfzmnYsgjBP9LfVB43gaxEQcq+64hb6sUge6JzJxwYi2W0bD60KOqle2uw6b6BgNV3gS1ptj7SKeLfiiKxjFRPjc5GpTDgmhlMeh71WPGYliWnTkfrgpJ9khkdFcHou+080XmiPOo0rQ6rVJBLYhX9yeubmNZ5O+6ArGMQn9bO+eKNNSy3oUR9xI2KMYxlsUXyVLi/YV79uIjNIi1d5tyCt8NRbKmxDnYSkyrmzCONTu/xRUgW/6jqbi2YAvuoJdTKpk3ppGIUSftVxFhb6nSAA7IDLRyWaNS6dorWEtMndgkzMe2faOEIq5ucgkBSNNbtwMNaF1kYlUMm2cNKxuQauKXctwHza54ZFt7wyWjWIUM32GGQqQdgwszH5KxsdaFplsqxcVxq61eHReZnbfj03188i2dwcpGtlMUk/UTcqJT1jv88q+jG9xbNsVmaiPrm6m6ULTkP0mVzTuyaa6eWTbO4MUDeM6GtVrbZxKBCj+e/H3tbusgNah0M/ZjsRObkWzJtuEbik6MpjkdE821c0j294RxA3jwHzS6OUsp9h6mtl9+/kn/GKrkTcBT9yO1V8B7XIsWOBmLjJisVnNRMfMW9NBdy6zvIOYS8ZfPky/B8WL0O7Mplp5ZNu7APp38A6wqmFtnVhuMZyiepDGvGTWddGiyT/wAmNa0ElB3/xAPFl6nYoxtjZmKKlwbd0lJO6zJ9K1sG/fVqod26pLE+ncivugnbSpIR7Z9lYRZba4XGqJyroyFEAxpDp+HcTHbhHGTsRW7Ievlf3VwX7aJx3mSiJTd1mJC2a8VXBWnRSKDCErTZEfOmdTgzyy7a1gOl6YQ3x1Kdzich2Pw8pB5GtcU4PKJdrQo//wj+XQPSUwF6M+Nx6o/vu03CG07P/nlX3BtAd1awanZafHvu7qfjJdg5b9s8AwbdJfHDo/uG4uMv0nGIW/MgzDmMKZDMMwTrEQGbq3KP1s8yZGDMPcG5zJMAzjFAuRkTc4rkJ882UxEUt5VCdurh+5yjBMu1hlMgPRXxqB1Y3U93Nxb1W6Uh4sTzDoDeD96MHKl9POt/BW8hgHhmHuGfvukuXNlS/n4XUdBa3/meEhlDv+9xdLGLb1+AOGYZxTKDI00Ud2a+bxugRQHnZl/OycGLrjuQdT69udMwxzrxTM+N3DPHpinIL1bF/sLj2fP8TTFsXsxG+6PjWFbfgwLXrvz9OBJ7UxzD9KQSYTXbJW8FbwYSsG2EWicRfKbsQK0e0BDmJsRmY8iefeMAzzz1G8domW5k/CXAYFxtc8ypNhGKYI8wWSDMMwFbC/usQwDGMBiwzDME5hkWEYxiksMgzDOIVFhmEYhwD8DxRKG42qBmIUAAAAAElFTkSuQmCCt是参数，取对应一组值。
程序：
clear all;
syms x t
>> y=exp(-x.^2).*conj(exp(-(x+t).^2).*exp(-i.*2.*pi.*(192.31.*t+10.*x)));
>> a=-5:1:5;
>> y=subs(y,t,a);
>> int=int(y,x,-inf,inf);
Warning: Explicit integral could not be found.
求指教。。
实际想求的是这样一个积分（下面图片中的函数）
t取对应一组值。
程序clear all;
syms x t
>> y=exp(-x.^2).*conj(exp(-(x+t).^2).*exp(-i.*2.*pi.*(192.31.*t+10.*x)));
>> a=-5:1:5;
>> y=subs(y,t,a);
>> int=int(y,x,-inf,inf);
Warning: Explicit integral could not be found.
>> in=quad(y,x,-inf,inf);
??? Error using ==> fcnchk at 108
If FUN is a MATLAB object, it must have an feval method.
Error in ==> quad at 66
f = fcnchk(funfcn);
用符号积分和数值积分同样有错误。。
犟牛 发表于 2014-3-7 11:19
请看清楚，你用的是符号积分
实际想求的是这样一个积分（下面图片中的函数）
t取对应一组值。
程序clear all;
syms x t
>> y=exp(-x.^2).*conj(exp(-(x+t).^2).*exp(-i.*2.*pi.*(192.31.*t+10.*x)));
>> a=-5:1:5;
>> y=subs(y,t,a);
>> int=int(y,x,-inf,inf);
Warning: Explicit integral could not be found.
>> in=quad(y,x,-inf,inf);
??? Error using ==> fcnchk at 108
If FUN is a MATLAB object, it must have an feval method.
Error in ==> quad at 66
f = fcnchk(funfcn);
用符号积分和数值积分同样有错误。。 shuill 发表于 2014-3-7 11:46
实际想求的是这样一个积分（下面图片中的函数）
t取对应一组值。
程序clear all;
数值积分错误那是你的命令使用有问题
quad中的被积函数应该以函数句柄的形式给出
建议好好看一下相关帮助吧，参照帮助里的例子来写，不难
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