作业帮MATLAB符号表达式赋值问题!syms x;A=zeros(9,9);B=[x^5,x^3,x;3*x^2,4,7*x^4;5,7,1]; A(1:3,1:3)=B;可以实现,但A(1:3,1:3)=A(1:3,1:3)+B;就不行,错误报告如下：The following error occurred converting from sym to double:Error using ==> mu
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![MATLAB符号表达式赋值问题!syms x;A=zeros(9,9);B=[x^5,x^3,x;3*x^2,4,7*x^4;5,7,1]; A(1:3,1:3)=B;可以实现,但A(1:3,1:3)=A(1:3,1:3)+B;就不行,错误报告如下：The following error occurred converting from sym to double:Error using ==> mu](/uploads/image/z/554638-22-8.jpg?t=MATLAB%E7%AC%A6%E5%8F%B7%E8%A1%A8%E8%BE%BE%E5%BC%8F%E8%B5%8B%E5%80%BC%E9%97%AE%E9%A2%98%21syms+x%3BA%3Dzeros%289%2C9%29%3BB%3D%5Bx%5E5%2Cx%5E3%2Cx%3B3%2Ax%5E2%2C4%2C7%2Ax%5E4%3B5%2C7%2C1%5D%3B+A%281%3A3%2C1%3A3%29%3DB%3B%E5%8F%AF%E4%BB%A5%E5%AE%9E%E7%8E%B0%2C%E4%BD%86A%281%3A3%2C1%3A3%29%3DA%281%3A3%2C1%3A3%29%2BB%3B%E5%B0%B1%E4%B8%8D%E8%A1%8C%2C%E9%94%99%E8%AF%AF%E6%8A%A5%E5%91%8A%E5%A6%82%E4%B8%8B%EF%BC%9AThe+following+error+occurred+converting+from+sym+to+double%3AError+using+%3D%3D%3E+mu)
MATLAB符号表达式赋值问题!syms x;A=zeros(9,9);B=[x^5,x^3,x;3*x^2,4,7*x^4;5,7,1]; A(1:3,1:3)=B;可以实现,但A(1:3,1:3)=A(1:3,1:3)+B;就不行,错误报告如下：The following error occurred converting from sym to double:Error using ==> mu
MATLAB符号表达式赋值问题!
syms x;
A=zeros(9,9);B=[x^5,x^3,x;3*x^2,4,7*x^4;5,7,1];
A(1:3,1:3)=B;可以实现,但
A(1:3,1:3)=A(1:3,1:3)+B;就不行,错误报告如下：
The following error occurred converting from sym to double:
Error using ==> mupadmex
Error in MuPAD command:DOUBLE cannot convert the input expression into a double array.
If the input expression contains a symbolic variable,use the VPA function instead.
MATLAB符号表达式赋值问题!syms x;A=zeros(9,9);B=[x^5,x^3,x;3*x^2,4,7*x^4;5,7,1]; A(1:3,1:3)=B;可以实现,但A(1:3,1:3)=A(1:3,1:3)+B;就不行,错误报告如下：The following error occurred converting from sym to double:Error using ==> mu
我这里matlab试的时候,A(1:3,1:3)=A(1:3,1:3)+B;也不能实现.
原因是A是double类型的,而B是sym类型的.
A没能够实现强制转换.
可以这样：
A1= A(1:3,1:3);
A1=B;
A1=A1+B;