【如何将符号函数转换为矩阵函数例如pdx1=pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)如何将其转换成向量函数?sym2poly只能转换含有单一变量的函数在线等一共20积分都送出去了,请别嫌弃】
如何将符号函数转换为矩阵函数
例如pdx1=pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)
如何将其转换成向量函数?sym2poly只能转换含有单一变量的函数
在线等
一共20积分都送出去了,请别嫌弃
命令就是下面的,coeffs（）
>>symsx1x2;
>>pdx1=pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)
pdx1=
pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)
>>coeffs(pdx1)
ans=
[1,1]
>>coeffs(pdx1,x1)
ans=
[pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)]
>>coeffs(pdx1,x2)
ans=
[pi*cos(pi*x1)+pi*cos(pi*x1)*cos(pi*x2)]
matlab解释
COEFFSCoefficientsofamultivariatepolynomial.
C=COEFFS(P)returnsthecoefficientsofthepolynomialPwith
respecttoalltheindeterminatesofP.
C=COEFFS(P,X)returnsthecoefficientsofthepolynomialPwith
respecttoX.
[C,T]=COEFFS(P,...)alsoreturnsanexpressionsequenceofthe
termsofP.Thereisaone-to-onecorrespondencebetweenthe
coefficientsandthetermsofP.
Examples:
symsx
t=2+(3+4*log(x))^2-5*log(x);
coeffs(expand(t))=[11,19,16]
symsabcx
y=a+b*sin(x)+c*sin(2*x)
coeffs(y,sin(x))=[a+c*sin(2*x),b]
coeffs(expand(y),sin(x))=[a,b+2*c*cos(x)]
symsxy
z=3*x^2*y^2+5*x*y^3
coeffs(z)=[5,3]
coeffs(z,x)=[5*y^3,3*y^2]
[c,t]=coeffs(z,y)returnsc=[5*x,3*x^2],t=[y^3,y^2]