solve解一个方程​组时，怎样把变量名替​换为具体数据？。

solve解一个方程组时，怎样把变量名替换为具体数据；

首先定义了点xj的初始坐标xj=[1.4143 1.4143] 以及点xsumo[2 2];变量p0=0.5;

带入方程组求解，怎么接[qx qy]里仍然是xj（1），xj（2），怎样把它代替为矩阵中

的具体数值？

xj=[1.4143 1.414];

>> xsumo=[2 2];

>> p0=0.5;

>> [qx,qy]=solve('(qx-xj(1))*(qx-xsumo(1))+(qy-xj(2))*(qy-xsumo(2))=0','(qx-xsumo(1))^2+(qy-xsumo(2))^2=p0')

qx =

(p0 + xj(1)*xsumo(1) + xj(2)*xsumo(2) - xsumo(1)^2 - xsumo(2)^2 - (xj(2)*(xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2)))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2) + (xsumo(2)*(xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2)))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))/(xj(1) - xsumo(1))

(p0 + xj(1)*xsumo(1) + xj(2)*xsumo(2) - xsumo(1)^2 - xsumo(2)^2 - (xj(2)*(xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2)))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2) + (xsumo(2)*(xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2)))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))/(xj(1) - xsumo(1))

qy =

(xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2)

(xj(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) - xsumo(1)*(p0*(xj(1)^2 - 2*xj(1)*xsumo(1) - 2*xj(2)*xsumo(2) - p0 + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2))^(1/2) + p0*xj(2) - p0*xsumo(2) + xj(1)^2*xsumo(2) - 2*xj(2)*xsumo(2)^2 + xj(2)^2*xsumo(2) + xsumo(1)^2*xsumo(2) + xsumo(2)^3 - 2*xj(1)*xsumo(1)*xsumo(2))/(xj(1)^2 - 2*xj(2)*xsumo(2) - 2*xj(1)*xsumo(1) + xj(2)^2 + xsumo(1)^2 + xsumo(2)^2)

Answer 1

[josis]

xj=[1.4143 1.414];

xsumo=[2 2];

p0=0.5;

[qx,qy]=solve('(qx-xj(1))*(qx-xsumo(1))+(qy-xj(2))*(qy-xsumo(2))','(qx-xsumo(1))^2+(qy-xsumo(2))^2-p0','qx','qy')

qx=eval(qx)

qy=eval(qy)