请教高手:这几个语句中的jacobian是什么意思啊?

helloyy1020

f=x1^2+x1*x2+x2^2;
v=[x1,x2];
df=jacobian(f,v);
df=df.';

[ 本帖最后由 helloyy1020 于 2006-11-25 14:29 编辑 ]

eight

原帖由 helloyy1020 于 2006-11-25 14:28 发表
f=x1^2+x1*x2+x2^2;
v=;
df=jacobian(f,v);
df=df.';

Calculate Jacobian matrix for model at existing or new X points

Syntax
   J = Jacobian(model, optional X)

helloyy1020

好象不是特别明白啊

helloyy1020

明白了  谢谢

eight

原帖由 helloyy1020 于 2006-11-25 14:36 发表
好象不是特别明白啊

Jacobian matrix
Syntax
jacobian(f,v)

Description
jacobian(f,v) computes the Jacobian
of the scalar or vector f with respect to v.

Examples
f = [x*y*z; y; x+z];
v = [x,y,z];        
R = jacobian(f,v)

return
R =
[y*z, x*z, x*y]
[  0,   1,   0]
[  1,   0,   1]