Jacobian function not found

2011 10 10
2 个回答
回答已采纳
6 次查看（30 天）

0 个投票

Hello to all,
I have to use the "jacobian" function in Matlab. I have the Symbolic toolbox installed, but upon running jacobian(a, b), the prompt tells me :
??? Undefined function or variable 'jacobian'.
What should I do?
Best regards,
Jean

请先登录，再回答此问题。

 采纳的回答

Wayne King
Wayne King 2011-10-10

0 个投票

If you enter
>>ver
Do you see an entry for the Symbolic Toolbox?
If you enter:
license('test','symbolic_toolbox')
Do you get a 1 back? You may think you installed it, but perhaps something went wrong.

8 个评论
显示 6更早的评论 隐藏 6更早的评论

Jean
Jean 2011-10-15
Hello Wayne,
the license test outputs zero, although the people in my department told me we have full matlab and symulink. I can actually see in the toolbox tab the "Symbolic Math" entry, but I do not understand why I cannot use this function.
Walter Roberson
Walter Roberson 2011-10-16
If the license test outputs 0 then you either do not have the toolbox installed or you do not have a license for it. Sometimes the situation is that it is installed but the version installed does not match the MATLAB version.
If you use the command
ver
then you should be able to see the list of installed software and the version numbers.
One situation that crops up from time to time is that people install everything that comes with the installation CD, and have access to those functions during the demo period, but then when an actual license is installed, lose access to the additional toolboxes because no license was purchased for the toolboxes.
Karen
Karen 2011-12-5
I do have the same problem with 2011a, jacobian is unknown even though my check for the toolbox resulted in "1"
Any suggestions?
Walter Roberson
Walter Roberson 2011-12-5
What error message do you get, Karen?
What does
which -all jacobian
report ?
Karen
Karen 2011-12-5
this is what I get:
>> jacobian
??? Undefined function or variable 'jacobian'.
>> license('test','symbolic_toolbox')
ans =
1
Karen
Karen 2011-12-5
and here is what your request got me:
which -all jacobian
/Applications/MATLAB_R2011a.app/toolbox/symbolic/symbolic/@sym/jacobian.m % sym method
Walter Roberson
Walter Roberson 2011-12-5
jacobian is a method of the symbolic class, so you have to invoke it with a symbolic argument for it to be located.
For example,
jacobian(sym('x^2+3*x*y-y^3'))
Karen
Karen 2011-12-5
got it :) Thanks!

请先登录，再进行评论。

更多回答（1 个）

Walter Roberson
Walter Roberson 2011-10-10

0 个投票

Which version are you using? I trace the function back at least as far as R14

类别

在 帮助中心 和 File Exchange 中查找有关 Introduction to Installation and Licensing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by