partial differentating a matrix by a vector

Hi guys,

I want to comute ,

where M is a symbolic matrix , and A is a symbolic vector. Are there any commands in Matlab can make it?

Many thanks!

Answer 1

[Bjorn Gustavsson]

Have a look at the help and documentation for jacobian.

HTH

[Tony Cheng]

Hey man, thx for ur adivce! However, jacobian is about two vectors. What I want is about one matrix and one vector.

[Bjorn Gustavsson]

My bad, but: Same difference. What you ask for would then be something like the combined Jacobians for each row of your input matrix, how, you'd go about storing those differentials is for you to chose, and will depend on what you need to do with them. Sometimes I prefer using 3-D arrays. Sometimes it is beneficial to use 1 and 2-D arrays for neat matrix-multiplications, then it is easy to convert matrices to column-vectors using:

V = M(:);

Then you've straightened out your matrix to a vector where you can directly use jacobian, after that you might want to reshape it to suit your needs.

HTH

[Tony Cheng]

Hi Bjorn, Thx so much forur great detailed description! I see how to use jacobian now! Your answer really helps a lot!

[Bjorn Gustavsson]

Thanks, I'm happy to have contributed.