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irongreat
Jul12-08, 09:24 AM
I've written a program in c language in terms of the GR SVD algorithm. To my dispointment,its performance is worse than the svd of matlab. I wish to get to know which algorithm the matlab used. Who may tell me? Thanks.

shoehorn
Jul12-08, 11:45 AM
I've written a program in c language in terms of the GR SVD algorithm. To my dispointment,its performance is worse than the svd of matlab. I wish to get to know which algorithm the matlab used. Who may tell me?

Matlab will.

doc svd

irongreat
Jul12-08, 10:03 PM
Oh, you said nothing.

shoehorn
Jul13-08, 05:16 AM
Oh, you said nothing.

No, I told you that if you had had the startlingly obvious idea to check the documentation for svd in Matlab, you'd find which algorithms it uses to compute singular value decompositions.

If you want to be snippy towards someone who's given you the answer to your question, that's your business.

irongreat
Jul13-08, 09:23 PM
You are not friendly,Shoehorn. I have read the matlab document. I know it use DGESVD. But I cannot find the details of the algorithm. So I asked the question.
Do take any thing for granted. Ok? GUY

irongreat
Jul13-08, 09:27 PM
As a matter of fact ,I have found the source code of the algorithm. But I wonder the cause of its fast speed.So I hope to find the primitive document about the algorithm.
Who may tell me?

las3rjock
Jul13-08, 11:57 PM
Oh, you said nothing.
Actually, shoehorn said everything. It was enough for you to figure out that, for real-valued matrices, MATLAB uses the DGESVD routine from LAPACK. That should have been enough of a clue for you to find the LAPACK Users' Guide (http://www.netlib.org/lapack/lug/), and specifically the section entitled Singular Value Decomposition (http://www.netlib.org/lapack/lug/node53.html), which is probably what you were looking for.

shoehorn
Jul14-08, 08:52 AM
You are not friendly,Shoehorn. I have read the matlab document. I know it use DGESVD.... So I asked the question.

So you know which algorithm Matlab uses for singular value decompositions, and yet you still decided to waste everyone's time by asking which algorithm Matlab uses for singular value decompositions?

Matlab has the best documentation of any software I've ever seen. Ever. Learn how to use it. 90% of the questions about Matlab on this forum are from people who are too lazy to read the documentation and instead want to waste other people's time by getting them to do work that they are too lazy/stupid to perform.

irongreat
Jul14-08, 10:08 PM
So you know which algorithm Matlab uses for singular value decompositions, and yet you still decided to waste everyone's time by asking which algorithm Matlab uses for singular value decompositions?

Matlab has the best documentation of any software I've ever seen. Ever. Learn how to use it. 90% of the questions about Matlab on this forum are from people who are too lazy to read the documentation and instead want to waste other people's time by getting them to do work that they are too lazy/stupid to perform.

Don't insult me,ok? I only implement sth not by matlab.
If I used matlab, I not ask the question.

Matlab is a good software, but it is too large , I cannot put it into a hardware. So I have to implement svd by myself.

irongreat
Jul14-08, 10:10 PM
I have to research linpack source code. It is more complicated than read the primitive document.

Sigh.

irongreat
Jul14-08, 10:12 PM
I dislike those who take themselves as industrious men.
Is it a a great thing to develop sth on matlab?