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LU decomposition
- Thread starter hoshang
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- #21
That question has been answered several times now, both explicitly and implicitly
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
The question in the OP was:
The link previously posted:
has a good clear explanation of how to do LU decomposition, with and without pivoting, and why it is a good idea to use pivoting for general use, to avoid problems if there are any zeros on the leading diagonal. It also has Python code which will generate the unpivoted matrices (after applying corrections as posted above).
You haven't told us why you have to use the unpivoted matrices, or why it has to be done in Mathcad, but if both are essential for some reason, and if Mathcad doesn't have that as an option, it shouldn't be too hard to convert the Python code to Mathcad, or you could look at using:
or something similar.
Doug Jenkins
Interactive Design Services
to which the answer is:hoshang said:
IDS said:
The link previously posted:
has a good clear explanation of how to do LU decomposition, with and without pivoting, and why it is a good idea to use pivoting for general use, to avoid problems if there are any zeros on the leading diagonal. It also has Python code which will generate the unpivoted matrices (after applying corrections as posted above).
You haven't told us why you have to use the unpivoted matrices, or why it has to be done in Mathcad, but if both are essential for some reason, and if Mathcad doesn't have that as an option, it shouldn't be too hard to convert the Python code to Mathcad, or you could look at using:
or something similar.
Doug Jenkins
Interactive Design Services
I have now posted full Python code for solving with LU decomposition, with and without pivoting, at:
Doug Jenkins
Interactive Design Services
Doug Jenkins
Interactive Design Services
Thanks, do you know when you'll be posting the actual code?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
IRstuff - it should be in the next few days. There will also be functions to call the Scipy linear algebra functions from Excel.
Doug Jenkins
Interactive Design Services
Doug Jenkins
Interactive Design Services
Awesome, thanks
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
The Python code used in my posts in this thread, together with code to call the Scipy linear algebra functions from Excel, and a sample spreadsheet can be download from:
Note that calling the Python code from Excel requires the pyxll add-in.
Doug Jenkins
Interactive Design Services
Note that calling the Python code from Excel requires the pyxll add-in.
Doug Jenkins
Interactive Design Services
Thanks!
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
There is python library for LU decomposition.
It will probably run much faster than code you write yourself because scipy is really compiled C or Fortran code with a python wrapper.
Peter Nachtwey
Delta Computer Systems
IFPS Hall of Fame Member
It will probably run much faster than code you write yourself because scipy is really compiled C or Fortran code with a python wrapper.
Peter Nachtwey
Delta Computer Systems
IFPS Hall of Fame Member
PNatchwey said:
The great majority of the code in my link is for calling the Scipy linear algebra functions from Excel, including the LU decomposition functions.
The Python routines were written purely so I (and others) can see how the process works, in response to the question in the first post of this thread.
Also note that the download file includes links to the pyPardiso library which is very much faster than the Scipy LU functions.
Doug Jenkins
Interactive Design Services
- Thread starter
- #32
As said on 22nd May:
You haven't told us why you have to use the unpivoted matrices, or why it has to be done in Mathcad, but if both are essential for some reason, and if Mathcad doesn't have that as an option, it shouldn't be too hard to convert the Python code to Mathcad, or you could look at using:
or something similar.
Doug Jenkins
Interactive Design Services
You haven't told us why you have to use the unpivoted matrices, or why it has to be done in Mathcad, but if both are essential for some reason, and if Mathcad doesn't have that as an option, it shouldn't be too hard to convert the Python code to Mathcad, or you could look at using:
or something similar.
Doug Jenkins
Interactive Design Services
You CAN do this in Mathcad, albeit, a bit, or more, painfully
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
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