cbellei / TDMAsolver.py
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| import numpy as np |
| ## Tri Diagonal Matrix Algorithm(a.k.a Thomas algorithm) solver |
| def TDMAsolver ( a , b , c , d ): |
| »’ |
| TDMA solver, a b c d can be NumPy array type or Python list type. |
| refer to http://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm |
| and to http://www.cfd-online.com/Wiki/Tridiagonal_matrix_algorithm_-_TDMA_(Thomas_algorithm) |
| »’ |
| nf = len ( d ) # number of equations |
| ac , bc , cc , dc = map ( np . array , ( a , b , c , d )) # copy arrays |
| for it in xrange ( 1 , nf ): |
| mc = ac [ it — 1 ] / bc [ it — 1 ] |
| bc [ it ] = bc [ it ] — mc * cc [ it — 1 ] |
| dc [ it ] = dc [ it ] — mc * dc [ it — 1 ] |
| xc = bc |
| xc [ — 1 ] = dc [ — 1 ] / bc [ — 1 ] |
| for il in xrange ( nf — 2 , — 1 , — 1 ): |
| xc [ il ] = ( dc [ il ] — cc [ il ] * xc [ il + 1 ]) / bc [ il ] |
| return xc |
cbellei / TDMAsolver.py
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| import numpy as np |
| ## Tri Diagonal Matrix Algorithm(a.k.a Thomas algorithm) solver |
| def TDMAsolver ( a , b , c , d ): |
| »’ |
| TDMA solver, a b c d can be NumPy array type or Python list type. |
| refer to http://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm |
| and to http://www.cfd-online.com/Wiki/Tridiagonal_matrix_algorithm_-_TDMA_(Thomas_algorithm) |
| »’ |
| nf = len ( d ) # number of equations |
| ac , bc , cc , dc = map ( np . array , ( a , b , c , d )) # copy arrays |
| for it in xrange ( 1 , nf ): |
| mc = ac [ it — 1 ] / bc [ it — 1 ] |
| bc [ it ] = bc [ it ] — mc * cc [ it — 1 ] |
| dc [ it ] = dc [ it ] — mc * dc [ it — 1 ] |
| xc = bc |
| xc [ — 1 ] = dc [ — 1 ] / bc [ — 1 ] |
| for il in xrange ( nf — 2 , — 1 , — 1 ): |
| xc [ il ] = ( dc [ il ] — cc [ il ] * xc [ il + 1 ]) / bc [ il ] |
| return xc |
cbellei / TDMAsolver.py
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
| import numpy as np |
| ## Tri Diagonal Matrix Algorithm(a.k.a Thomas algorithm) solver |
| def TDMAsolver ( a , b , c , d ): |
| »’ |
| TDMA solver, a b c d can be NumPy array type or Python list type. |
| refer to http://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm |
| and to http://www.cfd-online.com/Wiki/Tridiagonal_matrix_algorithm_-_TDMA_(Thomas_algorithm) |
| »’ |
| nf = len ( d ) # number of equations |
| ac , bc , cc , dc = map ( np . array , ( a , b , c , d )) # copy arrays |
| for it in xrange ( 1 , nf ): |
| mc = ac [ it — 1 ] / bc [ it — 1 ] |
| bc [ it ] = bc [ it ] — mc * cc [ it — 1 ] |
| dc [ it ] = dc [ it ] — mc * dc [ it — 1 ] |
| xc = bc |
| xc [ — 1 ] = dc [ — 1 ] / bc [ — 1 ] |
| for il in xrange ( nf — 2 , — 1 , — 1 ): |
| xc [ il ] = ( dc [ il ] — cc [ il ] * xc [ il + 1 ]) / bc [ il ] |
| return xc |
A = np.array([[10,2,0,0],[3,10,4,0],[0,1,7,5],[0,0,3,4]],dtype=float) a = np.array([3.,1,3]) b = np.array([10.,10.,7.,4.]) c = np.array([2.,4.,5.]) d = np.array([3,4,5,6.]) print TDMAsolver(a, b, c, d) >> [ 0.14877589 0.75612053 -1.00188324 2.25141243] #compare against numpy linear algebra library print np.linalg.solve(A, d) >> [ 0.14877589 0.75612053 -1.00188324 2.25141243]
cbellei / TDMAsolver.py
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
| import numpy as np |
| ## Tri Diagonal Matrix Algorithm(a.k.a Thomas algorithm) solver |
| def TDMAsolver ( a , b , c , d ): |
| »’ |
| TDMA solver, a b c d can be NumPy array type or Python list type. |
| refer to http://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm |
| and to http://www.cfd-online.com/Wiki/Tridiagonal_matrix_algorithm_-_TDMA_(Thomas_algorithm) |
| »’ |
| nf = len ( d ) # number of equations |
| ac , bc , cc , dc = map ( np . array , ( a , b , c , d )) # copy arrays |
| for it in xrange ( 1 , nf ): |
| mc = ac [ it — 1 ] / bc [ it — 1 ] |
| bc [ it ] = bc [ it ] — mc * cc [ it — 1 ] |
| dc [ it ] = dc [ it ] — mc * dc [ it — 1 ] |
| xc = bc |
| xc [ — 1 ] = dc [ — 1 ] / bc [ — 1 ] |
| for il in xrange ( nf — 2 , — 1 , — 1 ): |
| xc [ il ] = ( dc [ il ] — cc [ il ] * xc [ il + 1 ]) / bc [ il ] |
| return xc |
cbellei / TDMAsolver.py
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
| import numpy as np |
| ## Tri Diagonal Matrix Algorithm(a.k.a Thomas algorithm) solver |
| def TDMAsolver ( a , b , c , d ): |
| »’ |
| TDMA solver, a b c d can be NumPy array type or Python list type. |
| refer to http://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm |
| and to http://www.cfd-online.com/Wiki/Tridiagonal_matrix_algorithm_-_TDMA_(Thomas_algorithm) |
| »’ |
| nf = len ( d ) # number of equations |
| ac , bc , cc , dc = map ( np . array , ( a , b , c , d )) # copy arrays |
| for it in xrange ( 1 , nf ): |
| mc = ac [ it — 1 ] / bc [ it — 1 ] |
| bc [ it ] = bc [ it ] — mc * cc [ it — 1 ] |
| dc [ it ] = dc [ it ] — mc * dc [ it — 1 ] |
| xc = bc |
| xc [ — 1 ] = dc [ — 1 ] / bc [ — 1 ] |
| for il in xrange ( nf — 2 , — 1 , — 1 ): |
| xc [ il ] = ( dc [ il ] — cc [ il ] * xc [ il + 1 ]) / bc [ il ] |
| return xc |