Confusing about LU factorization process.

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Why does y = Ux. Where does this even come from?



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  • You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
    – JMoravitz
    Aug 3 at 1:30














up vote
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down vote

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Why does y = Ux. Where does this even come from?



enter image description here




linear-algebra




share|cite|improve this question



















  • You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
    – JMoravitz
    Aug 3 at 1:30












up vote
0
down vote

favorite









up vote
0
down vote

favorite











Why does y = Ux. Where does this even come from?



enter image description here




linear-algebra




share|cite|improve this question











Why does y = Ux. Where does this even come from?



enter image description here





linear-algebra





share|cite|improve this question










share|cite|improve this question




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asked Aug 3 at 1:17









Jwan622

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  • You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
    – JMoravitz
    Aug 3 at 1:30
















  • You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
    – JMoravitz
    Aug 3 at 1:30















You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
– JMoravitz
Aug 3 at 1:30




You asked the exact same question here. Please... be patient and wait for responses on the first time you ask the question rather than posting again.
– JMoravitz
Aug 3 at 1:30










1 Answer
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If $boldsymbol A = boldsymbol LU$, then the equation $boldsymbol Ax = boldsymbol b$ could be written as $boldsymbol LUx = boldsymbol b$. To solve this equation, we first let $boldsymbol y = boldsymbol Ux$, then we can first solve $boldsymbol y$ from $boldsymbol Ly = boldsymbol b$, then solve $boldsymbol x$ from $boldsymbol Ux = boldsymbol y$.






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  • @JMoravitz thanks for pointing out.
    – xbh
    Aug 3 at 1:28










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
2
down vote



accepted










If $boldsymbol A = boldsymbol LU$, then the equation $boldsymbol Ax = boldsymbol b$ could be written as $boldsymbol LUx = boldsymbol b$. To solve this equation, we first let $boldsymbol y = boldsymbol Ux$, then we can first solve $boldsymbol y$ from $boldsymbol Ly = boldsymbol b$, then solve $boldsymbol x$ from $boldsymbol Ux = boldsymbol y$.






share|cite|improve this answer























  • @JMoravitz thanks for pointing out.
    – xbh
    Aug 3 at 1:28














up vote
2
down vote



accepted










If $boldsymbol A = boldsymbol LU$, then the equation $boldsymbol Ax = boldsymbol b$ could be written as $boldsymbol LUx = boldsymbol b$. To solve this equation, we first let $boldsymbol y = boldsymbol Ux$, then we can first solve $boldsymbol y$ from $boldsymbol Ly = boldsymbol b$, then solve $boldsymbol x$ from $boldsymbol Ux = boldsymbol y$.






share|cite|improve this answer























  • @JMoravitz thanks for pointing out.
    – xbh
    Aug 3 at 1:28












up vote
2
down vote



accepted







up vote
2
down vote



accepted






If $boldsymbol A = boldsymbol LU$, then the equation $boldsymbol Ax = boldsymbol b$ could be written as $boldsymbol LUx = boldsymbol b$. To solve this equation, we first let $boldsymbol y = boldsymbol Ux$, then we can first solve $boldsymbol y$ from $boldsymbol Ly = boldsymbol b$, then solve $boldsymbol x$ from $boldsymbol Ux = boldsymbol y$.






share|cite|improve this answer















If $boldsymbol A = boldsymbol LU$, then the equation $boldsymbol Ax = boldsymbol b$ could be written as $boldsymbol LUx = boldsymbol b$. To solve this equation, we first let $boldsymbol y = boldsymbol Ux$, then we can first solve $boldsymbol y$ from $boldsymbol Ly = boldsymbol b$, then solve $boldsymbol x$ from $boldsymbol Ux = boldsymbol y$.







share|cite|improve this answer















share|cite|improve this answer



share|cite|improve this answer








edited Aug 3 at 1:28


























answered Aug 3 at 1:24









xbh

1,0006




1,0006











  • @JMoravitz thanks for pointing out.
    – xbh
    Aug 3 at 1:28
















  • @JMoravitz thanks for pointing out.
    – xbh
    Aug 3 at 1:28















@JMoravitz thanks for pointing out.
– xbh
Aug 3 at 1:28




@JMoravitz thanks for pointing out.
– xbh
Aug 3 at 1:28












 

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