# LU Decomposition Calculator

## Decomposing a square matrix into a lower triangular matrix and an upper triangular matrix. Partial pivot with row exchange is selected. | |||

The row pivot information in LU decomposition is in one-dimensional array P. |

- Purpose of use
- checking my code for LU decompo

[1] 2019/03/23 14:47 Female / 20 years old level / High-school/ University/ Grad student / Useful /

- Purpose of use
- Check my own code

[2] 2019/03/06 08:46 Male / 20 years old level / High-school/ University/ Grad student / Very /

- Purpose of use
- Testing my own algorithm

[3] 2019/03/01 04:30 Male / 20 years old level / High-school/ University/ Grad student / Very /

- Purpose of use
- checking work

[4] 2019/02/15 12:53 Male / Under 20 years old / High-school/ University/ Grad student / A little /

- Comment/Request
- I need it to work with a 3x4 matrix

[5] 2019/02/15 04:13 Male / 20 years old level / High-school/ University/ Grad student / A little /

- Purpose of use
- quick validation

[6] 2019/02/12 19:03 Male / 20 years old level / High-school/ University/ Grad student / Very /

- Purpose of use
- university coursework checking

[7] 2019/02/08 03:41 Female / 20 years old level / High-school/ University/ Grad student / Useful /

- Purpose of use
- Check handwritten work.

[8] 2018/12/09 05:16 Male / Under 20 years old / High-school/ University/ Grad student / Useful /

- Purpose of use
- Ensure my hand-written decomposition process was done correctly.

[9] 2018/11/14 22:43 Male / 20 years old level / High-school/ University/ Grad student / Very /

- Purpose of use
- Just wanted to check to see if my results matched what the calculator said.
- Comment/Request
- Your calculator is wrong. I entered a matrix like this:

[1 2 3]

[4 5 6]

[7 8 9]. And it said that the LU decomposition was this:

L [1 0 0] U=....

[0.14 1 0]

[0.57 0 1]

That by itself is wrong, the correct answer is:

L=[1 0 0] U=..... You should figure out to see what's wrong with your algorithm.

[4 1 0]

[7 2 1] - from Keisan
- The result seems to be correct.

L

[1 0 0]

[0.14.. 1 0]

[0.57.. 0.5 1]

U

[7 8 9]

[0 0.85.. 1.71..]

[0 0 5.E-15]

LU =

[7 8 9]

[1 2 3]

[4 5 6]

(Partial pivot with row exchange P_i = [3 1 2])

[10] 2018/10/21 03:01 Male / 40 years old level / Self-employed people / Not at All /

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**The hyperlink to [LU Decomposition]**