LU Decomposition and Partial Pivoting

[@ghostrs3824]

For those confused: dummy and idx were used as storing variables and are both defined as Max(col1) where the value would be the row with the largest number. He messed up around 15:00 and put max(col1) instead of max(col2) but he quickly fixed it

[@TheProPeeL]

Simply swapping the rows gives you no guarantee that L*U will return the starting matrix, so I'm guessing you just got lucky with the result

[@AGnanaprakasam]

around 11.27 minutes, Small part of the video is missing

[@onesteptowardssuccess9928]

I don't understand how raw exchange is done by idx and dummy

[@vkg5900]

For line 28 and 29 Use 'idx+1' instead of 'idx'

[@shubhankarsarkar1995]

I think there's some issue with partial pivoting part of the code. Can anyone suggest how to do it correctly?

[@passionofsimulation3005]

Hi guys actually there is an error in idx for pivot element A(2,2). Col2 is a 2X1 matrix of -1.667 & - 0.333. Idx for A(2,2) will take position of max value of Col2 which will be -0.333. Hence idx will be 2. But when you pass this idx for Ab matrix, there will be no row interchange between Row 2 & Row 3 and Row 2 remains unchanged. Still Ab matrix is same without any row exchange which is wrong.

[@vkg5900]

Yes, U r right

[@sangepuleelasaikiran5815]

What is meant by idx

[@chandangupta-uu3hr]

index

[@prasenjit8741]

partial pivoting portion is incorrect increasing confusion. idx?? not clearly explained

[@subhadeep_2001]

Too much confusion