1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Notation (index notation)

  1. Mar 18, 2016 #1
    I am having trouble converting [D]=[A][ B]T[C] to index notation.
    I initially thought it would be Dij=AijBkjCkl but I have doubts that this is correct.

    Would anyone be able to elaborate on this?

  2. jcsd
  3. Mar 18, 2016 #2


    User Avatar
    Science Advisor

    Where did B come from?
  4. Mar 18, 2016 #3
    BT? It is the transpose of B.
  5. Mar 18, 2016 #4


    User Avatar
    Science Advisor

    Err, did you edit your post? I didn't see a B in your equation before. Anyways, nevermind.
  6. Mar 18, 2016 #5
    No I never editted the equation. Do you have any ideas?
  7. Mar 18, 2016 #6


    Staff: Mentor

    The OP had [B], which browsers treat as the start tag for bold fonts. That screwed up the equation. I edited the equation to fix that problem.
  8. Mar 19, 2016 #7


    User Avatar
    Science Advisor

    OK. Let us start at the right. First: [itex]B^{T}_{j,k}=B_{k,j} [/itex], so [itex] (B^{T}\circ C)_{j,l}=\sum _{k}B^{T}_{j,k}C_{k,l}[/itex]. Then inset A at the front in the same way: [itex]A\circ (B^{T}\circ C)_{i,l}=\sum _{j}A_{i,j}(\sum _{k}B^{T}_{j,k}C_{k,l}) [/itex].
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted