Matthew, I am probably not using the right language but I meant that each element has three indices associated with it: x, y, z.
Here is a snapshot: 1 10 55 5.7113635929515209e-03 1 10 56 4.2977490038287334e-03 1 10 57 2.8719519782193204e-03 1 10 58 1.4380140927001712e-03 1 10 59 9.9299930690365083e-17 1 11 0 0.0000000000000000e+00 1 11 1 1.5658614070601917e-03 1 11 2 3.1272842098367562e-03 1 11 3 4.6798423857521204e-03 Where the first three columns are the coordinates and the last one is value. Could you clarify the meaning of "diagonalization is not a clear concept" if it is applicable to this case. Thank you, -- Ketan On Mon, Jul 11, 2016 at 1:15 PM, Matthew Knepley <[email protected]> wrote: > On Mon, Jul 11, 2016 at 12:05 PM, Ketan Maheshwari < > [email protected]> wrote: > >> Hello PETSC-ers, >> >> I am a research faculty at Univ of Pittsburgh trying to use PETSC/SLEPC >> to >> obtain the diagonalization of a large matrix using Lanczos or Davidson >> method. >> >> The matrix is a 3 dimensional dense matrix with a total of 216000 >> elements. >> >> After looking into some of the examples in PETSC as well SLEPC >> implementations >> it seems like most of the implementations are with 2 dimensional matrices. >> > > You will have to explain what you mean by a "3D matrix". A matrix, by > definition, has only > rows and columns. You may mean a matrix generated from a 3D problem. That > should pose > no extra difficulty. You may mean a 3-index tensor, in which case > diagonalization is not a clear > concept. > > Thanks, > > Matt > > >> So, I was wondering if it is possible to express a 3 dimensional matrix >> object >> compatible to PETSC so that the SLEPC API could be used to obtain >> diagonalization. >> >> Any suggestions or pointers to documentation or examples would be of great >> help. >> >> Best, >> -- >> Ketan >> >> > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > -- Ketan
