
Re: Large SparseArray in Mathematica 9 and the predictive interface
Posted:
Dec 31, 2012 7:45 PM


of course you should report this as a bug to Wolfram Support.... David
On Dec 30, 8:49 pm, jmm...@gmail.com wrote: > Hi there, > > I was generating a banded sparse array with the following code > in the new Mathematica 9.0: > > gmat[K_, l_, m_] := > Module[{bandU, bandL, bandD, res}, > > bandU = Table[l, {K  1}]; > bandL = Table[m, {K  1}]; > bandD = Table[l  m, {K}]; > bandD[[1]] = l; > bandD[[K]] = m; > > res = DiagonalMatrix[SparseArray[bandU], 1] > + DiagonalMatrix[SparseArray[bandD]] > + DiagonalMatrix[SparseArray[bandL], 1]; > > Return[res]; > ]; > > then I used the function with the following parameters (without semicolon: > > gmat[100, 0.8, 1] > > ...and everything was ok! a 100x100 sparse matrix was created and the > "predictive interface bar" appeared. > > Nevertheless, when I typed (without semicolon): > > gmat[10000, 0.8, 1] > > ...everything went not so good, a 10000x10000 sparse matrix was created > (what was ok), but the kernel went nuts with the memory use, some gigabytes > for a small sparsearray (You can try with greater parameters, but starting > with K=5000 things go weird) > > I think the problem has to do with the "predictive interface" that tries to > generate the normal form of the matrix, so it uses a lot of memory (and even > produces a kernel crash). > > Has anyone had the same problem with SparseArray? or have any > explanation to what actually happens? or it is just me? > > Many thanks in advance for any help or advice with this issue. > > Regards, > > Jose M. Martinez > Ph.D. Student > Department of Electronic Engineering > Universidad Tecnica Federico Santa Maria > Valparaiso, Chile

