Hi Regina, On Thursday, 2010-08-12 16:38:33 +0200, Regina Henschel wrote:
> The current implementation avoids to copy the matrices X or Y, > although that would ease and shorten the code. I thought there must > be a reason for that and tried to avoid it too. I hesitate to copy X > or Y, because they might have a huge number of lines. Indeed. > I will try only using new matrices for products like X'X as it is > done in the current implementation. That will result in a lot of > nearly identical multiplication methods, but I think, that is better > than copying the matrices. To avoid both, having overly complicated code and copying large matrices, we could introduce a const/non-const flag in ScMatrix, defaulted to const and set to non-const by GetNewMat(), but to const again when stored in ScFormulaResult. The usual case is that a matrix was constructed from a range reference by the interpreter and not as a const array or formula cell result. Then having a ScMatrix::CloneIfConst() method could just return the current matrix if non-const and would have to actually clone only in rare const cases. Just an idea.. Eike -- OOo Calc core developer. Number formatter stricken i18n transpositionizer. Signature key 0x87F8D412 : 2F58 5236 DB02 F335 8304 7D6C 65C9 F9B5 87F8 D412 OpenOffice.org Engineering at Oracle: http://blogs.sun.com/GullFOSS -- Please don't send mail to the old e...@sun.com account that I used for mailing lists, it phased out. Use eike.rat...@oracle.com instead. Thanks.
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