We would like avoid allocating a huge array for the matrix and then having the user place on top of it.
In the new paradigm there could be options called on the resulting C of MatMatGetProduct() that would take effect before the C is fully formed to prevent the allocating and freeing for a huge array the same time as user array exists but with the current API we have for this release. > On Sep 23, 2019, at 9:59 AM, Zhang, Hong <hzh...@mcs.anl.gov> wrote: > > Yes, we should allow users to provide their own matrix array. > > We use MatDensePlaceArray() to plug an array into matrix C before > MatMatMult(). If we cannot do this, we will have to copy from the internal > array of the result C to our array. > > Would the following sequence work? > MatMatMultSymbolic() > MatDensePlaceArray() > MatMatMultNumeric() > This seems a reasonable API, but it is not obvious to users when and where > MatDensePlaceArray() should be called. > Currently, most users call MatMatMult(A,B, reuse,&C) instead of > MatMatMultSymbolic/Numeric. > > We plan to add > MatMatGetProduct(A,B,&C); > Then, > MatDensePlaceArray(C,array); > > Hong
