Re: [boost] [uBlas] [Tensor] multiprecision and FFT?

Am Mi., 6. Jan. 2021 um 23:19 Uhr schrieb Janek Kozicki via Boost < boost@lists.boost.org>:

Cem Bassoy via Boost said: (by the date of Wed, 6 Jan 2021 10:32:15 +0100)

...

Please consider to use and contribute to *Boost.uBlas*

Hi,

Does it work with boost::multiprecision types? In particular I am interested in types listed here:

http://yade-dem.org/doc/HighPrecisionReal.html

It does work with *boost::multiprecision*: Have a look @ https://godbolt.org/z/cMKc9T

Does it support FFT ?

You can get the pointer (like for vector) to the underlying contiguous memory (you do not own the memory): using format_t = boost::numeric::ublas::column_major; using tensor_t = boost::numeric::ublas::tensor; auto A = tensor_t(shape{3,4,2},2);auto ap = A.data(); You can also use the standard c++ library for convenience: std::for_each(A.begin(), A.end(), [](auto& a){ ++a; }); If you do not want to use the Einstein-notation, you can as well use either the prod function: // C3(i,l1,l2) = A(i,j,k)*T1(l1,j)*T2(l2,k); q = 3u; tensor_t C3 = prod(prod(A,matrix_t(m+1,n[q-2],1),q-1),matrix_t(m+2,n[q-1],1),q); "prod" uses internally a C-like interface which will not allocate memory at all. ttm(m, p, c.data(), c.extents().data(), c.strides().data(), a.data(), a.extents().data(), a.strides().data(), bb, nb.data(), wb.data()); Cheers, Cem

In particular I am interested in replacing my very crude NDimTable class with your code:

https://gitlab.com/cosurgi/trunk/-/blob/addQuantumMechanics_FixEnum_FixRebas...

I am about to start refactoring this part of the code, when I noticed your post.

best regards Janek

-- Janek Kozicki, PhD. DSc. Arch. Assoc. Prof. Gdańsk University of Technology Faculty of Applied Physics and Mathematics Department of Theoretical Physics and Quantum Information -- http://yade-dem.org/ http://pg.edu.pl/jkozicki (click English flag on top right)

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