In other words, I would have to implement this matrix header, using a 2nd order static_rank_tensor.
Unless the repo is already in a state where using matrix = static_rank_tensor<2,...> works. Is it ?
It is almost there. I need to refactor because there are some unclean parts.
@bassoy @amitsingh19975 could you kindly link me to the ongoing work (if there is any) on the new matrix class.
Type alias can be used but the error it generates isn't useful and it is very verbose for a normal user. The specialized class gives more control and a better error message. There is no new matrix class yet.
@amitsingh19975
Yes, there are two things that missing:
- Vector implementation
A Vector would just be a column or row of a matrix right? I.e. a matrix of {R, 1} or {1, C} dimensions, or should I update my implementation to create a new Vector class based off an array?
- Unit test in the test folder
Working on those right now. I'm new to the Boost Test Library, and I'll get back if I face any issues.
I have one questions for you why use the vector of vector?
I was comfortable with vectors. Upon deeper thought, a multidimentional-array based implementation would have worked better. I'll update my code to use the same!
@amitsingh19975
Yes, there are two things that missing:
- Vector implementation
A Vector would just be a column or row of a matrix right? I.e. a matrix of {R, 1} or {1, C} dimensions, or should I update my implementation to create a new Vector class based off an array?
That's true and there are a few reasons because of which we need a specialized version of vector:
- we are trying to replace the previous implementation
- it gives more control over the construction
- the normal user expects to find a vector class.
I have one questions for you why use the vector of vector?
I was comfortable with vectors. Upon deeper thought, a multidimentional-array based implementation would have worked better. I'll update my code to use the same!
why do you even need multidimensional arrays? Please look at the tensor_core, Eigen or any other high quilty library and see how it handles the matrix or tensor.
@amitsingh19975
why do you even need multidimensional arrays? Please look at the
tensor_core,Eigenor any other high quilty library and see how it handles the matrix or tensor.
Oh I understand, but what added benefits does A[i + C*j] give over something like A[i][j]?
I'll create a layout parameter too then, and go for a 1D array with A[i + x*j] where x = R or C according to the user wanting row major or column major.
@amitsingh19975
Yes, there are two things that missing:
- Vector implementation
A Vector would just be a column or row of a matrix right? I.e. a matrix of {R, 1} or {1, C} dimensions, or should I update my implementation to create a new Vector class based off an array?
That's true and there are a few reasons because of which we need a specialized version of vector:
- we are trying to replace the previous implementation
- it gives more control over the construction
- the normal user expects to find a vector class.
I have one questions for you why use the vector of vector?
I was comfortable with vectors. Upon deeper thought, a multidimentional-array based implementation would have worked better. I'll update my code to use the same!
why do you even need multidimensional arrays? Please look at the
tensor_core,Eigenor any other high quilty library and see how it handles the matrix or tensor.
Can there be two types for row vector and column vector? have the user customize the vector class via template arguments. It would give the user a much more explicit notation.
@amitsingh19975
why do you even need multidimensional arrays? Please look at the
tensor_core,Eigenor any other high quilty library and see how it handles the matrix or tensor.Oh I understand, but what added benefits does A[i + C*j] give over something like A[i][j]
- with the
A[i][j]you restricted with a particular layout and inC++you will be stuck with row-major. - if you need to extend for more dimensions, you will need to specify the dimension in advance, which is impossible for higher dimensions like a tensor.
- with the
A[i + C*j]you know they are contiguous in memory and pointed by a single pointer, not the pointer of pointers, you can pass them around without incurring performance loss. - and also compiler can help optimize the code.
@abakfja
Can there be two types for row vector and column vector? have the user customize the vector class via template arguments. It would give the user a much more explicit notation.
No need for two different types, we can use layout for example
auto row_vector = Vector<float, layout::row_major>(...);
auto col_vector = Vector<float, layout::col_major>(...);you could something like this.
@amitsingh19975
why do you even need multidimensional arrays? Please look at the
tensor_core,Eigenor any other high quilty library and see how it handles the matrix or tensor.Oh I understand, but what added benefits does A[i + C*j] give over something like A[i][j]
- with the
A[i][j]you restricted with a particular layout and inC++you will be stuck with row-major.- if you need to extend for more dimensions, you will need to specify the dimension in advance, which is impossible for higher dimensions like a tensor.
- with the
A[i + C*j]you know they are contiguous in memory and pointed by a single pointer, not the pointer of pointers, you can pass them around without incurring performance loss.- and also compiler can help optimize the code.
Sure, can we use the existing layouts(boost::numeric::ublas::column_major and boost::numeric::ublas::row_major) in the competency test? In the implementation we would be specializing tensor_core which already has layout defined.
tensor_core, but you can use the layouts defined by the boost because most of the operations are defined for the tensor, and there won't be much left to show your knowledge. If @bassoy beg to differ, then you can use it as he is the guy who has given the test.
For me, in a competency test, you shouldn't use
tensor_core, but you can use the layouts defined by the boost because most of the operations are defined for the tensor, and there won't be much left to show your knowledge. If @bassoy beg to differ, then you can use it as he is the guy who has given the test.
I will not use tensor_core in the competency test, by implementation I meant the actual project period.
Boost.uBLAS, is there a reason for it? Once you have forked the project and implemented the matrix, write the unit test using the boost unit test library in the test folder. After you are done with it, revert to me then I have a few questions for you.
tensor_core.
I implemented the given competency test. So, I request the mentors to review it. @bassoy @amitsingh19975
@shadymohamedamin, please go through the competency test again and follow the instructions. You need to create classes for matrix and vector, not hard-coding them.
thanks for considering uBLAS. you have the competency test description. prepare your solution and ping me when you are finished with your competency test. we will evaluate it and come back to you. Please read my comments posted on Jan 30 before you start your competency test.
Dear Mentor correct me if I wrong,
tensoris a mathematics topic and The code oftensoris written insidetensor_core.hppand many other header files .
Yes, isn't the matrix and vectors, though? I see matrix and vectors as the tensor's specialisation, and some will say the tensor is the extensions of vectors and the matrix into higher dimensions.
@amitsingh19975 @bassoy I had a few doubts while drafting the proposal for the GSoC Application.
- Since the second part of the implementation of
matrixandvectortypes, i.esubmatrixandsubvectoris dependent on the first project. Can I draft a proposal to work on the combination of these two projects into one. - If so what would the ideal order be like? For me it seems a preliminary implementation of
matrixandvectorbased as an extension oftensorwould not be that time consuming so beginning with that I can move towards working on thesubtensorand come back to implementsubmatrixandsubvector. Although doingsubtensorfirst and then doing the completematrixandvectoralong with their "sub" counterparts can also be a choice. - Another part I am not sure is the allocation of timeline. How much accurate should the timeline for the project be? in case of unexpected roadblocks etc.?
Thanks in Advance.
I am happy to announce that our GSoC students have successfully passed GSoC.
Both had an impactful contribution and showed great efforts to finalize their projects.
Congrats @exclowd and @shikharvashistha!
If you are interested in their projects, this is their wiki with project description.
@bassoy, I've created a new branch "fix/extents" to fix the existing problem with the ambiguous extents. My approach would be making the extents to be at least of 2nd order. Therefore, we can discern between static tensor and static rank tensor.
auto e0 = extents<1>{}; // [static rank extents] invalid because of 1st order static rank extents
auto e1 = extents<1,2>{}; // [static extents] valid because of 2st order static extents
auto e2 = extents<2>{}; // [static rank extents] valid because of 2st order static rank extents
auto e3 = extents<>{4}; // [dynamic extents] invalid because of 1st order dynamic extents
auto e4 = extents<>{4,4}; // [dynamic extents] valid because of 2st order dynamic extentsOrder(Static Extents|Dynamic Extents) > 1 and Order(Static Rank Extents) == 1. Therefore, there is no ambiguity.
@bassoy, there's one problem here, and I don't know which solution is better.
- should we put an invariant on static rank extents where the minimum order should be greater than one and lose the ability to alias the tensor into vector.
- should we make an exception for static rank extents and keep the aliasing ability.
There's one downside of alias on clang right now: they haven't implemented the type deduction for alias type. This makes it impossible to deduce the template types from the constructor.
I tried to use the example given in https://github.com/boostorg/ublas#simple-example and I'm getting bugs on my system. The keywords 'index','tenson_dynamics' and 'ones' are unrecognized. Is it a bug or anything else?
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@amitsingh19975 thanks for pointing this out. boostorg/ublas#150
