ublas | Boost.uBlas - Boost | SDK library

by boostorg C++ Version: Current License: No License

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kandi X-RAY | ublas Summary

ublas is a C++ library typically used in Utilities, SDK applications. ublas has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

Boost Linear and Multilinear Algebra Library.

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Quality

Security

License

Reuse

Support

ublas has a low active ecosystem.

It has 87 star(s) with 142 fork(s). There are 13 watchers for this library.

It had no major release in the last 6 months.

There are 23 open issues and 17 have been closed. On average issues are closed in 134 days. There are 22 open pull requests and 0 closed requests.

It has a neutral sentiment in the developer community.

The latest version of ublas is current.

Quality

ublas has 0 bugs and 0 code smells.

Security

ublas has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

ublas code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

ublas does not have a standard license declared.

Check the repository for any license declaration and review the terms closely.

Without a license, all rights are reserved, and you cannot use the library in your applications.

Reuse

ublas releases are not available. You will need to build from source code and install.

Installation instructions are not available. Examples and code snippets are available.

It has 71 lines of code, 3 functions and 3 files.

It has medium code complexity. Code complexity directly impacts maintainability of the code.

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ublas Key Features

No Key Features are available at this moment for ublas.

ublas Examples and Code Snippets

No Code Snippets are available at this moment for ublas.

Community Discussions

Trending Discussions on ublas

for loop not executing on zero parameters

Inherit from boost::matrix

returning derivatives with boost odeint

Converting from boost::ublas to Eigen gives different results

How can BLAS library be directly used with boost multiarrays?

QUESTION

for loop not executing on zero parameters

Asked 2022-Mar-22 at 07:29

I am a self-taught python & C programmer and Iam now trying to learn C++

As a small exercise, I tried to port a function I had created in a Python minigame of mine, that generates a random matrix, then averages it, to create a map with terrain elevation.

I tried implementing it in C++ using a trick with size_t and the maximum size of an array, which I have already used successfully in C before.

However, the for-loop in my AverageSurroundings seems not to run when it is ran on row or column 0. This is confirmed by the output on stderr (I don't know how to put it in the question, sorry) and causes a division by zero error, which should not happen. I have done a small fix, but I can't find the origin of the problem

Here is a minimal snippet showing the problem.

...

ANSWER

Answered 2022-Mar-22 at 07:29

You make a call to AverageSurroundings with row==0 and/or col==0 (see your loop variables in Average).

But std::size_t is an UNSIGNED type... So when it's zero, minus 1, it underflows in AverageSurroundings's loops and returns 0xFFFF FFFF FFFF FFFF... Which is obviously greater than row+1 (or col+1). So the loop isn't executed not a single time.

Even without the underflow, you would still be outside your matrix, even with a proper "-1" as index...

Source https://stackoverflow.com/questions/71557313

QUESTION

Inherit from boost::matrix

Asked 2021-Dec-08 at 21:28

I would like to inherit from boost::matrix to enrich with some methods. I started with this :

...

ANSWER

Answered 2021-Dec-08 at 21:28

You don't need any of your additions to make this work:

Source https://stackoverflow.com/questions/70281683

QUESTION

returning derivatives with boost odeint

Asked 2021-Feb-22 at 10:54

I am using boost odeint to integrate 2n coupled equations. My basic question is quite general. How can I return not only the states x_i for each time step using the observer but also return the derivatives d(x_i)/dt? I know how to return the state or some function of the state at a given time, but I don't know how to return something which is a function of states at a given time and at times before.

To be more concrete, here is a simplified version of my code.

...

ANSWER

Answered 2021-Feb-22 at 10:54

A minimal example on what I mean with my comment

You would have to call the system function from inside the observer to get the derivatives values for the state. That is, pass the system object via the constructor of the observer, provide the return object and just call the function and evaluate the results.

This is done via the m_odefun and m_dxdt fields. The example uses the standard vanderPol oscillator which is a second-order DE giving a first-order system with 2-dimensional state vectors. (The observer does not need to be templated, this was just done to follow the odeint template practice.)

Source https://stackoverflow.com/questions/66277050

QUESTION

Converting from boost::ublas to Eigen gives different results

Asked 2021-Feb-01 at 15:15

I am currently porting an algorithm from boost::ublas to Eigen:

Code 1 with boost::ublas

...

ANSWER

Answered 2021-Feb-01 at 15:15

You didn't specify any inputs or what the discrepancy is you're finding.

This lead me to build simple testers, in which I find that an obvious source of "differences" is the inaccuracy of [binary] floating point representations.

You can easily confirm it with some test input: whose inverse is :

Live On Compuler Explorer

Source https://stackoverflow.com/questions/65991639

QUESTION

How can BLAS library be directly used with boost multiarrays?

Asked 2020-Aug-23 at 21:15

Given two matrices A and B, and C for the result of their multiplication.

...

ANSWER

Answered 2020-Aug-23 at 21:15

You can access the contiguous element storage.

The prototype is

void cblas_dgemm( CBLAS_LAYOUT layout, CBLAS_TRANSPOSE TransA, CBLAS_TRANSPOSE TransB, const int M, const int N, const int K, const double alpha, const double *A, const int lda, const double *B, const int ldb, const double beta, double *C, const int ldc )

So, let's fill it in:

Source https://stackoverflow.com/questions/63535943

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install ublas

You can download it from GitHub.

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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