I have a collection that consists of binary sequences.
I want to generate a Data Matrix based on that collection. Are there any libraries in Clojure that facilitate Data Matrix generation?
Edit: Like this.
I don't know of any specific library but you could easily implement this in Quil?
Here is an example of the Game of Life in Quil that's very similar to what you are looking for.
Related
I am trying to rewrite a matlab code to cpp and I still blocked with this line :
[c, l]=wavedec(S,4,'Dmey');
Is there something like that in opencv ?
if someone have an idea about it try to share it with and thanks in advance.
Maybe if you would integrate your codes with Python, then PyWavelet might be an option.
I'm seeing the function that you're looking for is in there. That function is called Discrete Meyer (Dmey). Not sure what you're planning to do with that though, maybe you're processing some images or something, but Dmey is OK, not very widely used. You might want to just find some GitHub codes and integrate to whatever you're doing to see if it would work first, and based on those you can also change the details of your currently posted function (might find something more efficient).
1-D wavelet decomposition (wavedec)
In your code, c and l stand for coefficients and level. You're passing level four with a Dmey function. If you'd have one dimensional data, the following map is how your decomposition would look like, roughly I guess:
There are usually two types of decomposition models that are being used in Wavelets, one is called packet which is similar to a Full Binary Tree, from architecture standpoint:
The other one, which is the one you're most likely using, is less computationally expensive, because it does not decompose both branches of a tree, if you will. It'd just do the mathematical decomposition in one branch of the tree. Maybe, these images would shed some lights:
1 D
2 D
Notes:
If you have a working model in MatLab, you might want to see the C/C++ Code Generation in MatLab, will automatically convert MatLab codes to C++.
References:
Images are from Wikipedia or mathworks.com
Wiki
mathworks
Wavelet 2D
I am in an Intro to data structures class and we are currently going over sorting algorithms. Is there any way in C++ to use a graph to trace the exchanging and sorting of sorting algorithms? There is an image illustrating shell sort if you follow this link and scroll down a bit. I also linked it down below. (Essentially what I would like to achieve). Addison Wesley, Algorithms 4th edition: http://algs4.cs.princeton.edu/21elementary/.
They spoke about using built in functions in Java to create the graph and spoke about it as if it is rather trivial. I'm assuming if its basic in Java its basic in C++.
Question being, how would I implement a function that would correspond numerically to how big the bars are and output the graph pre-sort, mid-sort and post-sort?
Note: I have intermediate level C++ knowledge and no experience with graphics.
Consider using a graphing package such as gnuplot. You would have to use it to plot, say as bar graphs, the array values your program is trying to sort.
currently I'm dealing with implementing a CBIR-System for object recognition (object classification in detail) and now since I have some working feature-detectors and -descriptors I try to find the best way for handling these features for the task of content based image retrieval.
As far as I know there are two main trends for this task, the discrete- and the continuous-approach. Where discrete stands for methods like bag-of-visual words and codebooks for building up inverted indices to apply methods referring text-retrieval, and continuous stands for methods like Best Bin First search with k-d trees and nearest neighbor classification.
So one main difference between those both approaches is, one works with an extra representation for features like visual-words and the other one works with the n-D features calculated from the descriptor.
My question is now, is there any comparison between the two method for CBIR which could help me in finding the best approach for my task?
The full answer to this question would be quite complex and long.
but generally, a continuous method can give you more accurate results, but it's slower as you can effectively build a search index, and you need to work with large descriptors.
you should consider a combination that uses discrete features (visual words) for initial results, and afterwards filter the result set using continuous methods.
I just wanted to know if any one had any pointers for a library or libraries that support Markov modelling and graphical graph representation, as for a project i must simulate a transport model and be able to develop an interface for it too. I am relatively new to c++.
Have a look at Boost Graph as it will simplify all your graph work. I am unsure if there is a Markov Chain algiorithm (I am looking for one too) but it should be easy to write once you have the graph -- a concurrent monte carlo approach maybe?
Numerical Recipes has many algorithm and code in both C and C++.
The graphviz tools are all you need to draw graphs.
I am currently working on a C++-based library for large, sparse linear algebra problems (yes, I know many such libraries exist, but I'm rolling my own mostly to learn about iterative solvers, sparse storage containers, etc..).
I am to the point where I am using my solvers within other programming projects of mine, and would like to test the solvers against problems that are not my own. Primarily, I am looking to test against symmetric sparse systems that are positive definite. I have found several sources for such system matrices such as:
Matrix Market
UF Sparse Matrix Collection
That being said, I have not yet found any sources of good test matrices that include the entire system- system matrix and RHS. This would be great to have in order to check results. Any tips on where I can find such full systems, or alternatively, what I might do to generate a "good" RHS for the system matrices I can get online? I am currently just filling a matrix with random values, or all ones, but suspect that this is not necessarily the best way.
I would suggest using a right-hand-side vector obtained from a predefined 'goal' solution x:
b = A*x
Then you have a goal solution, x, and a resulting solution, x, from the solver.
This means you can compare the error (difference of the goal and resulting solutions) as well as the residuals (A*x - b).
Note that for careful evaluation of an iterative solver you'll also need to consider what to use for the initial x.
The online collections of matrices primarily contain the left-hand-side matrix, but some do include right-hand-sides and also some have solution vectors too.:
http://www.cise.ufl.edu/research/sparse/matrices/rhs.txt
By the way, for the UF sparse matrix collection I'd suggest this link instead:
http://www.cise.ufl.edu/research/sparse/matrices/
I haven't used it yet, I'm about to, but GiNAC seems like the best thing I've found for C++. It is the library used behind Maple for CAS, I don't know the performance it has for .
http://www.ginac.de/
it would do well to specify which kind of problems are you solving...
different problems will require different RHS to be of any use to check validity..... what i'll suggest is get some example code from some projects like DUNE Numerics (i'm working on this right now), FENICS, deal.ii which are already using the solvers to solve matrices... generally they'll have some functionality to output your matrix in some kind of file (DUNE Numerics has functionality to output matrices and RHS in a matlab-compliant files).
This you can then feed to your solvers..
and then again use their the libraries functionality to create output data
(like DUNE Numerics uses a VTK format)... That was, you'll get to analyse data using powerful tools.....
you may have to learn a little bit about compiling and using those libraries...
but it is not much... and i believe the functionality you'll get would be worth the time invested......
i guess even a single well-defined and reasonably complex problem should be good enough for testing your libraries.... well actually two
one for Ax=B problems and another for Ax=cBx (eigenvalue problems) ....