Scipy sparse matrix question
Hi, I have the following code in Python using Numpy: p = np.diag(1.0 / np.array(x) How can I transform it to get the sparse matrix p2 with the same values as p without creating p first? Thanks! ...
sparse
more efficient sparse matrix element accessor
Hi, I wrote a small sparse matrix class with the member: std::map<int,std::map<int,double> > sm; The method below is the function i use to access the elements of a matrix, if not possible through an iterator: double matrix::operator()(int r,int c) const { std::map<int,std::map<int,double> >::const_iterator i = sm.find(r); if(...
Implementation of extremely sparse arrays
I have an extremely sparse static array with 4 dimensions of 8192 each that I want to do lookups from (C#). Only 68796 of these 4.5 * 10^15 values are non-zero. What is the fastest way to do this, with speed and low memory usage being vital? Thanks ...
How to create a sparse file on NTFS?
I'm testing a sparse file. But my test code doesn't work well. HANDLE h = CreateFileW(L"D:\\sparse.test", GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE, 0, CREATE_ALWAYS, FILE_ATTRIBUTE_ARCHIVE|FILE_ATTRIBUTE_SPARSE_FILE, 0); DWORD d = GetFileAttributes(L"...
Sparse Files and Disk Quotas
Suppose, My D: volume capacity is 100GB. And I'm using it 80GB now. The remain is only 20G. Now, I try to make a sparse file. DWORD written; std::wstring s = L"D:\\sparse9.test"; HANDLE h = CreateFileW(s.c_str(), GENERIC_WRITE, FILE_SHARE_DELETE, 0, CREATE_NEW, 0, 0); if(!DeviceIoControl( h, FSC...
Sparse sorted numeric sequence class for .NET
Hello everyone. I'm in need of very specific class, I would really like to know if there is existing one, so I don't have to re-implement it. I have a set of items. Each item has a numeric value associated whit it - weight. Weight of each item is unique within set. Items must be sorted by weight. Weight can be modified for each item, but...