Top "Sparse-matrix" questions

A sparse matrix is a data structure in which not every entry is explicitly represented.

Best C++ Matrix Library for sparse unitary matrices

I am looking for a good (in the best case actively maintained) C++ matrix library. Thereby it should be templated, …

c++ matrix sparse-matrix lapack umfpack
slicing sparse (scipy) matrix

I would appreciate any help, to understand following behavior when slicing a lil_matrix (A) from the scipy.sparse package. …

python scipy slice sparse-matrix submatrix
kNN with big sparse matrices in Python

I have two large sparse matrices: In [3]: trainX Out[3]: <6034195x755258 sparse matrix of type '<type 'numpy.float64…

python scikit-learn sparse-matrix nearest-neighbor
What is a strided array?

There is also a counterpart which is called density array. What does this mean? I have done some search, but …

arrays data-structures sparse-matrix
Scipy sparse matrices - purpose and usage of different implementations

Scipy has many different types of sparse matrices available. What are the most important differences between these types, and what …

python matrix scipy sparse-matrix
Pandas sparse dataFrame to sparse matrix, without generating a dense matrix in memory

Is there a way to convert from a pandas.SparseDataFrame to scipy.sparse.csr_matrix, without generating a dense matrix …

python pandas scipy sparse-matrix
Apply PCA on very large sparse matrix

I am doing a text classification task with R, and I obtain a document-term matrix with size 22490 by 120,000 (only 4 million …

language-agnostic machine-learning sparse-matrix pca
Representing Sparse Data in PostgreSQL

What's the best way to represent a sparse data matrix in PostgreSQL? The two obvious methods I see are: Store …

sql postgresql relational-database sparse-matrix
How to parallelize this Python for loop when using Numba

I'm using the Anaconda distribution of Python, together with Numba, and I've written the following Python function that multiplies a …

python parallel-processing anaconda sparse-matrix numba
Efficiently create sparse pivot tables in pandas?

I'm working turning a list of records with two columns (A and B) into a matrix representation. I have been …

python pandas scipy scikit-learn sparse-matrix