srch

Create a sparse matrix with 10 nonzero values, but which has space allocated for 100 nonzero values. S = sparse(1:10,1:10,5,20,20,100); N = nnz(S) ... MATLAB ® stores sparse matrices in compressed sparse column format. For more information, see John R. Gilbert, Cleve Moler ...

Sparse matrices provide efficient storage of double or logical data that has a large percentage of zeros. While full (or dense) matrices store every single element in memory regardless of value, sparse matrices store only the nonzero elements and their row indices. For this reason, using sparse matrices can significantly reduce the amount of memory required for data storage.

Creating sparse matrices based on their diagonal elements is a common operation, so the function spdiags handles this task. Its syntax is. S = spdiags (B,d,m,n) To create an output matrix S of size m -by- n with elements on p diagonals: B is a matrix of size min (m,n) -by- p. The columns of B are the values to populate the diagonals of S.

example. S = sparse (i,j,v) generates a sparse matrix S from the triplets i , j, and v such that S (i (k),j (k)) = v (k). The max (i) -by- max (j) output matrix has space allotted for length (v) nonzero elements. If the inputs i, j, and v are vectors or matrices, they must have the same number of elements. Alternatively, the argument v and/or ...

Computation time on sparse matrices scales only with the number of operations on nonzero elements. Functions for creating and manipulating sparse matrices are listed in Sparse Matrices. To check if a function is supported for code generation, see the function reference page. Code generation does not support sparse matrix inputs for all functions.

I have to create a matlab matrix that is much bigger that my phisical memory, and i want to take advantage of the sparsity. This matrix is really really sparse [say N elements in an NxN matrix], and my ram is enought for this.

R = sprand( m , n , density ) creates a random m -by- n sparse matrix with approximately density*m*n ...

Creation and Working with Sparse Matrix in Matlab?

Sparse matrices provide efficient storage of double or logical data that has a large percentage of zeros. While full (or dense) matrices store every single ...

Creating sparse matrices based on their diagonal elements is a common operation, so the function spdiags handles this task. Its syntax is. S = spdiags (B,d,m,n) To create an output matrix S of size m -by- n with elements on p diagonals: B is a matrix of size min (m,n) -by- p. The columns of B are the values to populate the diagonals of S.

As it explains, the key to efficiently creating sparse matrices in MATLAB is to pre-compute an array of row, column, value triplets and then use a single ...

S = spalloc( m , n , nz ) creates an all-zero sparse matrix S of size m -by- n with room to ...

S = sparse(A) converts a full matrix to sparse form by squeezing out any zero elements. If S is already sparse, sparse(S) returns S . S = sparse(i,j,s ...

How do you primarily find content on Matlab Central (MLC)?. General web search. Specific web search for MLC content.

Create a 10,000-by-10,000 full storage identity matrix. A = eye (10000); whos A. Name Size Bytes Class Attributes A 10000x10000 800000000 double. This matrix uses 800-megabytes of memory. Convert the matrix to sparse storage. S = sparse (A); whos S. Name Size Bytes Class Attributes S 10000x10000 240008 double sparse.

Create a 10,000-by-10,000 full storage identity matrix. A = eye (10000); whos A. Name Size Bytes Class Attributes A 10000x10000 800000000 double. This matrix uses 800-megabytes of memory. Convert the matrix to sparse storage. S = sparse (A); whos S. Name Size Bytes Class Attributes S 10000x10000 240008 double sparse.

With S = spdiags(Bin,d,m,n), the m-by-n sparse matrix S is formed by taking the columns of Bin and placing them along the diagonals specified by d. Extended Capabilities. C/C++ Code Generation Generate C and C++ code using MATLAB® …

a full matrix into sparse form by squeezing out any zero elements. ... saves memory. ... an m -by- n all zero sparse matrix. ... a sparse matrix S from the triplets i ...

Creating sparse matrices based on their diagonal elements is a common operation, so the function spdiags handles this task. Its syntax is. S = spdiags (B,d,m,n) To create an output matrix S of size m -by- n with elements on p diagonals: B is a matrix of size min (m,n) -by- p. The columns of B are the values to populate the diagonals of S.

S = sparse( A ) converts a full codistributed matrix to sparse form by removing any zero elements. You can save memory by converting a matrix that contains many ...

Create a random 50-by-100 sparse matrix with approximately 0.2*50*100 = 1000 uniformly distributed nonzero entries. Specify the reciprocal condition number of the matrix to be 0.25 . R = sprand(50,100,0.2,0.25);

MATLAB® never creates sparse matrices automatically. Instead, you must determine if a matrix contains a large enough percentage ...

Sparse Matrices. Elementary sparse matrices, reordering algorithms, iterative methods, sparse linear algebra. Sparse matrices provide efficient storage of double or logical data that has a large percentage of zeros. While full (or dense ) matrices store every single element in memory regardless of value, sparse matrices store only the nonzero ...

S = sparse( A ) converts a full matrix into sparse form by squeezing out any zero elements. If a matrix contains many zeros, converting the matrix to sparse ...