Rcplex (version 0.2-1)

simple_triplet_matrix: Create sparse matrix with triplet representation

Description

Create a sparse matrix, with entries stored by triplets (row,col,entry).

Usage

simple_triplet_matrix(i, j, v, nrow = max(i), ncol = max(j))

Arguments

i

Row indices of entries

j

Column indices of entries

v

Entries

nrow

Number of rows in matrix

ncol

Number of columns in matrix

Value

• Returns S3-style object of class simple_triplet_matrix
• i
  Row indices of entries
• j
  Column indices of entries
• v
  Entries
• nrow
  Number of rows in matrix
• ncol
  Number of columns in matrix

Details

For usage in Rcplex, entries must be given in column major order, i.e. component j must be in ascending order

Examples

## Define matrix
## 1 0 3
## 0 1 2
## 3 2 0
mat <- simple_triplet_matrix(
   i=c(1,3,2,3,1,3),
   j=c(1,1,2,2,3,3),
   v=c(1,3,1,2,3,2));
print(mat);

# coerce to matrix
as.matrix(mat);

# transpose
as.matrix(t(mat));

# indexing
mat[1,1];
mat[1,];