This routine is virtually identical to the Networks>Properties>Density routine, except that it provides more options for aggregating cells within a matrix block.

Name of file containing matrices to be blocked. Data type: Matrix.

Choices are

Whether diagonals are to be included in density calculations.

To partition the rows of the data matrix into blocks, specify a blocking vector by giving the dataset name, a dimension and an integer value. For example, to use the second row of a dataset called ATTRIB, enter "ATTRIB ROW 2". The program will then read the second row of ATTRIB and use that information to sort the rows of the matrix. All rows with identical values on the criterion vector (i.e. the second row of attrib) will be placed in the same block of the matrix. Densities will then be computed separately for each block. The block partitions can also be typed directly into the box by typing in a partition indicator vector. A partition indicator vector has the form (k1,k2,...,ki...) where ki assigns vertex i to group ki. So that (1 1 2 1 2) assigns vertices 1, 2 and 4 to block 1; and 3 and 5 to block 2.

To partition the columns of the data matrix into blocks, specify a blocking vector by giving the dataset name, a dimension and an integer value. For example, to use the second row of a dataset called ATTRIB, enter "ATTRIB ROW 2". The program will then read the second row of ATTRIB and use that information to sort the columns of the data matrix. All columns with identical values on the criterion vector (i.e. the second row of attrib) will be placed in the same block of the matrix. Densities will then be computed separately for each block.The block partitions can also be typed directly into the box by typing in a partition indicator vector. A partition indicator vector has the form (k1,k2,...,ki...) where ki assigns vertex i to group ki. So that (1 1 2 1 2) assigns vertices 1, 2 and 4 to block 1; and 3 and 5 to block 2.

Name of dataset that will contain the reduced block density matrix.

Name of dataset that will contain the original data with the rows and columns permuted to form the blocks.