file

Specify generating matrices read from file

Specification

• Alias: None

• Arguments: STRING

Description

The generating matrices will be read from an external file. The file format is

1 2 4 8 16 ... # m_max entries
1 3 5 15 17 ...
... # number of rows = maximum number of dimensions

Generating matrices should be provided as a matrix of integers.

The number of rows in the matrix determines the maximum dimension of the digital net. The number of columns in the matrix determines the log2 of the maximum number of points. An integer on the \(j\)th row and \(m\)th column encodes the \(m\)th column of the \(j\)th generating matrix \(C_j\). Since the \(m\)th column of \(C_j\) is a collection of 0’s and 1’s, it can be represented as an integer with \(t\) bits, where \(t\) is the number of rows in the \(j\)th generating matrix \(C_j\). By default, the encoding assumes the integers are stored with least significant bit first (see integer_format), so that the first integer on the \(j\)th row is 1.

When this keyword is specified, the user must also specify the log2 of the maximum number of points in the lattice using the keyword m_max, and the bit depth (the number of bits in the integers that encode a column of the generating matrix, or the number of rows in the generating matrices) using the keyword t_max.

Examples

environment
  tabular_data
    tabular_data_file = 'samples.dat'
    freeform

method
  sampling
    samples 32
    sample_type
      low_discrepancy
        digital_net
          # assume C.txt contains
          # 1 2 4 8 16
          # 1 3 5 15 17
          generating_matrices file 'C.txt'
          m_max 5
          t_max 5
          no_scrambling
          no_digital_shift

variables
  uniform_uncertain = 2
    lower_bounds 0.0 0.0
    upper_bounds 1.0 1.0

interface
  analysis_drivers = 'genz'
  analysis_components = 'cp1'
  direct

responses
  response_functions = 1
  no_gradients
  no_hessians