nag_binary_factor_service (g11sbc) (PDF version)
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NAG Library Manual

NAG Library Function Document

nag_binary_factor_service (g11sbc)


    1  Purpose
    7  Accuracy

1  Purpose

nag_binary_factor_service (g11sbc) is a service function which may be used prior to calling nag_binary_factor (g11sac) to calculate the frequency distribution of a set of dichotomous score patterns.

2  Specification

#include <nag.h>
#include <nagg11.h>
void  nag_binary_factor_service (Nag_OrderType order, Integer p, Integer n, Integer *ns, Nag_Boolean x[], Integer pdx, Integer irl[], NagError *fail)

3  Description

When each of n individuals responds to each of p dichotomous variables the data assumes the form of the matrix X defined below
X= x11 x12 x1p x21 x22 x2p xn1 xn2 xnp = x̲1 x̲2 x̲n ,  
where the x take the value of 0 or 1 and x̲l=xl1,xl2,,xlp, for l=1,2,,n, denotes the score pattern of the lth individual. nag_binary_factor_service (g11sbc) calculates the number of different score patterns, s, and the frequency with which each occurs. This information can then be passed to nag_binary_factor (g11sac).

4  References


5  Arguments

1:     order Nag_OrderTypeInput
On entry: the order argument specifies the two-dimensional storage scheme being used, i.e., row-major ordering or column-major ordering. C language defined storage is specified by order=Nag_RowMajor. See Section in the Essential Introduction for a more detailed explanation of the use of this argument.
Constraint: order=Nag_RowMajor or Nag_ColMajor.
2:     p IntegerInput
On entry: p, the number of dichotomous variables.
Constraint: p3.
3:     n IntegerInput
On entry: n, the number of individuals in the sample.
Constraint: n7.
4:     ns Integer *Output
On exit: the number of different score patterns, s.
5:     x[dim] Nag_BooleanInput/Output
Note: the dimension, dim, of the array x must be at least
  • max1,pdx×p when order=Nag_ColMajor;
  • max1,n×pdx when order=Nag_RowMajor.
Where Xi,j appears in this document, it refers to the array element
  • x[j-1×pdx+i-1] when order=Nag_ColMajor;
  • x[i-1×pdx+j-1] when order=Nag_RowMajor.
On entry: Xi,j must be set equal to Nag_TRUE if xij=1, and Nag_FALSE if xij=0, for i=1,2,,n and j=1,2,,p.
On exit: the first s rows of x contain the s different score patterns.
6:     pdx IntegerInput
On entry: the stride separating row or column elements (depending on the value of order) in the array x.
  • if order=Nag_ColMajor, pdxn;
  • if order=Nag_RowMajor, pdxp.
7:     irl[n] IntegerOutput
On exit: the frequency with which the lth row of x occurs, for l=1,2,,s.
8:     fail NagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

6  Error Indicators and Warnings

Dynamic memory allocation failed.
See Section in the Essential Introduction for further information.
On entry, argument value had an illegal value.
On entry, n=value.
Constraint: n7.
On entry, p=value.
Constraint: p3.
On entry, pdx=value.
Constraint: pdx>0.
On entry, pdx=value and n=value.
Constraint: pdxn.
On entry, pdx=value and p=value.
Constraint: pdxp.
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
An unexpected error has been triggered by this function. Please contact NAG.
See Section 3.6.6 in the Essential Introduction for further information.
Your licence key may have expired or may not have been installed correctly.
See Section 3.6.5 in the Essential Introduction for further information.

7  Accuracy


8  Parallelism and Performance

Not applicable.

9  Further Comments

The time taken by nag_binary_factor_service (g11sbc) is small and increases with n.

10  Example

This example counts the frequencies of different score patterns in the following list:
Score Patterns

10.1  Program Text

Program Text (g11sbce.c)

10.2  Program Data

Program Data (g11sbce.d)

10.3  Program Results

Program Results (g11sbce.r)

nag_binary_factor_service (g11sbc) (PDF version)
g11 Chapter Contents
g11 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2015