NAG FL Interface
g11sbf (binary_​service)

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FL Specification Language:

1 Purpose

g11sbf is a service routine which may be used prior to calling g11saf to calculate the frequency distribution of a set of dichotomous score patterns.

2 Specification

Fortran Interface
Subroutine g11sbf ( ip, n, ns, x, ldx, irl, ifail)
Integer, Intent (In) :: ip, n, ldx
Integer, Intent (Inout) :: ifail
Integer, Intent (Out) :: ns, irl(n)
Logical, Intent (Inout) :: x(ldx,ip)
C Header Interface
#include <nag.h>
void  g11sbf_ (const Integer *ip, const Integer *n, Integer *ns, logical x[], const Integer *ldx, Integer irl[], Integer *ifail)
The routine may be called by the names g11sbf or nagf_contab_binary_service.

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. g11sbf calculates the number of different score patterns, s, and the frequency with which each occurs. This information can then be passed to g11saf.

4 References


5 Arguments

1: ip Integer Input
On entry: p, the number of dichotomous variables.
Constraint: ip3.
2: n Integer Input
On entry: n, the number of individuals in the sample.
Constraint: n7.
3: ns Integer Output
On exit: the number of different score patterns, s.
4: x(ldx,ip) Logical array Input/Output
On entry: x(i,j) must be set equal to .TRUE. if xij=1, and .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.
5: ldx Integer Input
On entry: the first dimension of the array x as declared in the (sub)program from which g11sbf is called.
Constraint: ldxn.
6: irl(n) Integer array Output
On exit: the frequency with which the lth row of x occurs, for l=1,2,,s.
7: ifail Integer Input/Output
On entry: ifail must be set to 0, −1 or 1 to set behaviour on detection of an error; these values have no effect when no error is detected.
A value of 0 causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of −1 means that an error message is printed while a value of 1 means that it is not.
If halting is not appropriate, the value −1 or 1 is recommended. If message printing is undesirable, then the value 1 is recommended. Otherwise, the value 0 is recommended. When the value -1 or 1 is used it is essential to test the value of ifail on exit.
On exit: ifail=0 unless the routine detects an error or a warning has been flagged (see Section 6).

6 Error Indicators and Warnings

If on entry ifail=0 or −1, explanatory error messages are output on the current error message unit (as defined by x04aaf).
Errors or warnings detected by the routine:
On entry, ip=value.
Constraint: ip3.
On entry, ldx=value and n=value.
Constraint: ldxn.
On entry, n=value.
Constraint: n7.
An unexpected error has been triggered by this routine. Please contact NAG.
See Section 7 in the Introduction to the NAG Library FL Interface for further information.
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library FL Interface for further information.
Dynamic memory allocation failed.
See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy


8 Parallelism and Performance

g11sbf is not threaded in any implementation.

9 Further Comments

The time taken by g11sbf 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 (g11sbfe.f90)

10.2 Program Data

Program Data (g11sbfe.d)

10.3 Program Results

Program Results (g11sbfe.r)