XCI32.DLL

This DLL contains routines to estimate the confidence intervals of proportions. I, frankly, do not 
know which are better than others, only that they give very similar results for small numbers. The 
code was derived from the Turbo Pascal DOS program by Ray Simons XCI.EXE and, as far as I can tell, 
gives identical results.

The DLL was created in around 2002 to add this functionality to Windows spreadsheet software, namely
Excel I no longer use Microsoft Office, so haven't tested these with recent versions of Excel but
now use OpenOffice. 

Included in the XCI21.ZIP:-

XCI32.DLL	DLL containing run-time routines
XCI.PAS   	Header file for Pascal programs
XCI32.DPR )     Source code for XCI32.DLL ( Deplhi 2 )
XCI32.BAS   	Sample header file for Visual Basic applications ( e.g. Excel, OpenOffice )
WinXCI.EXE	Stand-alone 32-bit Windows program, uses the DLL.
XCI32.TXT       This file.
 
The purpose of these routines is to add confidence interval estimations of proportions
following the methods of Clopper-Pearson, Fleiss, Wilson & Fisher Mid-Point.

I have not tested these on other software.

See XCI32.BAS for a sample header file for Microsoft applications. See XCI.PAS for headers for
use with Delphi. See your application help to insert the macro. Each function returns the upper
or lower interval respectively.


USAGE

Firstly copy the file XCI32.DLL to a suitable folder in your system. I would recommend the folder 
containing the executable using the file. Alternatively copy to your Windows directory. Should 
you have another file of the same name, I suggest you rename this one and adjust your header 
files accordingly. You CAN load the DLL virually anywhere, bur you will need to provide a full path
as well as the filename.

Each function has the same call, in Dephi e.g:-


function WilsonUpper( success, total: integer; prob : double ) : double;
would be called as, e.g

CIU95 := WilsonUpper( success, total, 0.95 );

In BASIC
Cui95 = WilsonUpper( success; total; 0.95 )

Note the semicolons - required in OpenOffice, though probably commas in others!


will return the upper limit of the ratio as a double, given the number of successes, total number 
of trails and the probability for your confidence interval. The function Wilsonlower will return 
the lower boundary.

If using VisualBasic or applications that use it ( e.g. Excel ), use the header file as supplied 
- it may be modified if needed.

Finally,  OpenOffice is VERY picky over case, if in doubt use uppercase ( Capitals ) for the calls.
 
Richard Muirhead.
rmuirhead@compuserve.com




