NAG's Statistical Add-Ins for Excel - Frequently Asked Questions

Questions


Answers

  1. What versions of Excel do the Add-Ins support? [Top]

    The Add-Ins were formed under Excel 7.0 using Windows 95. They have been tested and shown to work under Excel Version 7.0 (Office 97), Excel 97 or Excel 2000 (Office 2000), Excel 2002, Excel 2003 and using Windows NT, Windows 98, Windows 2000 and Windows XP.

    They will not work under Excel 5.0 operating under Windows 95 or Windows NT. If you are interested in a version for this environment, please let us know by sending an email to feedback@nag.co.uk. Should there be sufficient demand then we would consider doing a specific implementation.
  2. The Add-Ins will not load. [Top]

    This is usually indicative of a faulty installation. Re-install the Add-Ins from the supplied media. Note that it is not sufficient to copy materials from one machine to another.
  3. We get error messages when we load the Add-Ins. [Top]

    On some systems error messages appear when the Add-Ins are loaded. Try NOT explicitly loading the NAG Add-In utilities, despite the message. In theory it should not have been necessary to explicitly load these since they are 'referenced' when each of the Add-Ins are formed. In practice, however, we found that several machine-operating-system and Excel-version combinations seemed to require explicit loading. At least one site has experienced a problem when explicitly loading the utilities Add-In, which they cured by simply relying on the referencing mechanism.
  4. The 'Nag' menu doesn't appear when I load the NAG Add-Ins. [Top]

    Make sure that all of the NAG Books, including NAGExtract, are not loaded. Now load the 'NAG Add-In Utilities'. From the 'User Defined' category in the function wizard, choose 'ChangeKey'. Call it with KeyName set to 'About' and NewValue set to 0. Repeat the process with KeyName set to 'Help' and NewValue set to 0.
  5. We get 'Trial' message boxes appearing when we load the NAG Add-Ins. [Top]

    This message appears because the software you have loaded is a trial version designed to work for a limited period only. If you would like to continue using the NAG Statistical Add-Ins for Excel you can order a licensed copy from here.
  6. The first release placed the Add-Ins in a NAG Category; where are they now? [Top]

    We have not discovered a 'clean' way of producing additional categories within Excel. We created a category by making a dummy Excel 4 macro. This opens up the possibility of creating a new category and we exploited this to create the 'NAG Books' category. The scheme worked most of the time, but on some systems it seemed to fail. Because of this we have reverted to placing the Add-Ins in the 'Statistical' category which already exists.
  7. The 'Nag' menu doesn't disappear when I unload the NAG Add-Ins. [Top]

    Make sure that all of the NAG Books, including NAGExtract, are not loaded. Now load the 'NAG Add-In Utilities'. From the 'User Defined' category in the function wizard, choose 'ChangeKey'. Call it with KeyName set to 'About' and NewValue set to 0. Repeat the process with KeyName set to 'Help' and NewValue set to 0.
  8. We get Microsoft Help when we want NAG Help. [Top]

    NAG help may be obtained from the 'Nag' menu within Excel by accessing NAGHelp.
  9. We get error messages whenever we open a second workbook. [Top]

    Set the properties of the NAG_Library.xla to read only. To do this, find NAG_Library.xla using Windows Explorer and right click on the file. Choose the 'Properties' option and then the 'general' tab. Check the Read-only box.
  10. We only obtain a <list of n> heading not a set of numbers. [Top]

    If you are using a NAG function that you are expecting to return several values then the call to this function must be entered as an Excel ARRAY FUNCTION. In practice this means that the destination cells must be pre-selected and that once the formula has been formed in the formula bar CONTROL-SHIFT-ENTER must be pressed to enter the formula. You will note that pressing this combination of keys causes the formula to have curly brackets around it in the formula bar. You will NOT get the same effect by explicitly typing these brackets.
  11. Are there any limitations on the size of data sets we can use? [Top]

    Most of the NAG Statistical Add-Ins for Excel are implemented as array functions. This makes it possible for results to be automatically updated on a worksheet when any of the data items change. However there is a Microsoft limit, in excess of 5000, on the number of elements that may be exported from an array function. It follows therefore that, for those routines where the amount of data reflects the amount of output, there will be a practical limit on the volume of data that can be handled correctly. Otherwise, as far as we are aware, there is no direct restriction on the size of the data sets that may be entered from Excel.
  12. Have you any examples of use? [Top]

    Please see the workbooks Book0E.xls, Book1E.xls, Book2E.xls, Book3E.xls or Book4E.xls as appropriate. These are supplied with the product.
  13. The 'Comments' on the examples worksheets seem truncated using Excel 97. [Top]

    Select the cell containing the comment. From the 'Insert' menu select 'Comment'. Resizing handles now appear on the comment box and these may be used to extend the box appropriately.
  14. We get a 'Catastrophic failure' message when we use the NAG Add-Ins. [Top]

    This may be because your trial license has expired. If this is the case, or if you have a licensed copy and are still receiving this error message, please contact your local NAG Response Center with the details of your problem.
  15. Can I obtain more copies of the manual? [Top]

    Extra copies can be printed from the Adobe Acrobat file on the CD, or via the Windows Help system. The User Manual is also available for download. [pdf]
  16. Will NAG be producing any more Add-Ins? [Top]

    The Add-Ins have been well-received and now cover two distinct areas: 'Modelling and Multivariate Methods' and 'Nonparametric Methods'. We are keen to learn of user requirements in this area, so please let us know these by sending an email to feedback@nag.co.uk.
  17. Will I be notified of any updates or additional materials? [Top]

    Please register with us to ensure that we can keep you up to date with future developments of this product line. If you have purchased the Add-Ins via a third party then it is especially important that you either complete the registration form in the Appendix (see registration), or register on-line. In addition to the benefits of being kept up to date with news about the NAG Statistical Add-Ins for Excel, this will also expedite our response to any questions you may subsequently have about the product and its usage.