The World of Computer Software/World_Of_Computer_Software-02-385-Vol-1of3.iso/e/estat21.zip/EASIDOC.ZIP/ESCHAP01.DOC

Text File | 1992-07-23 | 20KB | 462 lines

     Chapter 1: BASIC INFORMATION

     Welcome to EASISTAT. This chapter contains information
     about the programs and other files which are distributed
     as part of the EASISTAT package.


     1:1. The EASISTAT programs

     EASISTAT is an inexpensive but functional statistics
     program which runs on IBM PC's and compatibles and which
     performs the following statistical procedures:

     Mean, mode, median, standard deviation, variance,
     standard error of mean, skewness, kurtosis, chi-squared
     test, Fisher's exact test, Wilcoxon's rank sum and signed
     rank sum, Kolmogorov-Smirnov, Kendall's rank correlation,
     paired and unpaired t tests, one way analysis of
     variance, Kruskal-Wallis analysis of variance by ranks,
     linear regression with Pearson's correlation coefficient,
     multiple linear regression, principal component analysis
     and general minimisation.

     Calculator and table look-up functions are also
     available. Complex arithmetic and logical expressions can
     be used for case selection or to transform variables, and
     these can be stored as macros. There is a spreadsheet-
     type data editor to enter or modify data, and data is
     kept in simple ASCII files to allow easy conversion to
     and from other formats. With 640k of RAM a total of about
     seventy thousand data points can be accommodated in
     practically any number of rows or columns. The program is
     controlled by commands and an important feature is that
     it can be run either interactively from the keyboard or
     in batch mode from command files.

     EASISTAT was written in C and C++, and the program and
     data are both held entirely in memory so that there is no
     loss of speed due to buffering to disk or overlay-
     loading. Data analysis is thus very fast. If you have a
     maths coprocessor then EASISTAT will make use of it to
     perform calculations even more quickly. The minimum
     requirement to run EASISTAT is an IBM PC compatible with
     300k of free memory and one floppy disk drive and DOS 2.0
     or higher.

     EASIGRAF is a graphing program which is distributed with
     EASISTAT, although it can also be used on its own to
     graph data produced by other programs or entered by hand.

     The following graph types can be produced:

     Bar, scatter, and line plots, absolute, cumulative and
     percentage distributions of a variable in one or two
     groups, two-way frequency distribution, vertical scatter
     plots in groups, X-Y plots, multiple X-Y-Z plots.

     EASIGRAF runs on an IBM PC compatible and works with CGA,
     EGA, VGA, and Hercules displays as well as several rarer
     display types.


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     As well as EASISTAT and EASIGRAF there is a simple text
     editor supplied called EDIT, a pop-up calculator called
     EASIMATH and a small utility for printing out graphs
     called PRMSP.


     1:2. Limitation of liability

     It is possible that this documentation or the programs
     supplied contain errors which mean that the programs do
     not behave in the way described. We have attempted to the
     best of our ability to eliminate such errors, but it is
     possible that some do exist. If you discover such an
     error then please inform us of it (see the section on
     "Bugs" below). If the software or manual contains
     significant errors rendering the programs unusable then
     our liability is limited to replacing defective material
     that we have supplied or refunding the purchase price
     paid. No liability can be accepted for anybody who has
     not paid for the programs and become a registered user.
     In any event the liability of ARC Scientific with respect
     to problems associated with the use of these programs
     through such errors or through other circumstances shall
     not exceed the price of the programs as published by ARC
     Scientific or as paid by the user, whichever is the
     lower. Use of the software supplied constitutes an
     understanding and acceptance of such limitation of
     liability.


     1:3. The Shareware concept

     One way for the programmer to distribute useful programs
     to users is through ordinary retail outlets - shops and
     mail order companies. This demands high overheads for
     many middlemen and forces up the final price of the
     program to the user. In addition the user must pay for a
     program before he or she acquires it, usually having to
     judge its merits second-hand by means of a review or
     advertising copy. Programs acquired in this way are
     normally copyright and it is forbidden and illegal to
     copy them. Often they are in fact copied illegally,
     forcing up prices further, or else the distributor is
     obliged to apply some form of copy-protection to the
     program which reduces its convenience of use.

     The Shareware alternative is to allow individuals to copy
     a program freely and to encourage them to pass it on to
     their friends or colleagues for evaluation purposes. The
     program remains copyright but the holder of the copyright
     grants restricted permission to individuals in possession
     of the program to make copies of it. Potential users can
     evaluate the program first-hand and are only requested to
     pay for the program if they decide that they wish to
     continue to make use of it. Because of the low
     distribution costs the price for a Shareware program can
     be many times lower than for an equivalent program sold
     conventionally. The success of the Shareware concept
     depends on those people who do feel it is reasonable to
     pay for something which they find useful. In the case of
     the EASISTAT programs people who pay for the software
     will be added to the list of registered users and will

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     receive a fully indexed printed manual.

     The Shareware agreement

     You are assumed to understand and accept the following
     conditions as a basis for your possession and use of the
     EASISTAT programs and associated files. If you do not
     accept them then please erase the programs from your
     disk.

     EASISTAT is distributed as Shareware. That means that you
     are legally allowed to copy the programs and give copies
     to other people who you think might like them - in fact
     you are encouraged to do so. However please note the
     following points:

     1. The copyright of the programs remains with ARC
     Scientific limited.

     2. Although the programs may be freely copied and may be
     used for evaluation purposes, anybody who thereafter
     continues to use them must pay to become a registered
     user. Registered users will receive up-to-date versions
     of the programs and the full printed manual.

     3. You must not charge more than a nominal fee for the
     programs if you pass them on to someone else, nor may you
     distribute the disk as part of a promotional scheme
     without prior agreement with ARC Scientific.

     4. Please acknowledge the programs in any publications of
     work for which they are used.

     5. If you pass them on you must do so in unmodified form
     and the following files must all be passed on together:

     EASISTAT.EXE   EXAMPLE.DAT    DEMO           DEMO.BAT

     EASIGRAF.EXE   EXAMPLE.DAT    GDEMO          GRAFDEMO.BAT
     HDA.GRP        HISTO.GRP      ANOVA.GRP      REGRESS.GRP
     TRIGS.GRP      FRILLY.GRP     WAVE.GRP

     READ.ME        ORDER.PRN      INVOICE.PRN    EDIT.EXE
     EASIDOC1.EXE   EASIDOC2.EXE   UTILS.EXE

     In addition, the files should be passed on in such a way
     that it will be easy for the recipient to run the
     demonstration. What this means is that if the files are
     passed on using more than one floppy disk, then all the
     files in the first group above should be together on the
     same disk, and all the files in the second group should
     be together on the same disk. The first group of files
     are needed to run the EASISTAT demonstration, and the
     second group the EASIGRAF  demonstrations. As can be
     seen, this would necessitate making two copies of the
     EXAMPLE.DAT file.

     6. The printed manual is copyright and may not be
     reproduced or transmitted in whole or in part without the
     express permission of ARC Scientific Limited.



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     At time of writing, the price to register EASISTAT is
     forty pounds sterling, which is inclusive of delivery
     charges in the UK.

     Please address orders and enquiries to:

     ARC Scientific Limited
     257 Woodstock Road
     Oxford OX2 7AE
     England

     Tel. [phone]

     Order forms are provided in the file ORDER.PRN, which
     also contains details of shipping charges, etc. The file
     INVOICE.PRN contains an invoice form which can use to
     obtain a cheque from your purchasing department.

     If you give the programs and other files that go with
     them to someone else then please explain to them how to
     set the demonstrations running. If you give them a floppy
     disk with the EASISTAT files on we recommend that you
     write on the label:

     EASISTAT (c) ARC Scientific Ltd. 1989

     Enter -     A:
                 DEMO

     If there is not room for the EASIGRAF files on the same
     disk then on the disk containing the EASIGRAF files you
     should write:

     EASIGRAF Copyright (C) ARC Scientific Ltd. 1991

     Enter -     A:
                 GRAFDEMO


     1:4. User support

     Because of the low price of these programs we are able
     only to offer limited user support. If you have problems
     running them then please consult the manual carefully to
     see if that can help. If you still need advice then
     please write with a stamped addressed envelope to:

     EASISTAT User Support
     ARC Scientific
     257 Woodstock Road
     Oxford OX2 7AE

     We will attempt to answer your query as quickly as
     possible, though we cannot guarantee to be able to do so.
     Please give us as much detail as you can about the
     following information:

     Your DOS version number
     The version number of EASISTAT
     The type of computer and peripherals you have
     The names of any memory-resident programs
     The contents of your AUTOEXEC.BAT and CONFIG.SYS files

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     If you have problems using EASIGRAF then you should also
     let us know what type of monitor display you have. It
     might also be helpful if you enclosed a copy of any
     relevant data files and command files on a floppy disk.


     1:5. Specifications

     Nearly all the statistical functions implemented in
     EASISTAT are as described in Statistical Methods in
     Medical Research by P. Armitage and G. Berry (2nd
     edition, Blackwell Scientific Publications, 1987). The
     user is advised to consult this source for a detailed
     account of the theoretical basis of the tests and the
     circumstances under which they should be used. It is
     assumed that the user has at least a basic knowledge of
     statistics, and only brief descriptions of the tests will
     be given in this manual, which does not replace a
     statistics textbook.

     The significance values given are generally two-tailed,
     except for a few of the nonparametric tests for which it
     is expected that only small samples may be available and
     for which one-tailed significance values are output. If a
     test is one-tailed this is made clear when the p value is
     output. In practice this means that sometimes you may
     want to double the one-tailed probability value given
     (i.e. halve its significance) in order to produce a two-
     tailed significance value, depending for example on
     whether or not you had a prior hypothesis for the
     direction of the difference. Or you can just quote the
     result, say it is one-tailed and let people draw their
     own conclusions.

     EASISTAT and EASIGRAF run on a personal computer using
     MSDOS version 2.0 or later. Each requires about 300K of
     memory, but will use more if available (up to 640K). All
     data is held in memory for speed of calculations, so the
     amount of data which can be processed is limited by the
     size of the computer's memory. With 640K of memory
     EASISTAT will accommodate over 70,000 data points. The
     maximum length for a line read in from a data file is
     5,000 characters. The maximum number of data columns is
     about 1,300 and the number of rows must not exceed
     30,000. The maximum length for command lines is 240
     characters. Values are stored as single precision (four
     byte) floats and operations are carried out in double
     precision. Values stored in a data file are only stored
     on disk to the precision with which they are displayed.
     If a maths coprocessor chip is installed then EASISTAT
     will use it to increase the speed of calculations.

     EASISTAT will run in a text window of DESQview in
     background or foreground and will run under Microsoft
     Windows if the "Writes directly to screen option" is
     selected from the PIFEDIT menu. It can also made to run
     in a window of Microsoft Windows if the option to use the
     screen BIOS is selected.

     EASIGRAF will run under DESQview if the "Displays
     graphics information" option is specified and under
     Microsoft Windows if the "Writes directly to screen

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     option" is selected from the PIFEDIT menu. EASIGRAF can
     save files in Microsoft Paint format, allowing graphs to
     be read in and treated as pictures which can be edited by
     Microsoft Paint, or to be printed out with the supplied
     PRMSP program.


     1:6. Overview of the manual

     You should begin with the next chapter on "Getting
     started". You will probably wish to see the
     demonstrations if you have not done so already, and then
     you should carry out the installation procedure
     described. You should look through the chapter on
     "Command syntax", but you will probably wish to study
     this properly at a later date. Assuming that you do not
     already have data which you wish to analyse you will
     first have to enter some data using the EDIT command
     described in the chapter on "Data management commands".
     When you have entered your data you will wish to save it
     on disk, and this is done using the DATA SAVE command
     described in the chapter on "File management commands".
     Then you may try out any of the other commands described
     in the rest of the documentation. As you become more
     familiar with EASISTAT you should make an effort to
     familiarise yourself with the use of command files, and
     possibly with the more complicated arithmetic and logical
     operations available.

     EASISTAT is now supplied with a graph-drawing program,
     EASIGRAF, which can draw graphs from EASISTAT's data and
     graphically display some of the statistical tests
     implemented in EASISTAT. It can also be used for graphing
     data from other sources. The operation of EASIGRAF is
     explained in later chapters and users wishing to produce
     graphs should refer there. There are also a few utility
     programs which are provided, consisting of a simple text
     editor called EDIT, a pop-up calculator called EASIMATH,
     and a program to print graphs created by EASIGRAF called
     PRMSP. Each is described in its own chapter later in the
     manual.


     1:7. List of files supplied

     EASISTAT.EXE is the main statistics program.

     EASIGRAF.EXE is the graphing program which allows
     EASISTAT to display graphs. It can also be used on its
     own.

     EDIT.EXE is a simple text editor.

     UTILS.EXE is a self-extracting archive containing the
     utility programs EASIMATH.EXE and PRMSP.EXE. EASIMATH.EXE
     is a memory-resident calculator and PRMSP.EXE is a
     utility print out the Microsoft Paint files which
     EASIGRAF produces.

     EASIDOC1.EXE and EASIDOC2.EXE are two self-extracting
     archives containing (this) documentation for the
     programs.

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     EXAMPLE.DAT is an example data file and is used by DEMO
     and GDEMO. Although there is no need to, you may be
     interested to know what a few of the column titles refer
     to and this may help understand the demonstration and
     examples. The data were collected from a group of
     patients attending a hospital casualty department. AGE
     refers to one of five age groups. MSW refers to marital
     status, OCC to socio-economic class and EMP to employment
     status. ADD indicates address (roughly in terms of
     distance from central London). GHQ is a measure of
     illness filled in by the patient. It has a number of
     subscales, A, B, C and D which should sum to make TOT.
     HDA, HDD, CIS and SEV are measures of severity of illness
     arrived at using different procedures.

     DEMO.BAT is a DOS batch file which is run when you enter
     DEMO at the DOS prompt. It contains the line EASISTAT
     DEMO which runs EASISTAT with the command file DEMO as
     input.

     DEMO is an EASISTAT command file which demonstrates many
     of EASISTAT's features. It requires the file EXAMPLE.DAT.
     To use it from DOS the command EASISTAT DEMO is entered,
     or to use it from within EASISTAT the command INPUT DEMO
     is entered.

     GDEMO is another EASISTAT command file which shows how
     the program can work with EASIGRAF. It also requires the
     file EXAMPLE.DAT. To use it from DOS the command EASISTAT
     GDEMO is entered, or to use it from within EASISTAT the
     command INPUT GDEMO is entered.

     GRAFDEMO.BAT is a DOS batch file which demonstrates
     EASIGRAF with a number of example graph files which are
     supplied. These are all the files ending .GRP. Although
     they resemble the kind of graph files produced by
     EASISTAT, they have subsequently been modified slightly
     to provide a better idea of EASIGRAF's potential. To
     mention a few of them, HDA.GRP is the sort of file
     produced by the EASISTAT command called BASICS.
     REGRESS.GRP would be produced by the REGRESS command.
     ANOVA.GRP would be produced by the ANOVA command.
     HISTO.GRP would be produced by the CHISQ command. The
     others would mainly be produced by the COMPONENTS command
     and then modified afterwards.

     READ.ME contains some brief information about the
     programs and files supplied.

     ORDER.PRN is an order form.

     INVOICE.PRN is an invoice form. You may need to fill this
     in and present it to your purchasing department so that
     they will make out a cheque for your order.









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