Applications Software Developments for 2000-2001 by BPX6rB

VIEWS: 1 PAGES: 4

									SAS Version 8                                       Program Editor designed to help reduce errors
                                                    in assembling SAS programs. The Enhanced
This article provides an in-depth summary of        Editor exercises a number of controls on
Version 8 of SAS which represents a major           program layout and performs a number of
new release of the SAS system together with         syntax checks on program statements. It also
brief details of the other software. Further        utilises colour to differentiate different
details of some of these products will appear in    components of a program such as data, code,
a future release of this (university) newsletter.   keywords and values.

Version 8 is a major release of the SAS             An additional window, not automatically
system, six years or so in the making, and          visible in the user interface but available on
contains many new facilities together with          request, is the VIEWTABLE window.
enhancements to existing facilities. This           Introduced as part of SAS/FSP in SAS Version
article describes just some of these                6, the VIEWTABLE window has now been
developments. A more complete description           made part of base SAS. The VIEWTABLE
of changes can be found by browsing the on-         window provides an easy way to enter data
line documentation provided with Version 8.         interactively. It also enables you to browse
                                                    and edit existing tables interactively.
Output Delivery System (ODS)
                                                    Statistical Analysis
The most significant development in SAS
Version 8 is the introduction of an Output          New Procedures in SAS/STAT
Delivery System (ODS). In previous versions
of SAS, the responsibility for output rested        SAS/STAT contains several new procedures:
with individual procedures. In Version 8, ODS
assumes the responsibility for the formatting of     KDE performs either univariate or bivariate
all output from SAS procedures. Using ODS,            kernel density estimation.
you can:
                                                     Four new procedures for linear modelling,
 Generate output data sets from procedures           non-linear modelling and smoothing are
 Customise your output using templates               provided:
 Store links to all components of your output
  in a new Results window                              LOESS implements a non-parametric
 Generate HTML files that format your                 method for estimating regression surfaces.
  results for viewing in a Web browser                 The LOESS procedure is suitable when
 Generate links in your output to allow drill-        there are outliers in the data and a robust
  down between tables and graphs in either             fitting method is necessary.
  direction when viewing output on the Web.            NLMIXED fits non-linear mixed models in
 Highlight cells in tables and reports using          which both fixed and random effects enter
  colour                                               nonlinearly.

User Interfaces                                        PLS fits models using a variety of linear
                                                       predictive methods, including partial least
Several new windows have been incorporated             squares.
in the Version 8 user interface. The Explorer
window provides a central point for managing           TPSPLINE uses penalized least squares to
basic tasks such as viewing and managing               fit a nonparametric regression model using
tables and libraries, and creating new libraries,      thin-plate smoothing splines.
library members and catalogue entries. The
Results window contains pointers to various          Three new procedures for spatial data
locations in the Output window. These                 analysis are available:
pointers serve as a contents page for your
output. Clicking on a particular pointer will          KRIEG2D performs ordinary kriging in
cause the associated output to be located in the       two dimensions.
Results Viewer window. The Enhanced
                                                       SIM2D produces a spatial simulation for a
Editor window is an alternative to the
                                                       Gaussian random field with a specified
   mean and covariance structure in two             The UNIVARIATE procedure now
   dimensions.                                       supports high resolution graphical displays.
                                                     You can generate histograms and
   VARIOGRAM computes sample or                      comparative histograms and optionally
   empirical measures of spatial continuity for      superimpose fitted probability density
   two-dimensional spatial data. These               curves for various distributions (beta,
   continuity measures are the regular semi-         exponential, gamma, log-normal, normal,
   variogram, a robust version of the semi-          and Weibull) and kernel density estimates.
   variogram and the covariance. These               You can generate quantile-quantile plots
   measures are written to an output data set,       (Q-Q plots) and probability plots to
   allowing plotting or parameter estimation         compare ordered variable values with
   for theoretical semi-variograms or                quantiles of a specified theoretical
   covariance models. You can then use the           distribution.
   KRIEG2D procedure for spatial prediction.
                                                   The Analyst Application
 Three new procedures – SURVEYMEANS,
  SURVEYREG and SURVEYSELECT –                     In addition to the developments in SAS/STAT,
  cater for sample survey design and               a new facility called ‘The Analyst Application’
  analysis.                                        has been introduced in Version 8. The Analyst
                                                   Application is a point-and-click interface to
   SURVEYMEANS produces estimates of               basic statistical analyses in the SAS System.
   survey population means and totals from         Areas covered include descriptive statistics,
   sample survey data. The procedure also          simple hypothesis tests, regression, analysis of
   produces variance estimates, confidence         variance, survival analysis as well as some
   limits, and other descriptive statistics. The   multivariate analyses. Some analyses not
   sample design can be a complex survey           currently available in SAS/STAT are also
   sample design with stratification,              provided, such as certain hypothesis tests and
   clustering, and unequal weighting.              basic sample size and power computations. In
                                                   addition, you can produce many types of
   SURVEYREG performs regression
                                                   graphs, including histograms, box-and-
   analysis for sample survey data. This
                                                   whisker plots, probability plots, contour plots,
   procedure can handle complex survey
                                                   and surface plots.
   sample designs, including designs with
   stratification, clustering, and unequal
                                                   The Analyst Application enables you to input
   weighting.
                                                   data in many ways, including opening data
   SURVEYSELECT provides methods for               from non-SAS sources such as Excel files,
   selecting probability-based random              inputting SAS data sets, or manually entering
   samples. The procedure can select a simple      the data yourself. Subsequent to entry, a
   random sample or a sample according to a        number of data manipulations may be
   complex multistage sample design that           performed such as editing, sub-setting, creating
   includes stratification, clustering, and        new variables and cases and creating variable
   unequal probabilities of selection.             transformations.

Changes and Enhancements in                        The analysis results and plots are presented in
SAS/STAT                                           separate windows and managed by a tree-list
                                                   structure called a project tree. The underlying
SAS/STAT contains numerous changes to              SAS code used to produce the results is
existing procedures. Two that stand out are:       available as a node in the project tree, and
                                                   results can also be displayed in HTML form
 The FREQ procedure now includes a                and viewed with a web browser. You can save
  TEST statement that provides asymptotic          projects and then recall them for further work.
  tests for selected measures of association
  and measures of agreement. It also               Graphics
  supports Monte Carlo estimation of exact p-
  values, instead of direct exact p-value          Changes fall into two categories–
  computation                                      enhancements specific to individual
                                                   procedures and a range of new methods for
creating graphics output for display on the        The GIFANIM driver enables you to use
World Wide Web.                                     SAS/GRAPH procedures to create GIF
                                                    animations for your Web pages.
Enhancements specific to SAS/GRAPH
procedures include:                                The JAVA device driver generates an
                                                    HTML file that defines graphics output as a
 HBAR3D, VBAR3D, and PIE3D                         Java applet.
  statements are available in PROC
  GCHART to generate 3-dimensional                 The ACTIVEX driver generates an HTML
  horizontal bar charts, vertical bar charts,       file that defines graphics output as ActiveX
  and pie charts using a variety of shapes.         controls.

 An HTML= statement available in the             Both the ACTIVEX and JAVA drivers can
  GANNO, GCHART, GMAP and GPLOT                   only be used with procedures GCHART,
  procedures uses HTML functionality to           GCONTOUR, GMAP, GPLOT, and G3D, and
  create graphics with "drill-down"               both must be used with the Output Delivery
  capability.                                     System (ODS). Both the ActiveX controls and
                                                  the Java applets are interactive when displayed
 An IMAGEMAP= statement, available in            in a browser. For example, they let you change
  the same procedures, generates a special        the chart type from a bar chart to a pie chart.
  data set that contains area and link            The ACTIVEX driver also allows you to
  information for creating custom HTML            zoom, slide and rotate graphs, although it is
  files with drill-down graphs                    restricted to working with Internet Explorer.

In addition to changes to specific procedures,    Applications Building
SAS/GRAPH software now provides several
methods for generating graphics output that       Substantial changes and enhancements have
can be displayed on the World Wide Web.           been made to the applications development
Most of these methods, described below,           module SAS/AF. These changes and
enable you to create graphs in which the user     enhancements include:
clicks on areas of the graph to "drill down" to
additional graphs or reports.                      A SAS Component Object Model
                                                    (SCOM) allowing the development of plug-
 The ODS HTML statement enables several
                                                    and-play components which adhere to
  SAS/GRAPH procedures to produce GIF
                                                    simple rules of communication enabling the
  graphics and a variety of HTML files for
                                                    sharing of information between
  creating Web pages with tables of contents,
                                                    components. The model supports attribute
  multiple frames, and drill-down
                                                    linking, model/view communication, event
  functionality.
                                                    handling and drag and drop.
 The GIF driver generates GIF graphics
  files from SAS/GRAPH procedures. These           New visual components (or controls) that
  files can be referenced in an HTML file and        provide improved rendering on all
  viewed with a Web browser.                         supported graphical operating systems.
                                                     They include a combo box, check box, push
 The HTML driver creates a series of                button, radio box, and others.
  graphs in GIF format and an HTML file
  that displays them.                              New non-visual components (or models)
 The WEBFRAME driver also creates                  that can be dropped onto a frame from the
  graphs in GIF format and HTML files, but          new Components window.
  it produces a Web page whose table of
  contents contains thumbnail depictions of        A new Build Window with improved user
  each graph, plus links to the full-sized          interface features. New features include:
  versions of the graphs.
                                                     - A common Properties window that is
                                                     shared by all components in a frame
   - A new Components window for creating
   both visual and non-visual objects on a
   frame

 An updated and improved Class Editor
  together with a corresponding Interface
  Editor and a Resource Editor.

 The Screen Control Language (SCL) has
   been renamed as the SAS Component
   Language and improved to offer further
   object-oriented development capabilities.
   Features of the revised language include dot
   notation and improved compile-time error
   checking.

Version 8 of SAS/AF is completely compatible
with applications and classes that were
developed using Versions 6 and 7 of SAS/AF
software.


Documentation
Complete reference documentation for SAS
Version 8 is now available on-line via a
product called SAS OnlineDoc. It can be
accessed from central servers or from a local
CD-ROM drive on a PC. In a Java-enabled
browser environment, SAS OnlineDoc
provides a search engine with full-text search
capabilities, as well as a detailed table of
contents and index. A plain HTML interface is
provided for use in browsers that are not Java-
enabled. SAS OnlineDoc is also available in
PDF format suitable for printing selected pages
of documentation. The SAS manuals continue
to be available in book form.

On-Line Tutorials
A revised set of tutorials is provided in SAS
OnlineTutor which take advantage of HTML
Java and the World Wide Web.

								
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