Full document / COSOC-W-86-002 - the National Sea Grant Library

Table 1.~Data Dictionary for Selected Variables In the National
Estuaries Program Data Base.
SAS Variable Length
Name Type (Bytes)
DO Numerla 8
B0D5 Numeric a
CBLOHAC Numeric 8
CHLORAU Numeric 8
NB3 Numeric 8
SALIN" Numerlo 8
SECCHI Numerlo 8
DEPTH Numeric 8
STATION Character IS
SEGMENT Charaoter 5
SAS Estuarine Data Analysis
SAS Label
Dissolved Oxygen (mg/1)
5 Day Biological Oxygen Demand (mg/1)
Chlorophyll A Corrected (ug/1)
Chlorophyll A Uncorrected (ug/1)
Ammonia as U (mg/1)
Salinity (ppt)
Seoohl Depth (m)
Station Depth (m)
Sampling Station
Many statistical procedures for summarizing and analyzing estuarine
data are available In SAS (Figure 1). These can be divided into three
major groups - descriptive, model building, and Inferential. Several
of the descriptive procedures ore discussed below. The model building
procedures Include PROC REG (for regression analysis), PROC CORR (for
correlation analysis), and PROC DISCRIH (for discriminant analysis).
Inferential procedures are used to statistically test hypotheses about
some estuarine process. An example is PROC OLH, which is used for
linear model analyses. These procedures typloally require one or more
assumptions about the distribution of the data, and sometimes about the
sampling/experimental design. They are not always appropriate for the
analysis of historical data, but ore very powerful for analyzing data
from a designed experiment or sampling program.
Examples of SAS Deaorlptlve Statistical Procedures
PROC FREQ is used to desoribe both character and numeric data. Its
primary purpose is to caloulate observed frequency counts for one or
more variables. The frequency aounts are presented in a frequency
table, which can be one-way or multi-way (for orosstabulatlons of two
or more variables). This procedure oan also compute various
statistical tests of association or independence, auoh as the usual
Chi-Square Test.
PROC UNIVARIATE computes various statistics describing the
distribution of one or more numerlo variables. Included are measures
of central tendency such as the mean and median, and estimates of
variability suoh as the standared deviation and range. The procedure
also oomputes a number of usoful quantlles, including the sample
quartilea and various percentiles. These and other statistics are
presented In a concise table.
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