On Sun, 15 Mar 2015, Andy Wickert wrote:
EXAMPLE 1:
I want to present a time series of stream gage data. I would like a data
table to have:
time water_discharge_m3_s sediment_discharge_m3_s
And to have an entire time series of values for a given grass vector
category (i.e. vector point, in this case).
Andy,
This is a typical database table. Each row needs a unique ID. What I do
for all my environmental databases would be something like this:
CREATE TABLE Discharges (
site VARCHAR(30),
sampdate DATE, -- or use TIMESTAMP to have date and time in a single
samptime TIME, -- field.
h20disch REAL,
seddisc REAL,
PRIMARY KEY (site, sampdate, samptime)
)
Then assign your points to the site column.
EXAMPLE 2:
I have a series of data on sediment composition at a river site. For each
point, I want to have a 2D data table with multiple values for:
grain_size lithology
This would have a similar table structure. Columns (attributes) would
include sediment sample ID (the table's primary key that refers to a table
of sediment samples by location, date, and time), grain size, and
lithography.
From a statistical analytic point of view I would look at each sample as a
composition and apply models suitable for compositional data analysie (CoDA)
to them. CoDA was developed by geochemists and is appropriate for your data.
HTH,
Rich
--
Richard B. Shepard, Ph.D.
Applied Ecosystem Services, Inc. | Troutdale, OR 97060 USA
www.appl-ecosys.com Voice: 503-667-4517 Fax: 503-667-8863
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