Graphics Reference
In-Depth Information
panel and additional sorting criteria such as sorting from the highest increase over
no change to highest decrease in two selected years. he USU WNV micromap Web
site can be accessed at http://webcat.gis.usu.edu:
/index.html. Figure
.
shows
WNV death rates (let data panel) and death counts (right data panel) for the years
and
. he data are sorted by highest WNV death rate in
. A big dot
represents the year
, a small dot the year
. Red lines indicate an increase in
the rates/counts from
to
in a state, while green lines indicate a decrease
in the rates/counts from
to
. A strong geospatial pattern can be observed,
with highest WNV death rates in
in the Midwestern states. While death rates
(and counts) considerably increased from
to
for most of the states that
are currently visible in this scrollable micromap, the opposite holds for some of the
Central states such as Louisiana, Ohio, Mississippi, and Kentucky.
Constructing LM Plots
1.5
While the previous section describes major Web sites that provide access to their ge-
ographically referenced statistical data via LM plots, this section summarizes how
individual micromap plots can be constructed. his can be done using the statistical
sotware package S-Plus, by providing appropriate data and map files to an applica-
tion based onthesotware development kit (SDK)nViZn (Wilkinson etal.,
),or
by using recent Java code developed at the NCI. In particular, when high-resolution
LM plots in postscript (.ps) format are required and a screenshot from a Web site or
oneoftheJavaapplications isnotsu
cient,ausermostlikelywillhavetouseexisting
S-Plus code or will have to make changes to this existing code.
Micromaps via S-Plus
1.5.1
Individual LMplotscanbestbecreatedviaS-Plus.Sample S-Pluscode,data files,and
resulting plots can be obtained from Dan Carr's micromaps Web site at http://www.
galaxy.gmu.edu/~dcarr/micromaps. Included are files related to the early micromap
articles (Carr and Pierson,
; Carr et al.,
) as well as a frontend to S-Plus that
allowstheusertocreatetimeseriesmicromapplotsanddotplotmicromapplots.In
fact, the micromaps that are accessible at the USDA-NASS Web site were created by
USDA-NASS personnel using these tools.
S-Plus functions in the rlStateplot library, boundary files, data, and an example
S-Plus script file are also available at Dan Carr's micromaps Web site introduced
above. his library supports dotplots, dotplots with confidence bounds, barplots, ar-
row plots to show change, and boxplots based on county values. Boundary files are
available for US states and US counties. he datasets are cancer mortality rates from
the NCI.hescript file addresses howtoobtain moremortality rates over the Webas
well as examples showing different kinds of plots. More general S-Plus functions for
other regions and for times series that may need panel-specific scaling are available
from the second author.
