Starting with ArcBME

1
Starting with ArcBME
2
Agenda

• Temporal GIS (TGIS) Analysis Overview
• Interaction with ArcGIS
• Software structure
• Step by step instruction

3
Temporal GIS Analysis Overview
4
Temporal GIS Analysis Overview

• ArcBME consists of six screens
• Data Field screen
• Data Distribution screen
• Exploratory Data Analysis screen
• Mean Trend Analysis screen
• Space/Time Covariance Analysis screen
• BME estimation screen

5
Data Input Screen

• Column Matching
• Input units and name of compound

6
Data Distribution Screen

• Basic statistics
• Histogram (Raw data and log-transformed data)

7
Exploratory Data Analysis Screen

• Time series at monitoring station
• Spatial distribution
• Data aggregation

8
Mean Trend Analysis Screen

• Display temporal mean trend
• Display spatial mean trend (Raw Smooth)
• Model Parameter (Exponential Smoothing)

9
Covariance Analysis Screen

• Display spatial temporal covariance
• Plot covariance models

10
BME Estimation Screen

• Time series of BME mean estimation
• Map of BME mean estimation
• Map of BME error variance

11
Interaction with ArcGIS
12
Interaction with ArcGIS

• ArcBME creates following ArcGIS files
• Point layer file (BME mean estimation, BME error
  variance)
• BME mean estimation raster file
• BME error variance raster file

13
Interaction with ArcGIS
14
Software structure
15
Software Structure
ArcGIS Geoprocessing Tools
GTK
matplotlib
pygtk
win32com
ArcBME
bmelibpy
Python
Numeric
SciPy
Numarray
Matlab Compiler
Matlab .exe file
MCR
16
Features of Python

• Cross-platform language
• Very simple syntax rules
• Open source software Free!
• Support Object Oriented Programming
• Scripting language widely used in ArcGIS
• A number of additional modules
• Math and science modules
• Graphical user interface modules

17
Sample Code
u 0 v 0 x 100 y 30 while x gt y u u
y x x y if x lt y2 v v
x x 0 else v v y 2
x x y 2 print u, v
while-statement block
if-statement block
From The Quick Python Book (Manning)
18
Step by step instruction
19
Before you start the TGIS analysis

• You need the data file!
• Your data set MUST have
• X field, Y field (Spatial Location)
• Time Field (Temporal Location)
• Data Value
• Data Type (Optional)
• Data MUST be stored in GeoEAS format
• Tab separated file with header

20
GeoEAS format
Tetrachloroethene(micrograms per liter) in New
Jersey 7 LONGITUDE LATITUDE NUM
DAYS YEAR DATATYPE VAL1 VA
L2 -74.5278 40.5594 880 2001 0 0.01 0.01 -7
4.7781 40.2217 376 2000 0 0.01 0.01 -74.7781 40.
2217 410 2000 0 0.01 0.01
Number of Columns
File Description
Name of Columns
Tab-separated Data
21
Some Limitations

• Store data in vector form
• Grid data should be transformed
• Do not use comma ( , ) in column name
• Data value must be a numeric value
• Character string not acceptable
• Cannot perform 1-D or 3-D analysis

22
Download ArcBME

• From the class website, download TGISGUI_v1_0.zip
  into your afs space
• Unzip that file
• Python Development Modules(Modules)
• TGISGUI
• Put TGISGUI folder under your H drive
• If you want to use ArcBME on your laptop, you
  must also install the Python Development Modules
  (Need administrator right, see instruction in
  ENVR468 website)

23
Add Toolbox on ArcGIS

• Run ArcGIS, activate toolbox tool bar
• Right click and select Add Toolbox
• Select TGIS GUI Application toolbox from
  H\TGISGUI

24
Execute ArcBME

• Double click TGIS GUI Application
• Select Work Space and Data File

25
Work Space

• Work Space is a folder used to store the
  following ArcBME and ArcGIS files
• Parameter file (.ybp)
• Result file (.ybe)
• Estimation file (.yme, .yse)
• ArcGIS objects (.lyr, .dbf, raster)

26
Screen 1 Data Field

• Select data columns used for X Field, Y Field,
  Time Field, and Data Value
• Input Space Unit, Time Unit, Data Unit and Name
  of Data

Select Column Name
Input Units and Name of Data
27
Data Below Detection Limit

• Monitoring data often contains measurements below
  the level of detection
• How to deal with these measurements?
• Taking a half value of detection limit
• Construct softdata
• Eliminate data
• Taking a half value of detection limit is
  supported by ArcBME.

28
Datatype and Value 1 2 Field

• Datatype Field
• 0 Normal Data
• Use Valu1 field
• 1 Data Below Detection Limit
• Use (Value1 Value2)/2

(Sample) -75.0947 39.9014 1510 2003 0 2.30 2.30 -
74.5892 40.3133 445 2000 0 3.10 3.10 -74.5661
39.4397 1523 2003 1 0.00 0.10 -74.7656
39.6647 1504 2003 1 0.00 0.10
29
Screen 2 Data Distribution

• Basic statistics
• Mean, Standard deviation, Skewness, Kurtosis
• Histogram Raw data, Log-transformed data

30
Data Log-transformation

• If you want to use log-transformed data in the
  following analysis, check Use Log-transformed
  Data

31
Screen 3 Exploratory Data Analysis

• Time series at monitoring station
• Spatial map at specific time
• Data aggregation

32
Time series at monitoring station

• Input station ID
• Click Plot button

Input Station ID
Spatial coordinate of monitoring station
Click Plot button
Location of monitoring station
Zoom in/out
33
Spatial map at specific time

• Click Next Time to get the new map.

Plot new map
Zoom in/out
34
Data aggregation

• Check Aggregation Period box
• Enter aggregation period and click Aggregate
  Data

Check Box
Enter aggregation period
Click Button
Button will change
35
Quit ArcBME

• Click Quit button
• Dialog shows up, then click OK

36
Recovery from error

• You will get an error message
• Check error message and correct problem
• If you could not understand the error message,
  delete all files in Work Space and run ArcBME
  again
• Contact Info.
• BMElab MH0018
• Email akita_at_email.unc.edu