1. Cartographic Modeling
Eric Shook
Department of Geography
Kent State University

2. Cartographic Modeling
"Cartographic Modeling is a general methodology for the analysis and synthesis of geographical data" (Tomlin 1990)
Clearly and consistently decomposes spatial data processing into elementary components
Cartographic modeling is often expressed as a flowchart, which is called a procedure
Operation

3. Cartographic Modeling: Simple Example
Focal Mean
Contour Lines
Intermediate result
Many operations exist from buffers to calculating hill slopes to reclassifications

4. Cartographic Modeling: Simple Example
Focal Mean
Contour Lines
Intermediate result
Many operations exist from buffers to calculating hill slopes to reclassifications
We will not focus on the application of cartographic modeling.
Instead we will try to understand how cartographic modeling works.
What happens in those operation boxes? So we can create our own.

5. Local, Focal, Zonal, and Global Operations
Local Operation
Focal Operation
Zonal Operation
Global Operation

6. + = LocalSum 1 + 2 = 3 1 2 2 4 3 6 3 4 1 6 4 10 input1 input2 output
for i in range(0,2):
for j in range(0,2):
output[i][j]=input1[i][j]+input2[i][j]

7. * / % - = ... LocalAnything 1 2 2 4 3 4 1 6 input1 input2 output
Fill in the blank
for i in range(2):
for j in range(2):
output[i][j]=input1[i][j] ...

8. FocalMean 1 2 1 2 3 4 3 4 2
2.1
FocalMean = 1 2 1 2
2.6 3 3 4 3 4
Calculate Average
Value in 3x3 Window
for i in range(H):
for j in range(W):
output[i][j]=input1[i][j] + input1[i-1][j] input1[i+1][j] + input[i][j-1]
+ … … / 9

9. ZonalMean 1 2
2.5
2.5 3 4 3 4
2.5
2.5
2.5
2.5
ZonalMean = 2 1
2.5
2.5 3
2.5
Calculate Average
Value in Zone
for i in range(H):
for j in range(W):
z=getzoneatlocation(i,j)
output[i][j]= zonesum[z] / zonecount[z]
* Requires pre-calculating zonesum and zonecount for each zone (z)

10. GlobalMean
... .5 .5 .5 .5 .5 .5 .5 .5
GlobalMean = .5 .5 .5 .5 .5 .5 .5 .5
Calculate Average
Value Globally
for i in range(H):
for j in range(W):
output[i][j]= globalsum / globalcount
* Requires pre-calculating globalsum and globalcount

11. Cartographic Modeling Broken Down
Procedure is a sequence of Operations
Operation
Layer
Operation
Location
Function

12. Cartographic Modeling Broken Down
Procedure is a sequence of Operations
Operation
Layer
Operation
for i in
for j in
Location
Function
layer_name[i][j]
Processing code
for each location

13. Space Ordering Row Order* Row-Prime Order Morton Order Hilbert Order
Cantor Order
Spiral Order
* The standard "for i, for j" loop is row order