CHƯƠNG 5
PHÂN TÍCH VÀ HIỂN THỊ
DỮ LIỆU
GIS for Everyone
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Truy vấn
• Selective search without modifying the original data (for
output)

Phân nhóm
Raw data Classified data

• Professional experiences
• Expert votes
• Empirical or analytical models
Chồng lớp
• adding layers, subtracting, multiplication, division, etc.
• Raster
Input data layer A
Input data layer B
Output data layer
Chồng lớp
• Arithmetic operation on two data layers using the vector
data model
Input
data layer A
Input


Nội suy không gian
Nội suy không gian
• Inverse Distance weighted
- IDW works by using a weight based on the distances
from an unknown value to known values

Arthur Lambor, Cornel University
© Paul Bolstad, GIS Fundamentals
Nội suy không gian
• Trend surface
- Polynomial regression to fit a least-square surface to the
input points

First-order (linear) trend surface Second-order (quadratic) trend surface
is Spatial Interpolation?
Nội suy không gian
• Fourier series
Single harmonic in
X
1
direction
Two harmonics in X
1

direction
Single harmonic in
both X
1
and X

• Applications – use of a seek function to model flow path
Phân tích mạng (dòng chảy)
• Application – find path through a sewer system from point
A to point B