Matlab and Geosptial data

1. HOW MATLAB HELPS
Zhang Xiaohu

2. WHY MATLAB
 Fast prototyping
 Toolbox
 IDE
 Warning:
 Fortran, LAPACK
 Efficiency -- Vectorization
 Alternative Option
 Octave http://www.gnu.org/software/octave/
 M_Map

3. DATA FORMATS SUPPORTED
 Vector Data
 ESRI Shapfile
 KML
 …
 Raster Data
 GeoTIFF
 Arc ASCII Grid
 …
 Relevant Data
 Image file formats
 NetCDF, HDF*, and Multband files (BIP,BIL,BSQ)
 …
 WMS

4. OUTLINE
 Matlab and Geospatial Data
 Vector Data Manipulation
 Raster Data Manipulation
 Distribution Figures
 1-D Distribution
 2-D Distribution

5. VECTOR DATA MANIPULATION
 Read
 Structures
 Display
 Write
 Point, Polyline, Polygon

6. READ VECTOR DATA
 S = shaperead(filename, Name,Value, ...)
Field Name Data Type Description Comments
Geometry String
One of the following shape types: 'Point',
'MultiPoint', 'Line', or 'Polygon'.
For a 'PolyLine', the value of
the Geometry field is
simply 'Line'.
BoundingBox 2-by-2 numerical array
Specifies the minimum and maximum
feature coordinate values in each
dimension in the following form: Omitted for shape type 'Point'.
X, Y, Lon, or Lat 1-by-N array of classdouble Coordinate vector.
Attribute String or scalar number Attribute name, type, and value.
Optional. There are usually
multiple attributes.

7. READ VECTOR DATA
 Example
Point Polyline Polygon
Geometry 'Polygon'
BoundingBox [2x2 double]
Lon [1x5785 double]
Lat [1x5785 double]
AREA 54.447
PERIMETER 68.489
BOU2_4M_ 2
BOU2_4M_ID 23
ADCODE93 230000
ADCODE99 230000
NAME '黑龙江省'
Geometry 'Point'
Lon 116.3809
Lat 39.9236
AREA 0
PERIMETER 0
RES1_4M_ 1
RES1_4M_ID 61
GBCODE 31010
NAME '北京'
ADCODE93 110100
ADCODE99 110100
ADCLASS 1
PINYIN 'Beijing'
Geometry 'Line'
BoundingBox [2x2 double]
Lon [1x11 double]
Lat [1x11 double]
FNODE_ 18
TNODE_ 18
LPOLY_ 6
RPOLY_ 4
LENGTH 0.075
HYD1_4M_ 1
HYD1_4M_ID 1359
GBCODE 23010
NAME '克鲁伦河'
LEVEL_RIVE 3
EVEL_LAKE 1

8. DISPLAY VECTOR DATA
 worldmap [construct map axes]
 mapshow [without projection]
 geoshow [with projection]
 scaleruler
 northarrow

9. WRITE VECTOR DATA
 Write Point data

10. WRITE VECTOR DATA
 Write Line data

11. WRITE VECTOR DATA
 Write Polygon data

12. READ RASTER DATA
 [A, R] = geotiffread(filename)
 [Z,R] = arcgridread(filename)

13. WRITE RASTER DATA
 geotiffwrite(filename,A,R)
 Image Processing Toolbox
 Computer Vision System Toolbox

14. OUTLINE
 Matlab and Geospatial Data
 Vector Data Manipulation
 Raster Data Manipulation
 Distribution Figures
 1-D Distribution
 2-D Distribution

15. 1-D DISTRIBUTION
hist(data)
rose(data)
ksdensity(data)

16. 2-D DISTRIBUTION
scatter(x,y)
meshgrid
contour(data)
hist3(data)
contour(data)

17. THANKS