Monthly Archives: May 2014

How to share you PC’s internet as a WIFI hotspot

New Desktop or Laptop computers usually come with two internet adapters, Ethernet and wireless.  If you only use the Ethernet port for your computer, then you can share you PC’s internet as a WIFI hotspot via the wireless adapter. The easiest way to use Virtual Router Plus. You can download it from the link below.  Just unzip the downloaded zip file, and double click the VirtualRouterPlus.exe to run. Click “Start Virtual Router Plus”, then you are good to go.


If Virtual Router Plus does not work, you can try mHotspot.


2013 Geography Graduate Program Rankings

2013 Geography Graduate Program Rankings.

2014 Rankings – Top 10 Graduate GIS Programs

2014 Rankings – Top 10 Graduate GIS Programs.

Two new online GIS courses availabe on


Two new GIS online courses available on Good resource for GIS beginners.

  •  Up and Running with ArcGIS

  •  Real-World GIS

Training Students to Extract Value from Big Data: A Workshop




 Room 100

Keck Center of the National Academies

500 5th St NW, Washington, DC 20001[1]

 A Workshop of the Committee on Applied and Theoretical Statistics

 Sponsored by the National Science Foundation

Program Committee:

 John Lafferty, University of Chicago (co-chair)

Raghu Ramakrishnan, Microsoft Corporation (co-chair)

Deepak Agarwal, LinkedIn

Corinna Cortes, Google

Jeff Dozier, University of California, Santa Barbara

Robert Kass, Carnegie Mellon University

Anna Gilbert, University of Michigan

Rafael Irizarri, Harvard University

Patrick Hanrahan, Stanford University

Prabhakar Raghavan, Google

Nathaniel Schenker, Centers for Disease Control and Prevention

Ion Stoica, University of California, Berkeley




Friday, April 11th

 Breakfast available in the meeting room beginning at 8:00 AM

 8:30-8:40  Opening Remarks

Suzanne Iacono

Deputy Assistant Director

Directorate for Computer and Information Science and Engineering

National Science Foundation

 8:40-10:00  The Need for Training: Experiences and Case Studies


Raghu Ramakrishnan, Microsoft Corporation

John Lafferty, University of Chicago


Rayid Ghani, University of Chicago

Guy Lebanon, Amazon Corporation

 10:00-10:15  Break

10:15-12:45  Principles for Working with Big Data

 Chair: Brian Caffo, Johns Hopkins University


Jeffery Ullman, Stanford University

Alexander Gray, Skytree Corporation

Duncan Temple Lang, University of California, Davis

Juliana Freire, New York University

 12:45-1:45  Lunch

1:45-4:15  Courses, Curricula, and Interdisciplinary Programs

 Chair: Jim Frew, University of California, Santa Barbara


Bill Howe, University of Washington

Peter Fox, Rensselear Polytechnic Institution

Joshua Bloom, University of California, Berkeley

 4:15-4:30  Break

4:30-5:00  Q&A/Discussion

 Saturday, April 12th

 Breakfast available in the meeting room beginning at 8:00 AM

 8:30-11:00  Shared Resources

 Chair: Deepak Agarwal, LinkedIn


Christopher Re, Stanford University

Bill Cleveland, Purdue University

Panel Discussion:

Roger Barga, Microsoft Corporation

Ron Brachman, Yahoo

Mark Ryland, Amazon

 11:00-11:15  Break

11:15-1:00  Panel Discussion: Workshop Lessons

 Chair: Rob Kass, Carnegie Mellon University

 1:00  Adjourn


The difference between carving and filling (3)

Interesting to see the “energy” concept, which seems similar to the least-cost algorithm. Will check it out. Thank you!


In my last posts I wrote about carving and filling. As noted, both algorithms are implemented in the constructor function FLOWobj and thus are primarily used to derive flow directions through topographic depressions. These options, thus, don’t change the DEM itself. In this post, I will show how you will carve and fill the DEM.

Filling is easy and implemented in most terrain analysis software. A number of different algorithms exist that perform flood-fill operations; in our paper, Dirk and I compared processing speeds to fill an image. We found that the speed at which one and the same DEM is filled varies widely between different software. The Matlab’s image processing toolbox’s function imfill (the function that is called by TopoToolbox function fillsinks) outperforms other software by 8-10 times faster processing speed. However, I like to stress that speed is not the only indicator of performance and that other…

View original post 275 more words

How to configure Eclipse for ArcPy

  1. Download and install Eclipse
    1. Download Eclipse standard version: 
    2. Extract the downloaded zip file, copy the unzip “eclipse” folder to C:\Program Files\.
  2. Install PyDev for Eclipse
    1. Go to Eclipse –> Help –> Install New Software
    2. Enter in the Work with:  field.
    3. After several seconds, two options should appear. Select the PyDev for Eclipse option. Do not select the “PyDev Mylyn Integration” flag.
    4. Click “Next” and “OK” to continue installing PyDev
  3. Configure PyDev
    1. Go to Window → Preferences. In the Preferences window, expand PyDev and select Interpreter-Python.
    2. Click “New…” and type Python27 for the Interpreter name. For the Interpreter executable, browse to your copy of Python C:\Python27\ArcGIS10.2\python.exe), and press Open.Image
    3. Click “OK” and the  Selection Needed Window will appear.Image
    4. Click “Select All” and “OK”.
    5. The Interpreter is now set up so that the code you write can be interpreted for the computer to run. You are now ready to start running code.
  4. Open Perspective as PyDev
    1. Go to Eclipse –> Window –> Open Perspective –> Other
    2. Select PyDev on the Open Perspective Dialog
    3. Image

ArcGIS Online Spatial Analysis Live Training Seminar

ArcGIS Online is a powerful platform for analyzing data. New spatial analysis tools are being continually added to help you solve common spatial problems. If you would like to learn more about online analysis, tune into the live training seminar Spatial Analysis with ArcGIS Online on May 15, 2014.

ArcGIS Online Spatial Analysis Live Training Seminar.

The difference between carving and filling (1)


People using TopoToolbox asked me quite frequently about the difference between the two preprocessing options when calculating a flow direction object (FLOWobj): ‘carve’ and ‘fill’.

First and most important: These options do not alter the DEM, they only control how FLOWobj internally preprocesses the DEM to optimize how flow is routed through topographic depressions.

In this first post I’ll describe how the option ‘fill’ works.

Option ‘fill’: The constructor function FLOWobj fills all topographic depressions (function fillsinks). It then identifies all flat sections (function identifyflats) and calculates an euclidean distance transform (function bwdist) within each flat section seeded at their outer rim. Subsequently, the complement of the distance transform is calculated in each flat area. The complement grid is subsequently used as weights in a gray-weighted distance transform (function graydist). This generates an auxiliary surface in each flat area. The surface has the nice property that flow will run through…

View original post 75 more words

SRTM DEM data downloader in Whitebox GAT

A new great tool in Whitebox GAT

Whitebox Geospatial Analysis Tools

I just finished developing a tool for Whitebox GAT that will automatically download Shuttle Radar Topography Mission (SRTM) digital elevation models (DEMs) from the USGS SRTM FTP site. SRTM-3 data are among the best global elevation data, with a grid resolution of approximately 90 m. In many areas SRTM data provide the only topographic data set available. Within the United States, the SRTM-1 dataset provides an improved 30 m resolution. Not only does this Whitebox tool retrieve the SRTM tiles contained within the bounding box of a specified area of interest, but it will also import the tiles to Whitebox GAT, fill missing data holes (which are common with SRTM data in rugged terrain) and mosaic the tiles.

Whitebox's new Retrieve SRTM Data tool Whitebox’s new Retrieve SRTM Data tool

There have been many times in the past when I have needed to download numerous SRTM files, import the files, fill the missing data holes, and finally mosaic the…

View original post 178 more words

Alex Tereshenkov

Programming and managing GIS

REDD+ for the Guiana Shield

Technical Cooperation Project

Dr. Qiusheng Wu @ University of Tennessee

Writing Science

How to write papers that get cited and proposals that get funded

GIS In Ecology

Providing Training, Advice And Consultation On The Use Of GIS In Ecology


On cities, land, ...

Scientia Plus Conscientia

Thoughts on Science and Nature


Learning hydrology with R

Karl Hennermann

GIS at the University of Manchester

GIS and Science

Applications of geospatial technology for scientific research and understanding.

Whitebox Geospatial Analysis Tools

Open-source GIS development and spatial analysis with Whitebox GAT


MATLAB-based software for topographic analysis

Anything Geospatial

Dr. Qiusheng Wu @ University of Tennessee

Dr. Qiusheng Wu @ University of Tennessee

Another GIS Blog

Dr. Qiusheng Wu @ University of Tennessee

ArcPy Café

Get all your ArcGIS Python Recipes here!