10 December 2010

That s quite impressive.

Battery and power4

  • Built-in 25-watt-hour rechargeable lithium-polymer battery
  • Up to 10 hours of surfing the web on Wi-Fi, watching video, or listening to music
  • Up to 9 hours of surfing the web using 3G data network
  • Charging via power adapter or USB to computer system
4.Testing conducted by Apple in March 2010 using preproduction iPad units and software. Testing consisted of full battery discharge while performing each of the following tasks: video playback, audio playback, and Internet browsing using Wi-Fi or 3G. Video content was a repeated 2-hour 23-minute movie purchased from the iTunes Store. Audio content was a playlist of 358 unique songs, consisting of a combination of songs imported from CDs using iTunes (128-Kbps AAC encoding) and songs purchased from the iTunes Store (256-Kbps AAC encoding). Internet over Wi-Fi and 3G tests were conducted using a closed network (for Wi-Fi only) and dedicated web and mail servers, browsing snapshot versions of 20 popular web pages, and receiving mail once an hour. All settings were default except: Wi-Fi was associated with a network (except for Internet browsing over 3G); the Wi-Fi feature Ask to Join Networks and Auto-Brightness were turned off. Battery life depends on device settings, usage, and many other factors. Battery tests are conducted using specific iPad units; actual results may vary.

Xiaoyu Guan (Sam)

most of geo-apps are instantly require gps signals, then the smartphone can stand for few hours, I think most of phone less than 5 hours. 
If you do a lot of web page viewing, photo taken, display always on. the smartphone will be useless.
Or for professional user, they need extra battery for smartphone phone.

Here is nice article

Smartphone Battery Life

Have a backup handy--either a spare battery for a case with a built-in battery.
Most phones pack in Lithium-ion battery, or Li-ion, ranging between 780mAh and 1200mAh. Phone batteries have a limited number of charge and discharge cycles, usually falling between 300 and 500. Beyond this lifespan, batteries gradually diminish below 50 percent of its original capacity. Whichever way you look at it, you'll probably need a new phone battery each year. Vendors shipped phones with proprietary chargers in the past that only worked with a specific phone. However, most newer phones ship with a USB charger for AC power that can be used with any phone, provided you have a cable with the standard USB connector on one side and a connector for your phone model on the other. Some phones ship with an extra battery and others, like the iPhone, sport a sealed-in battery that Apple replaces for a $79 fee. Battery life and charge cycles vary by the operating system, phone settings, network type (WiFi, CDMA/GSM, 2G/3G), and programs used.
Smartphones require lots of juice
Dumb phones (low to mid-end) provide around 400 hours of standby time and more than ten hours of talk time. Smartphones, however, are essentially tiny laptops that have lots more going on inside them than ordinary phones. Hence, they draw more juice. High-end smartphones provide up to ten hours talk time and up to 300 hours standby time. A typical smartphone features around five hours talk time on 3G (2-3 times more on 2G) and 150 hours standby time. However, these figures drop sharply when you play media and games or surf the web. Whichever way you look at it, you should buy a reserve battery because a typical smartphone won't carry you through the work day on a single charge. Business users who travel a lot should buy extras like car adapters and traveler kits. When evaluating a new phone, check its rated battery life and pay attention to testing conditions. For example, vendors usually conduct battery tests with 50 percent brightness, WiFi turned off, and no media playback. These settings skew the battery life unrealistically and rarely reflect real-life usage scenarios.
Buyers should note that some phones have removable batteries and some don't. While this isn't a major feature for most people, and lots of buyers will value the slim designs allowed by non-removable batteries, it is something to keep in mind. If you are a heavy phone user who makes a lot of calls and sends emailsconstantly, then you might want to keep a spare battery on hand. Many phones, like the iPhone, have cases available with built in batteries, but they add a bit of size and weight to the device. They are a good work-around, but they might not be exactly what demanding users are looking for.

Xiaoyu Guan (Sam)

OpenWater Symposium

Dear MapWindow Announcements List,

Because we have a large water modeling user group within the MapWindow community, I'm forwarding you this announcement about a workshop in Delft, Netherlands, April 18-19, 2011.

I will be presenting a workshops on MapWindow, DotSpatial, and HydroDesktop at this meeting. Please come join us!

Also remember that we are having the 2nd International MapWindow Users and Developers Conference in San Diego, California, June 13-15, 2011.

- Dan


Dear colleagues,

kindly be invited to the OpenWater symposium and workshops that takes place during the days April 18-19, 2011 and is hosted by the UNESCO-IHE Institute for Water Eduction, Delft, Netherlands.

The OpenWater symposium and workshops aim at sharing experiences for increasing the interoperability of new emerging ITC based systems, systems of systems and standards in the water domain. Several initiatives are currently taken to initiate open standards and interfaces under GEO, OGC, OpenMI association  and several research projects. OpenWater will be organised as series of invited presentations, dedicated workshops (MapWindow, SWAT-CUP, SDI, bringing GEOSS into practice...), and oral / poster presentations. Abstract are welcomed till January 15 2011 in the following areas:

Web services & OGC standards
Integrated modeling systems
Data transfer standards and  systems
Remote sensing and sensor observations
Mobile devices and information systems
Open source developments
Interoperability experiments
Interoperability in European  research and developments

More information can be obtained at: http://hikm.ihe.nl/openwater_eg/

Please forward this information to colleagues that might be interested to attend.

Kind regards,

Ann van Griensven

Dr. ir. Ann van Griensven
Associate Professor in Environmental Hydroinformatics
Department Hydroinformatics and Knowledge Management
UNESCO-IHE Institute for Water Education
P.O. Box 3015, 2601 DA DELFT, The Netherlands
Visiting address: Office W.321, UNESCO-IHE, Westvest 7, 2611 AX Delft, NL
tel +31 15 215 18 12
e-mail a.vangriensven@unesco-ihe.org

Daniel P. Ames, Ph.D. PE
Associate Professor, Geosciences
Idaho State University - Idaho Falls

Announce mailing list
MapWindow GIS Mailing Lists:

Xiaoyu Guan (Sam)

18 September 2010

The following are the steps for configuring the FTP on Windows 7 with Filezilla :
  1. The first time you have to change the admin password to edit>> preferences Administrator>> administrator password.
  2. After that you already have an FTP server running on Windows 7.
  3. You could use a manual connection or filezilla FTP client. To proceed you need a newly created user in the different FTP server admin, for safety.
  4. The users simply Agregat icon you in this case the user is Opensys and the key is opensysblog, add a password and give permissions to a folder in the Shared Folders menu, look for it and give read / write permissions.
  5. Save the changes and we tested.
  6. Start>> Run>> cmd, type ftp localhost "or the ip of the machine".
source link

Xiaoyu Guan (Sam)

27 August 2010

MapProxy Project for Accelerating your WMS

There are a few Open Source WMS caching proxys that are freely available for anyone to download and use. GeoWebCache and TileCache have been the two leaders in the MapCache game for a while now. The problem with these is that they only output WMS-C which most WMS readers can't read. MapProxy can ingest WMS, TMS and KML thenspit it back out as a valid WMS service so that ALL modern GIS clients can read it.
I just setting up OSM into Tilecache as TMS.
From above information, I think I need mapproxy, if i want to turn the TMS into WMS


Features of MapProxy

MapProxy acts as a WMS, TMS and KML server. It does not render any data itself but delegates requests to other server. It stores all responses and reuses that cached data for further requests. It can requests data from WMS and TMS clients.
MapProxy supports:
MapProxy can:
  • accelerate existing WMS
  • reproject to other SRS (i.e. cache in EPSG:4326, requests in EPSG:31467)
  • combine individual map layers from different WMS services
  • hide the origin WMS servers
  • fill caches dynamic, in advance or both
  • add watermarks and/or attributions to all responses

Xiaoyu Guan (Sam)
I just found one great tutorial for rendering osm in custom projection.
The tutorial is locate at http://www.justobjects.org/blog/?p=45
It covers import raw data to PostGIS. and setting up Mapnik osm.xml with right projections.
Last but not least, how to setting up tilecache with mapnik.
then you can use seed tool from tilecache to cache all the layer in your own projections.
or you can try to rewrite seed tool from mapnik. but the tool is default for projection 4326. you have to modify the script.
There is some differences between these tools, the tool from mapnik or osm community is store all tiles in standard XYZ folders.
so you can render the cache via OL xyz layer.
The cache from Tilecache is stored in tilecache own name convention.The cache is not store in standard XYZ tiles.
You cannot render tilecache cache file viw OL default XYZ layer.  At least I tried and failed.
For more details, better check Just' tutorials.

Xiaoyu Guan (Sam)

17 August 2010

As you know, there is OSM SLD from FlorentDotMe.
Last time, I did not success for rendering osm data using the sld.
but this time, I made it.
Here is some screen dump from FlorentDotMe SLD.
I use original OSM data of Netherlands, projection 28992.
The import tools is osm2pgsql, then reprojection the whole database to 28992.

check attached images for more detail.

personally, the sld is quite good but not same quality as mapnik style.

08 July 2010

Authentication failed

If you can't connect to postgres with the psql command (this happens, for example, with Ubuntu 9.10 and postgres 8.3):
$ psql -W gis username
psql: FATAL:  Ident authentication failed for user "username"
Even after you've set the password for the user:
$ sudo -u postgres -s -H
postgres@aoeu$ psql 
Welcome to psql 8.3.5, the PostgreSQL interactive terminal.
ALTER ROLE username PASSWORD 'mypassword';
You may have to append the following lines to your pg_hba.conf (found e.g. in /etc/postgresql/8.3/main):
local   all         all                               trust   
host    all         all          trust
host    all         all         ::1/128               trust
So that you can use password authentication from localhost.
Note that you may have to comment out any existing lines beginning with local all or host all. I had to comment out the following section on Ubuntu 8.40:
# "local" is for Unix domain socket connections only 
#local   all         all                               ident sameuser
# IPv4 local connections:
#host    all         all          md5
# IPv6 local connections:
#host    all         all         ::1/128               md5


Xiaoyu Guan (Sam)

06 July 2010

step 1: install postgresql 8.4 with postgis 1.3 via synaptic package manager
step 2: open root terminal,
run sudo su postgres -c psql postgres
then alter user with password 'YOURPASSOWRD';

step 3: open your pgadminIII, with postgres account.
 postgresql is ready for you now.

Xiaoyu Guan (Sam)

27 June 2010

if you download latest iOS SDK(3.2), you will got the ipad
but if you want to develop some iOS apps, you still need a mac developer account(which is not free).
to support multitouch function, you need a track pad which should support multi-touch. such as

Wacom Bamboo Pen & Touch

Xiaoyu Guan (Sam)

21 June 2010

How to built save feature for WFS?

Dear All:
I try to built my own WFS server , I have Featureserver + mod_python +postgis on my local pc.
If I use OpenLayers.Control.ModifyFeature(wfs) method, how can I catch the modified feature and post it to FS?
I try to collect all features from wfs layer, and send it back to featureserver. it doesn't work.
I have already try some example from OL examples . and I could not find a lot of information about it in ol maillinglist.
It would be thanksful that somebody can point out where I should go.
Here is some code from my:

            drawControls = {
                    point: new OpenLayers.Control.DrawFeature(vectors,
                    line: new OpenLayers.Control.DrawFeature(vectors,
                    polygon: new OpenLayers.Control.DrawFeature(vectors,
                    editPolygon:new OpenLayers.Control.ModifyFeature(wfs, {
                        title: "Modify polygon"}))

var arr = [];
            var j = 0;
            for(var i =0; i<wfs.features.length;i++){
                if(wfs.features[i].gml.featureType == "polygon"){
                    arr[j] = wfs2.features[i];
            json = geojson.write(arr);

            new OpenLayers.Ajax.Request(url,
                     {   method: 'post',
                         postBody: json,
                         requestHeaders: ['Accept', 'application/json'],
                         onSuccess: success,
                         onFailure: function(xhr) {
                           $('info').innerHTML = "Failed upload (status code "+xhr.status+"). Check your URL."

all the best


19 June 2010

Steve Jobs broke his promise: Mac mini is not the most affordable mac

As everybody knows, Apple computer is always more expensive than other brand computers.
For my understanding, one is Apple's creative and cool hardware design; another one is you are paying for one smart operating system which little smarter than Windows OS and Linux OS.

The CEO of Apple , Steve Jobs, said Mac mini is the most affordable mac which they ever can deliver/ produce. it was in 2006, and it cost 499 USD.
now today, Apple selling Mac mini in euro at 799EURO. It seem like Apple has different defition of ''affordable''.

Actually, I am one mac mini user. I bought one last year, it was 599 euro. now with 200 euro what you can get.
a little faster cpu, a little bigger memory , a bigger harddisk, with some extrac feature, one SD card reader and HDMI,
if we look on the market, 800 euro you can get some pc have same level performance as mac pro, in my opinion.
Mac mini is not the most affordable mac any more.
I think macbook even better than mac mini. If want to get a mac, I will go to macbook.

Xiaoyu Guan (Sam)

10 June 2010

new book: PostGIS in Action $29.99

today, I saw there is new postgis book going to publish. it cost $29.99 for ebook
book information

Manning Early 
Access Program
PostGIS in Action

Regina O. Obe and Leo S. Hsu

MEAP Began: May 2009
Softbound print: September 2010 | 425 pages 
ISBN: 9781935182269

Pre-Order options*
Order today and start reading PostGIS in Action today through MEAP
  MEAP + Ebook only - $29.99
  MEAP + Print book (includes Ebook) when available - $49.99
* For more information, please see the MEAP FAQs page.
  About MEAP Release Date Estimates      


Table of Contents         Resources 
PART I - Learning PostGIS 
 1. What is a spatial database? - FREE 
 2. Geometry types - AVAILABLE 
 3. Data modeling - AVAILABLE 
 4. Geometry functions - AVAILABLE 
 5. Relating two or more geometries - AVAILABLE 
 6. Special reference system considerations - AVAILABLE 
 7. Working with real data - AVAILABLE 

Part 2 Putting PostGIS to work 
 8. Techniques to solve spatial problems - AVAILABLE 
 9. Performance tuning - AVAILABLE 

Part 3 Using PostGIS with other tools 
10. Enhancing SQL with add-ons - AVAILABLE 
11. Using PostGIS in web applications - AVAILABLE 
12. Using PostGIS in a desktop environment - AVAILABLE 
13. PostGIS WKT Raster - AVAILABLE 

Appendix A Additional resources - AVAILABLE 
Appendix B Installing, compiling, and upgrading - AVAILABLE 
Appendix C SQL primer - AVAILABLE 
Appendix D PostGreSQL features - AVAILABLE


Whether you're canvassing a congressional district, managing a sales region, mapping city bus schedules, or analyzing local cancer rates, thinking spatially opens up limitless possibilities for database users. PostGIS, a freely available open-source spatial database extender, can help you answer questions that you could not answer using a mere relational database. Its feature set equals or surpasses proprietary alternatives, allowing you to create location-aware queries and features with just a few lines of SQL code.

PostGIS in Action is the first book devoted entirely to PostGIS. It will help both new and experienced users write spatial queries to solve real-world problems. For those with experience in more traditional relational databases, this book provides a background in vector-based GIS so you can quickly move to analyzing, viewing, and mapping data. Advanced users will learn how to optimize queries for maximum speed, simplify geometries for greater efficiency, and create custom functions suited specifically to their applications. It also discusses the new features available in PostgreSQL 8.4 and provides tutorials on using additional open source GIS tools in conjunction with PostGIS.


  • An introduction to spatial databases
  • The basics of geometry types, functions, and queries
  • Ways to solve real-world problems
  • Methods to extend PostGIS to web applications and desktop environments


Regina Obe and Leo Hsu are a wife and husband team of database specialists who have been actively involved in the PostGIS community since 2002. Regina is a member of the PostGIS core development team and the Project Steering Committee. Their company, Paragon Corporation, was founded in 1997 and has provided database and GIS solutions for a broad range of clients. They also host two sites: BostonGIS.com and PostgresOnline.com.


"What truly unifies this book is the clarity and purpose of writing. Wherever the subject matter becomes abstract or difficult to grasp the authors have gone to great lengths to break the problem down into attainable steps, providing clear and patient guidance throughout."
Mark Leslie, Software Architect, LISAsoft Pty Ltd

"This book addresses a problem I have run into repeatedly in my consulting work: educating database professionals (DBAs, developers, etc.) on working with spatial data in a manner that they are familiar with. The authors are extremely knowledgeable about database technologies of all kinds and it comes through here."
William Dollins, Senior Vice President, Zekiah Technologies, Inc.


This Early Access version of PostGIS in Action enables you to receive new chapters as they are being written. You can also interact with the authors to ask questions, provide feedback and errata, and help shape the final manuscript on the Author Online


Sign up to read more content when it is released and to receive news about this book. 

Xiaoyu Guan (Sam)