09/04: Change of URL
As announced in February, the old virtual server with the URL www.disk-world.de will be off soon. The date is now fixed as 22.04.2006.
I may, however, shift the domain name to my current provider.
Until then, please go to www.wr-man.net/rwsd to access the database application and the weblog of Tanzania Rural water Supply Department.
I may, however, shift the domain name to my current provider.
Until then, please go to www.wr-man.net/rwsd to access the database application and the weblog of Tanzania Rural water Supply Department.
The new site for LCBC (Lake Chad Basin Commission) used PHP code initially developed for RWSD. However, some new features were added and some bugs fixed. These code improvements will now be fed back to the RWSD code. However, we will keep MySQL and GIS data stored as ESRI Shape files.
In the next step, we installed the RWSD database site also under Fedora 3, the new location will be accessible under www.wr-man.net/rwsd. This is functional since 3rd February 2006!
However, for a certain period the RWSD database will be available under both URLs (i.e. also under the current www.disk-world.net).
In the next step, we installed the RWSD database site also under Fedora 3, the new location will be accessible under www.wr-man.net/rwsd. This is functional since 3rd February 2006!
However, for a certain period the RWSD database will be available under both URLs (i.e. also under the current www.disk-world.net).
After 2 months of development work, the new web page for LCBC is now operational. That site is based on the development work made for RWSD, but with a few but essential differences:
- The database is PostgreSQL instead of MySQL
- Geographic data used by MapServer are stored in the same PostgreSQL database and not in external shapefiles
- Based on available monitoring data, charts are produced by the web server according to user specifications
- The webserver runs under Fedora 3 instead of Red Hat 7 - because the old Linux distribution did not permit a newer version of PostgreSQL
The HTML pages shown by your browser are dynamically generated by PHP (PHP Hypertext Processor). The comprehensive documentation of the PHP program source code for the RWSD database application has been uploaded now to this web site and is available online now. This documentation has been produced in the following steps:
On demand, I can also email the latest CHM-file as a single file - to have all documentation together in a single file.
- Goce added comments to the original PHP code. This was the most work intensive part
- Using an open source program called phpDocumentor the documentation with all its links was generated as CHM-helpfile
- Klaus decompiled the CHM-helpfile, corrected wrong links (caused by a bug in phpDocumentor), added a header page, modified the table of contents in “HTML Help Workshop” and recompiled it again.
- Than Klaus used a shareware program called chm2web to transform the CHM-file into an online help system with a nice navigation
On demand, I can also email the latest CHM-file as a single file - to have all documentation together in a single file.
Fortunately, Open Source software is also advancing in the GIS sector. Quantum GIS is still in beta phase (the current version is 0.7) but already fairly stable and really fast even when processing large data sources. Some features (like the semi-transparent display of raster files, dashed borders of polygons and “halos” around labels) are features users always requested for ArcView and only got it finally in ArcGIS – nor now with Quantum GIS.
Quantum GIS can not only read ESRI Shapefiles and Coverages as well as MapInfo files but also geographic data saved in PostgreSQL. I am currently experimenting with PostgreSQL as it appears also the ideal data storage for our Mapserver. The “on-the-fly-projection” for vector files is another feature supported by QuantumGIS. It is also supported by ArcGIS but not by the old ArcView 3.x. Quantum GIS is available for Windows, Linux (Debian, Mandriva, Suse), Apple and Free BSD.
Last not least, for Quantum GIS a number of plug-ins are available which permit advanced data management and modelling tasks interesting fo the assessment and management of natural resources.
But beware! The openModeller Wizard may not load, and SPIT (the Shapefile to PostGIS Import Tool) may spoil your ArcGIS data sources. I received first an error message under SPIT “problem inserting features from file” and than the data were also not any more acessessible from ArcGIS. Only after I loaded them from ArcView and exported them to a new shapefile I could import them to PostGIS and load them into ArcGIS as well.
Quantum GIS can not only read ESRI Shapefiles and Coverages as well as MapInfo files but also geographic data saved in PostgreSQL. I am currently experimenting with PostgreSQL as it appears also the ideal data storage for our Mapserver. The “on-the-fly-projection” for vector files is another feature supported by QuantumGIS. It is also supported by ArcGIS but not by the old ArcView 3.x. Quantum GIS is available for Windows, Linux (Debian, Mandriva, Suse), Apple and Free BSD.
Last not least, for Quantum GIS a number of plug-ins are available which permit advanced data management and modelling tasks interesting fo the assessment and management of natural resources.
But beware! The openModeller Wizard may not load, and SPIT (the Shapefile to PostGIS Import Tool) may spoil your ArcGIS data sources. I received first an error message under SPIT “problem inserting features from file” and than the data were also not any more acessessible from ArcGIS. Only after I loaded them from ArcView and exported them to a new shapefile I could import them to PostGIS and load them into ArcGIS as well.
24/09: Link to Swahili dictionary
In Tanzania, the most widely spoken language is not English but Swahili. The dynamic page generation would make a bilingual web site for the RWSD data base not too difficult - particularly, as Swahili is written in standard Latin characters.
For anyone looking for an online Swahili-English or English-Swahili dictionary, here is a link to a useful site, the Internet Living Swahili Dictionary or “Kamusi Project” of Yale University.
For anyone looking for an online Swahili-English or English-Swahili dictionary, here is a link to a useful site, the Internet Living Swahili Dictionary or “Kamusi Project” of Yale University.
30/06: Website access problems
During the last 2 weeks, our web hosting company ISP4P had been forced to restart their servers a few times. Our virtual servers that are based on them are running Apache web server and MySQL data base; these are responsable to generate the pages you are seeing on the domain www.disk-world.de. Unfortunately, Apache and MySQL did not restart automatically but had to be started manually, causing times of being not accessable.
Today (30th June 2005) new scripts were put on our virtual server. Now, after every reboot of the server Apache and MySQL should restart automatically.
Today (30th June 2005) new scripts were put on our virtual server. Now, after every reboot of the server Apache and MySQL should restart automatically.
31/05: Latest Program Improvement
On 30th May 2005, a new program version has been uploaded to www.disk-world.de.
The structure of the database is such that “data on scheme level” and “relation of resources to schemes” depend on the definition of schemes (with address and related villages).
Maintaining these relations is now controlled by so-called “foreign keys”. Databank users with administration rights can test this by trying to delete some scheme that is already referenced in some of the scheme detail tables. The user should be informed about the inconsistencies that the requested data operation will cause. Pay a special attention on the treatment of resources and pumps. The FK validation prevent modification of PK (primary key) and deletion of a referenced row.
The structure of the database is such that “data on scheme level” and “relation of resources to schemes” depend on the definition of schemes (with address and related villages).
Maintaining these relations is now controlled by so-called “foreign keys”. Databank users with administration rights can test this by trying to delete some scheme that is already referenced in some of the scheme detail tables. The user should be informed about the inconsistencies that the requested data operation will cause. Pay a special attention on the treatment of resources and pumps. The FK validation prevent modification of PK (primary key) and deletion of a referenced row.
19/05: Correction of Weblink
The wrong link in the database application to GTZ has finally been corrected (the link behind the GTZ-Logo).
Due to the structure of the database, only a single file (rwsd_screen.php) needed modification.
Due to the structure of the database, only a single file (rwsd_screen.php) needed modification.
The Project in Dar es Salaam is using Total Commander as file Management software under Windows. Recently, a new update became available, Version 6.52 - and now, in June, even another bug fix, 6.53. Please download the installation file and run it on each project computer. The project licenses are still valid for updates.
