sdteffen's blog

PHP support added to the Google App Engine

noreply@blogger.com (Steffen Macke) — Fri, 17 May 2013 20:25:00 +0000

Google has announced PHP support for their App Engine: Read more in a Cloud Platform Blog post.

GHydraulics 2.1.0: Handle missing junctions, duplicate ids, multipart pipes

noreply@blogger.com (Steffen Macke) — Fri, 29 Mar 2013 11:13:00 +0000

GHydraulics version 2.1.0 has been released with additional checks and capabilities to deal with typical problems like missing junctions, duplicate ids, coordinate reference system consistency and multipart pipe shapes. The menu item "Check Model" that was introduced in version 2.0.9 has been removed, the checks are performed when "Make EPANET Model" is selected (I think that this is more user friendly).
Sample data played a key role in the development of the current version - if your data does not create working EPANET models, please don't hesitate to share it with me in order to iron out the remaining problems.

GHydraulics is an open source QGIS plugin that allows to create EPANET hydraulic analysis models. It's a regular topic in this blog. Check the GHydraulics label for related future and past blog posts. These blog posts are the GHydraulics documentation and will tell you how to operate the software successfully.

Donations and expenses for dia-installer.de in 2012

noreply@blogger.com (Steffen Macke) — Sun, 24 Feb 2013 17:49:00 +0000

I've updated the dia-installer.de's donation page with information from 2012. Thanks to all donors! In case you would like to direct my open source directions in a different direction: epanet.de also has a donation page. Be the first to donate!

Block 223512 is getting close: There's still a chance to win the "SAP ABAP Advanced Cookbook" eBook

noreply@blogger.com (Steffen Macke) — Sat, 23 Feb 2013 19:05:00 +0000

This is a reminder for the Advanced ABAP Cookbook post. Bitcoin Block 223512 is getting close and until now nobody wanted to participate. It's not complicated. I just need an email that I can pass on to Packt Publishing so that they can issue the eBook for you. You have a really good chance! And if you're not interested in this matter, think of a friend who might be. Email me a sdteffen at gmail dot com if you want. Looking forward to more participants this time...

GHydraulics 2.0.9: Bugfix and maintenance release

noreply@blogger.com (Steffen Macke) — Sat, 23 Feb 2013 18:49:00 +0000

GHydraulics version 2.0.9 has been released with a couple of bug fixes and robustness improvements. In addition. a new "Check Model" function is available. Currently it just checks if all required fields are available. It can automatically add the missing fields, if you want. Future versions will add more validation logic to this function.
GHydraulics is an open source QGIS plugin that allows to create EPANET hydraulic analysis models. It's a regular topic in this blog. Check the GHydraulics label for related future and past blog posts.

epanet.js - JavaScript version of EPANET

noreply@blogger.com (Steffen Macke) — Tue, 12 Feb 2013 21:57:00 +0000

A first version of epanet.js, the JavaScript version of EPANET is available: epanet.de/developer/epanetjs.html That's pretty interesting for those that would like to analyze water supply networks without installing software. All data is kept in the browser, nothing is send to the server. Right now you'll have to cut'n'paste your favorite INP files using a text editor into the input field or edit the INP file manually. But a graphical interface is definitely possible. It also adds JavaScript as a programming language that you can use EPANET in your own code (besides C, C++, Java, Visual Basic, MATLAB, Python - in case I missed a language here, please let me know). Source code is available on github. The page is 200kB - 1.2 MB in Size, if your internet connection is slow or your hardware is old, things might be slow.

iD Open Street Map Editor

noreply@blogger.com (Steffen Macke) — Thu, 07 Feb 2013 21:04:00 +0000

There's a new Open Street Map Editor, written in JavaScript: iD. It uses D3.js and looks very promising to me - especially the line-node topology handling. What do you think?

Save the elephants: PostgreSQL 9.2.3

noreply@blogger.com (Steffen Macke) — Thu, 07 Feb 2013 19:08:00 +0000

PostgreSQL 9.2.3 fixes (among other things) a security hole that allowed DoS attacks on PostgreSQL servers. Read more in the PostgreSQL 9.2.3 release notes.

Win the eBook version of "SAP ABAP Advanced Cookbook"

noreply@blogger.com (Steffen Macke) — Thu, 31 Jan 2013 20:26:00 +0000

Packt Publishing allows me to give away three free eBook copies of Rehan Zaidi's "SAP ABAP Advanced Cookbook". I would like to use a kind of Bitcoin block lottery for this: If you would like to participate, comment on this post or email sdteffen at gmail.com with a pseudonym and a contact email address. For the winners, I'll have to hand this over to Packt Publishing in order to get the eBooks distributed. You can also choose your lucky token - one of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e or f. Winners will the ones with the tokens that appear first in the hash of Bitcoin block 223512 - it'll be computed in something like 30 days and I'll post a link once it's done. The leading zeros will be stripped, so 0 is less likely to win. You can use Bitcoin Block Explorer to view the hash.
As an example, here's block 218911 - as you can see, it has the following hash:
00000000000003731e16ecada579f6c50ca0f00bb3ea0b3f076eac546fd74b5a
The tokens 3, 7 and 1 would be the winners in this sample.
Good luck!

I've already announced the book in a blog post and explained, why I'm "in there". Here's what's inside: 316 pages split into 15 chapters with tutorial style "recipes" that cover a broad variety of topics related to programming with the powerful ABAP programming language and the underlying systems. As the adjective "advanced" suggests it's not an introduction to ABAP programming. But with basic knowledge and the will to "do more", you'll find solutions for many aspects related to software development: Object orientation, regular expressions, performance optimization, debugging, query optimization, efficient form design, various import and export formats, web services, office integration...
And of course, a "cookbook" is impressive even to your friends that are not into software development (This happened to me two days ago). Take the chance to fill up your digital bookshelf!

The small print: I don't own the copies of the book, I can only hand over the three email addresses to Packt Publishing. Please don't blame me, if things don't work out as expected. I'm only the messenger. In case your lucky token is taken already and there's one left, I'll assign one for you. I'll not use your email address unless you're a winner and then only to notify you of your win. In case there are many participants applying at the same time, those who've commented in the blog will be given priority. Why do you have to provide a pseudonym? I would like to make the process as transparent as possible (even if it's very technical - the audience are software developers) and show which tokens are taken already. A big thanks to Packt Publishing for giving me this opportunity If you feel like it, you can also make a guess when block 223512 will actually be calculated. For Germans: Der Rechtsweg ist ausgeschlossen.

GHydraulics 2.0.8: Fill the fields NODE1 and NODE2

noreply@blogger.com (Steffen Macke) — Tue, 22 Jan 2013 19:41:00 +0000

GHydraulics 2.0.8 is out with a new "Make EPANET Model" function that will (re)fill the NODE1 and NODE2 fields of your line themes.

These fields make up the "topology" of your EPANET model. The describe how lines and nodes are connected.
If you would like to testdrive the new function, I suggest that you follow the instructions I've posted for version 2.0.7 (Write complete EPANET models from QGIS).
Once you've done that, make your model "loose" the topology:

Start editing the pipes theme
Open the attribute table
Use the field calculator to update the field "NODE1" with the expression '' (empty it)
Repeat this step for the field "NODE2"

A look to the pipe attribute table should show that all NODE1 and NODE2 fields are empty now.

Once you've done that, choose Plugins->GHydraulics->Make EPANET Model from the menu. The fields NODE1 and NODE2 will be filled again with DC_ID values from the respective node themes.

Users of the DC Water Design Extension should be pretty much used to this approach. Once you've successfully mastered model making with the sample data, try your skills with your own data.

GHydraulics is not finished. The GHydraulics label in this blog allows you to stay up to date with the latest developments. There's a number of automated checks and fixes that should be implemented in future versions. Stay tuned. And remember that your feedback and error triggering sample data is required in order to streamline and improve GHydraulics. I'm looking for for your feedback!

Early Access: Save 50% on "PostGIS in Action, Second Edition"

noreply@blogger.com (Steffen Macke) — Sat, 19 Jan 2013 08:16:00 +0000

The week of books continues: James Fee posted a coupon code on Spatially Adjusted that'll save you 50% on the second edition of "PostGIS in Action" if you use it until January 22, 2013.

This is an "early access edition", you'll not find it yet on Amazon. I'm currently reading the first edition and find it really useful.

Dia mentioned in "Pattern-Oriented Software Architecture for Dummies"

noreply@blogger.com (Steffen Macke) — Wed, 16 Jan 2013 18:22:00 +0000

Another book, another topic: Dia is mentioned in chapter 3 of Robert Hammer's book "Pattern-Oriented Software Architecture for Dummies". It can be fun to learn how you can use Dia to layout your software architecture!

Rehan Zaidi's "SAP ABAP Advanced Cookbook"

noreply@blogger.com (Steffen Macke) — Tue, 15 Jan 2013 20:40:00 +0000

Two days ago I received my printed copy of Rehan Zaidi's "SAP ABAP Advanced Cookbook". I was pretty excited, because this was the first time I've participated in the production process of a book (as a reviewer/proofreader). I enjoyed this very much and learned a lot of things (e.g. book creation is a lot of work).
If you would like to learn more of the ABAP programming language, have a look at Rehan's recipes - both the Amazon and Packt Publishing pages contain some "previews":

Beware of the phpMyAdmin backdoor

noreply@blogger.com (Steffen Macke) — Tue, 25 Sep 2012 18:36:00 +0000

Today a phpMyAdmin backdoor became public (looks like one of the Sourceforge mirrors was corrupted). Details can be found in the SourceForge blog.

Potential data corruption fix: PostgreSQL 9.2.1

noreply@blogger.com (Steffen Macke) — Mon, 24 Sep 2012 15:55:00 +0000

PostgreSQL 9.2 is still young, but there's already a handful of fixes, bundled in the 9.2.1 release. Detailed information can be found on www.postgresql.org/about/news/1416/

Feedburner burns no more: Email subscription problem

noreply@blogger.com (Steffen Macke) — Mon, 24 Sep 2012 15:51:00 +0000

Google has pulled the plug on Feedburner (or at least the API part of it). At the moment, I'm not sure if posts still reach those who have subscribed via Feedburner/email. For some of you, www.feedmyinbox.com might be an alternative. But I'm still hesitant to add a new "Subscribe" widget because of the "only 5 feeds for free" limitation. And of course, technology has moved on: By adding my Google+ page to your circles, you should be able to follow the blog.
If you have a better alternative, please let me know.

PostgreSQL 9.2 is out: It's faster

noreply@blogger.com (Steffen Macke) — Mon, 10 Sep 2012 15:38:00 +0000

A new version of the open source PostgreSQL relational database management system has been released. The performance was improved once more (e.g. via index-only operations). Detailed information can be found in the release notes.

Improved Dia shape export: Draw your connection points

noreply@blogger.com (Steffen Macke) — Thu, 23 Aug 2012 20:55:00 +0000

I've pushed a commit to Dia master that improves Dia's shape design capabilities. Instead of adding plenty of connection points to each and every element of the drawing, you can place the connection points exactly where you want them. It's also possible to "draw" the main connection point (That wasn't possible before). The main connection point is the connection point that is taken if a line is moved over a shape, but none of the connection points is close enough to snap.
Let's have a look at how the new shape design process looks like: You start by drawing/importing your shapes in Dia (just like you've done before). But instead of accepting the default of "place connection points everywhere you can think of", you open the new "Shape Design" sheet and use its connection point shapes (the black x shape in the toolbox) to define the connection point locations in your new shape. Don't forget to place exactly one main connection point - it's the red x shape.
As an example, I've drawn a very simple floor plan chair symbol below with two connection points (I've changed their color to orange) and one main connection point.

Once you're done with the shape design and connection point placement, save your diagram (use it as a master when you want to change your shape later on) and then select File->Export from the menu to export it in the Dia shape format.

The following picture shows two shapes created from the above drawing. The left one used the three connection point shapes (main connection point is not shown), the right one illustrates the old "many connections" approach. Many shape designer have complained that the number of automatically placed connection points was just too much and that it was a lot of effort to clean them up manually. The new shape design approach avoids this. In case you prefer the old approach, simply don't place any connection point shapes in your drawing before exporting and your shape export will be done as before.

In case you're new to Dia shape creation, there's a short tutorial that you may want to follow.
If you can't wait until Dia 0.98 is released, you'll have to compile Dia yourself if you would like to testdrive this new feature. You could use the Dia Development VM in that case.

For those of you that are into direct editing of the Dia shape XML code, here's the difference:

Connections exported by Dia 0.97.2

 <connections>

    <point x="0" y="0"/>

    <point x="5" y="5"/>

    <point x="0" y="5"/>

    <point x="0" y="2.5"/>

    <point x="5" y="0"/>

    <point x="5" y="2.5"/>

    <point x="2.5" y="5"/>

    <point x="2.5" y="0"/>

    <point x="5" y="0"/>

    <point x="6" y="5"/>

    <point x="5" y="5"/>

    <point x="5" y="2.5"/>

    <point x="6" y="0"/>

    <point x="6" y="2.5"/>

    <point x="5.5" y="5"/>

    <point x="5.5" y="0"/>

  </connections>

Connections exported from new code

GTK DBF Editor 1.0.4 for Mac OS X 10.8 Mountain Lion

noreply@blogger.com (Steffen Macke) — Wed, 22 Aug 2012 20:02:00 +0000

An updated GTK DBF Editor App is available for Mac OS X 10.8 Mountation Lion. The App now has a valid developer signature and does not require X11 any more. And the download is almost 25% smaller. Grab your GTK DBF Editor App from sdteffen.de/gtkdbfeditor.

Did the drought contribute to the Syrian uprising?

noreply@blogger.com (Steffen Macke) — Fri, 17 Aug 2012 18:58:00 +0000

An article in the Bulletin of the Atomic Scientists investigates if the recent droughts in Syria have contributed to the events that lead to the uprising. I think it's an interesting read, but focuses too much on agriculture and climate change.
The water supply problems don't stop once the rural population is driven to the so called informal settlements clustering around the large cities. Urbanization in conjunction with a high population growth rate put enormous stress on the water supply infrastructure. Selective negligence of the stressed infrastructure can be used when trying to enforce urban planning schemes - another factor that's driving a society apart.
It's often difficult to tell if the lack of water is the root of the problem or just a symptom of poverty. And of course, an ample supply of water wouldn't stop the civil war in Syria.

Software updates: PostgreSQL 9.1.5, PHP 5.4.6

noreply@blogger.com (Steffen Macke) — Fri, 17 Aug 2012 18:27:00 +0000

The PostgreSQL and PHP projects have released updates.

PostgreSQL 9.1.5 This fixes some security issues - better update that database with the elephant...
PHP 5.4.6 - More than 20 bug fixes.

EPANET App for Mac OS X 10.8 Mountain Lion

noreply@blogger.com (Steffen Macke) — Thu, 16 Aug 2012 21:12:00 +0000

An updated EPANET App for Mac OS X is available from epanet.de (Version 2.00.12.1). The bundle now includes a signed Wine version allowing to pass the Mac OS X 10.8 Gatekeeper security check. The bundle also includes an X Server - no separate X Server installation is required any more. Thanks to the Wineskin team for making this possible.
EPANET is an open source hydraulic analysis software that can be used to analyse water supply networks.

64-bit Windows version of EPANET-MSX

noreply@blogger.com (Steffen Macke) — Mon, 13 Aug 2012 16:15:00 +0000

A 64-bit version of EPANET-MSX for Windows (EXE and DLL) is now available from epanet.de/epanet-msx. The instructions how to build are also available. EPANET-MSX is a multi-species extension for EPANET.

Updated Dia DMG for Mac OS X 10.8 Mountain Lion

noreply@blogger.com (Steffen Macke) — Sun, 12 Aug 2012 08:52:00 +0000

The new Mac OS X 10.8 Mountain Lion caused some problems with the previous Dia DMG package. Depending on your security settings Mountain Lion's new Gatekeeper security feature might check for a signature from a registered Mac Developer and prevent Dia from running. To overcome this, I've joined the Mac Developer Program and was able to sign Dia.app for Mac OS X.

There's an annual fee for the Mac Developer Program, it would be great if some more people would donate in order to cover this cost. Remember that Dia is free software.

As Mountain Lion removed X11 from the default installation, I added an X11 check to the app that will tell you about the problem and automatically take you to the XQuartz website, allowing you to download and install XQuartz.

The updated DMG (0.97.2-5) is available from
http://dia-installer.de/

download/macosx.html

Thanks to those who brought the Mountain Lion problems to my attention and those who've donated already!

Dia is not the only Mac software I've published. Watch our for some more updates over the coming days.

The world's water balance: groundwater stress in 800 aquifers

noreply@blogger.com (Steffen Macke) — Thu, 09 Aug 2012 18:50:00 +0000

Slashdot brought my attention to a story published in Nature: "Demand for water outstrips supply". Yes supply vs. demand once more. If you've ever looked at the problems compiling such water balances on a national level of a small country, you'll be aware of the problems to do this on a global level.