sdteffen's blog

GHydraulics 2.1.8: EPANET simulation fixes and QGIS 2.2.0 support

noreply@blogger.com (Anonymous) — Fri, 04 Apr 2014 16:34:00 +0000

A new GHydraulics version (2.1.8) is available from the QGIS Plugin repository. The sample projects have been upgraded to the current QGIS version 2.2 in order to prevent nagging upgrade dialogs. And once again a couple of bug fixes have been applied to the "Run EPANET simulation" functionality. The different platforms (Windows, OS X and Linux) along with different deployment methods (plugin manager vs. git) complicate the testing process. That's why your input is important. The good news is that more and more users report GHydraulics bugs. If you would like to report a bug, the GHydraulics Bug Tracker would be the perfect place. But if you don't know how to operate it, any other means of communication (email, etc.) is also fine. Thanks to all those who have reported bugs!
In case you've never successfully used "Run EPANET simulation", please give it a try and get back to me if it doesn't work.

One tip if you're having problems to get your model to run from within GHydraulics: Instead of using "Run EPANET simulation", keep writing INP files, fix them in EPANET, repeat those fixes in QGIS and only use "Run EPANET simulation" after "Write EPANET INP file" created a working EPANET model for you. The EPANET UI is (still) easier to operate for beginners than what QGIS/GHydraulics are offering.

GHydraulics is an open source QGIS plugin that allows to create and run 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. Learn more on the GHydraulics home page.

EU-DEM: Digital Surface Model with 25m resolution for Europe, the Mediterranean and the Middle East

noreply@blogger.com (Anonymous) — Wed, 12 Feb 2014 18:41:00 +0000

Markus Neteler introduces the EU-DEM Digital Surface Model with 25m resolution covering Europe, the Mediterranean Sea and parts of the Middle East in a blog post.
Digital Elevation Model (DEM), Digital Surface Model (DSM) and Digital Terrain Model (DTM) are often used synonymously. They are often used in GIS data to extract elevation information or visualize terrains.

Inptools 2.0.12.1: Explorer integration for inp2shp

noreply@blogger.com (Anonymous) — Tue, 28 Jan 2014 14:52:00 +0000

A new Inptools version has been released.

Version 2.0.12.1 integrates shp2inp in the Windows Explorer context menu. You can now generate Shapefiles with by right-clicking on the INP file in Explorer. The generated Shapefiles can be opened in GIS software like QGIS. In addition, several inp2shp bugs were fixed, some sample files are included in the installation and the first three digits of the version number reflect the version of the included EPANET version.
Inptools bundles the current EPANET version for Windows 8.1, 8 and 7 together with documentation and additional tools to process EPANET INP files. It's a regular topic in this blog (Inptools label).

Marc Andreessen: "Why Bitcoin Matters"

noreply@blogger.com (Anonymous) — Thu, 23 Jan 2014 11:53:00 +0000

Marc Andreessen, one of the guys that created the web browser as we know it today, shares his thoughts on Bitcoin: "Why Bitcoin Matters"
I think that's the best summary of Bitcoin's potential I've seen so far.

Improved Dia Shape Search available online

noreply@blogger.com (Anonymous) — Wed, 22 Jan 2014 19:56:00 +0000

New and improved Dia Shape Search is available on http://dia-installer.de/shapes/search.html The search results now contain the toolbox icons, which makes it much easier to judge if a listed object is really what you're looking for. The search should be much faster now, occurring as you type ahead (you don't have to click the search button any more). And searches are performed locally in the browser, your search terms are not send to any server. Compared to the old search, the data is more up to date with all objects from the Dia distribution and the Dia Shape Repository, including updated translations.
Dia is a popular open source diagramming application.

QGIS Elevation Plugin 0.4.0 does not require a browser any more

noreply@blogger.com (Anonymous) — Wed, 15 Jan 2014 14:58:00 +0000

A new version of the QGIS Elevation Plugin is available from the QGIS 2.0 Plugin Repository. The Google elevation maps are now displayed directly in QGIS (see screenshot below).

GHydraulics 2.1.6: Run EPANET simulations in QGIS

noreply@blogger.com (Anonymous) — Wed, 15 Jan 2014 11:53:00 +0000

GHydraulics now allows to run EPANET from within QGIS (on Windows, Mac OS X and Linux). Previous versions were able to create EPANET models, but you had to run the simulation in EPANET and import the results yourself. To use the new functionality, simply select Plugins->GHydraulics->Run EPANET simulation from the menu. Once the EPANET run has completed a dialog with the EPANET output and report is presented. If the analysis suits you, you can choose a time step and load the results into your themes.

Several GHydraulics functions now use the QGIS undo history. You may want to see the Undo/Redo toolbar to get the full benefit from this feature. You could use it e.g. to quickly switch between result steps, once they have been loaded into QGIS.
The "Calculate economic diameters" function that was always present in GHydraulics, but never integrated with the Settings dialog, will now operate on all configured pipe layers as long as you're using liters/second as flow units.
Several bugs have been fixed and two new example projects have been added.
The plugin ships 5 EPANET binaries to support the 32- and 64-bit versions of Windows, Mac OS X and Linux and has been tested successfully on those platforms. Yet there might be configuration or other platforms that do not work - in this case, please contact me in order to fix that problem.
GHydraulics is an open source QGIS plugin that allows to create and run 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.

TIP4COMMIT: 293 commits to pay out 90% of a tip

noreply@blogger.com (Anonymous) — Tue, 31 Dec 2013 13:27:00 +0000

Following up on the previous "Bitcoins for open source developers: BitHub and TIP4COMMIT" post, I had a closer look at TIP4COMMIT. TIP4COMMIT takes a 5% "fee" and pays out the remaining 95% of a tip. I think that's fair. And there's a payment threshold of 0.001 BTC per user (currently around 0.8 USD). That also makes sense to me. What I think is problematic is the fixed payout of 1% of the available amount. In a scenario where there's only one tip, it takes almost 300 commits to pay out 90% of the original tip amount. 300 commits is a lot for small projects with just a few contributors. The good old "commit early, commit often" is true once more. It would be great if TIP4COMMIT would either allow to change that fixed percentage for a given project or analyze the per-project commit frequency and use that to ensure a payout over a reasonable amount of time (e.g. half a year). Because the whole thing is named "TIP4COMMIT", I was unsure if the committer or author will receive the Bitcoins. I was happy to learn that it's the author. And it just takes a couple of minutes after the commit is pushed to GitHub until the author receives the TIP4COMMIT email - including an option to opt-out of future email notifications.

Bitcoins for open source developers: BitHub and TIP4COMMIT

noreply@blogger.com (Anonymous) — Wed, 18 Dec 2013 19:03:00 +0000

Bitcoin, the disruptive open source currency, should be a natural choice to reward developers contributing to open source projects because of the low transaction cost - even for small transactions. The list of open source projects that had their donations frozen by Paypal is long. In the past, I've created bitcoin addresses to receive donations for dia-installer.de ( 1NxRxasGJTzUifTbcvbxoReWC1s48sP9Nr ) which worked as you can see e.g. on block explorer.com and epanet.de ( 1QFKurFsQSxyk6QN6wC9Rt4coGeXuvCwfu ) which did not yield any donations yet - but I've also not received donations to epanet.de on any other channel. Where people contribute to my page, i try to convince them to create a Flattr account and add their Flattr buttons to the respective pages. Of course it would be also possible to add Bitcoin addresses instead or in addition to the Flattr buttons. But most of the contributors don't even want to take the time to sign up with Flattr. Installing, maintaining and securing a bit coin wallet is in my eyes a much bigger effort. But the Bitcoin hype is of course much bigger than Flattr (according to Google Trends).
Today I've encountered two projects that take Bitcoin donations to open source projects to the next level, because they try to spread donations among all committers. BitHub is an open source server software that you can use to spread money from a Bitcoin wallet to all contributors. The repositories have to reside on Github and you'll need Github and Coinbase accounts for the server. Together with software installation, configuration and maintenance, this might be attractive to larger projects with some kind of commercial background.
The second approach is easier to use: TIP4COMMIT allows to donate to all committers in Github projects (of course, you have to choose the project). Everyone can add new projects and TIP4COMMIT will automatically generate a Bitcoin donation address. Here's an example: sdteffen/epanet.js In short: Trying to convince contributors to sign up to Flattr is superfluous with TIP4COMMIT, everyone will get their share automatically.
In case you would like to send or receive donations for a Git repository that is not hosted on github: Just create a clone on github - because BitHub and TIP4COMMIT use the committer data, your clone will work just as the original repository.
Now I'm waiting for the first donation to see if it works...
Update: Some more information on TIP4COMMIT

SWMM App for Mac OS X

noreply@blogger.com (Anonymous) — Tue, 17 Dec 2013 15:00:00 +0000

EPA SWMM 5.0.022 packaged for OS X is now available on epanet.de/swmm. The app was created using Wineskin and has been tested on OS X 10.8 and 10.9.
Quote from Wikipedia: "The United States Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) is a dynamic rainfall-runoff-subsurface runoff simulation model used for single-event to long-term (continuous) simulation of the surface/subsurface hydrology quantity and quality from primarily urban/suburban areas". SWMM is open source software.

epanet.js 2.0.12.3: Update for current emcc version, improved compilation instructions

noreply@blogger.com (Anonymous) — Fri, 13 Dec 2013 14:30:00 +0000

epanet.js has been updated to work with the current emcc version. In addition, the compilation instructions for Windows users have been improved.

The epanet.js app is a JavaScript version of EPANET that requires no installation. The app runs in the browser, making it available on personal computers as well as tablets and mobile phones. There's no model data send to the server, the simulation takes place in the browser.

QGIS Elevation Plugin 0.3.0 supports QGIS 2.0

noreply@blogger.com (Anonymous) — Wed, 11 Dec 2013 13:48:00 +0000

A new version of the QGIS Elevation Plugin is available from the QGIS Plugin repository - QGIS 2.0 is now supported. The open source plugin obtains point elevations using the Google Maps Elevation Service and displays them in Google Maps.

HVAC shapes for Dia

noreply@blogger.com (Anonymous) — Tue, 10 Dec 2013 13:02:00 +0000

HVAC (heating, ventilation and air conditioning) shapes for Dia have been created by Joshua A. Shaw. The shapes are freely available from dia-installer.de/shapes/HVAC and via diashapes. Thanks, Joshua!

Use EPANET from Haskell

noreply@blogger.com (Anonymous) — Sun, 08 Dec 2013 18:32:00 +0000

A Haskell version of the EPANET toolkit is available. The epanet-haskell sources are available on Github. This is the 10th programming language supported by the EPANET toolkit. The code was developed and tested using the Glasgow Haskell Compiler (ghc), the Gnu Compiler Collection (gcc) and GNU make on Ubuntu Linux.

Win a free copy of "Learning QGIS 2.0"

noreply@blogger.com (Anonymous) — Sun, 08 Dec 2013 10:15:00 +0000

Head over to Anita Graser's blog in order to win a copy of her book "Learning QGIS 2.0". The contest closes December 12, 2013.

EPANET-MATLAB Class

noreply@blogger.com (Anonymous) — Mon, 28 Oct 2013 08:21:00 +0000

Marios Kyriakou and Demetrios Eliades have released an EPANET-Matlab-Class, providing another option to use EPANET from MATLAB. epanet.de/developer/matlab.html was updated with a link to the github repository. The code is released under the terms of the EUPL.

GHydraulics 2.1.4: On-the-fly reprojection and QGIS 2.0 support

noreply@blogger.com (Anonymous) — Sun, 27 Oct 2013 16:22:00 +0000

GHydraulics now supports the QGIS 2.0 API and can be installed through the QGIS 2.0 Plugin Manager (as it was with QGIS 1.8). The new version 2.1.4 also adds on-the-fly coordinate reprojection support. If you've selected a coordinate reference system (CRS) in the project properties, all coordinates written to the INP file will be reprojected to match that CRS. This should also fix some problems where coordinates in INP files did not match backdrop map coordinates.

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.

bedup dedup: Data deduplication using Btrfs and bedup

noreply@blogger.com (Anonymous) — Sat, 19 Oct 2013 18:41:00 +0000

These days backup CDs from the 90's are reaching their end of life. The good news is that modern hard drives, USB sticks and memory cards provide enough storage capacity to consolidate hundreds of CDs on a single media. When you just copy all CD contents next to each other, it's still a pity that disk space is wasted when there are multiple copies of the same file on different CDs (or on the same CD). In case your data files are "atomic" without references to their neighbors, you might simply search all duplicates and delete them. But when you're dealing with source code using include files or typical HTML files, this simple approach will inevitably corrupt some of your structures.
This is where data deduplication steps in: Instead of simply deleting the duplicates, they're replaced with references to the duplicate content (cheap copies), saving disk space but keeping all references in place. While deduplication software has been around for a while, Linux's new Btrfs file system with its "copy on write" paradigm provides a particular elegant deduplication approach: The file system provides everything to store references to the duplicate files. It'll also remove those references when necessary (one of the files is changed).
Bedup is a tool that actually performs the deduplication as a batch job - because Btrfs is not (yet) able to identify and track duplicates. Once you have a Btrfs file system mounted and bedup installed, you'll be able to deduplicate by running
sudo bedup dedup
Bedup just looks at the contents of your file. In case one copy of the same file is named long_and_descriptive_file.html and another one LONG_AND.HTM, bedup will still deduplicate them.
In case you would like to deduplicate files smaller than 8 MB, you should change the "size cutoff" by passing the --size-cutoff parameter to bedup dedup (in bytes). Running bedup dedup --help will display the deduplication documention.
Bedup stores metadata like file fingerprints in a sqlite database. The default database file location is ~/.local/share/bedup/db.sqlite.
Of course the 90's CD archive consolidation is just one example where deduplication comes in handy. Today's cloud technology invites you to create many, many copies of your files.
Bedup dedup - sounds a little like Bob Marley's "Get up, stand up".

Sankey diagrams for EPANET models

noreply@blogger.com (Anonymous) — Mon, 30 Sep 2013 13:34:00 +0000

A new epanet.js version (2.0.12.2) allows to create Sankey diagrams from your EPANET analysis results. In Sankey diagrams the link width is proportional to e.g. the flow through that link. The diagrams are named after after Irish Captain Matthew Henry Phineas Riall Sankey. To use the Sankey diagram in epanet.js, simply choose "Sankey" in the View menu at the top of the window. Note that you can vertically rearrange the nodes to make your diagrams look better. Hovering the mouse over a link will provide you with a tooltip. Use the link dropdown under analysis to switch between flow, velocity and headloss data.

epanet.js version 2.0.12.1 released

noreply@blogger.com (Anonymous) — Sun, 25 Aug 2013 21:18:00 +0000

An updated and extended version of epanet.js, the app that allows to analyze EPANET INP files in your browser has been released. The new version adds a simple network map display, result visualization and the possibility to load and save INP files from the local file system (if supported by your browser).
Of course, a GIS interface is still missing, but the current state should be sufficient for the average user to give it a test drive.

QGIS Elevation Plugin version 0.2.0

noreply@blogger.com (Anonymous) — Tue, 20 Aug 2013 11:00:00 +0000

An updated version of the QGIS Elevation Plugin is available from the QGIS Official Repository 2. The new release just fixes a couple of issues, no new features have been added. The source code is now available on Github: github.com/sdteffen/qgis-elevation

Extreme spriting

noreply@blogger.com (Anonymous) — Fri, 16 Aug 2013 07:24:00 +0000

CSS Spriting is a web design technique to optimize page load times by reducing the number of requests to the web server. Instead of loading many individual images, one large image containing all images is loaded and split into individual pieces by the browser.
The simplest possible sprite implementation is to place all images in one row next to each other. That's what I did initially for the shape icons on dia-installer.de. Everything was fine, but with more and more icons added the sprite image grew to something like 27,000 by 22 pixels. In Firefox and Chrome everything still looked fine, but Internet Explorer refused to render the sprite and displayed black boxes instead (see below). The Safari rendering was even funnier.
The solution was to limit the sprite width to 2,200 pixels and to place several rows of sprites in it. Now Internet Explorer and Safari are back on track. It's still strange, because the number of pixels in the sprite image (it's size) is larger in the new version.

Get started with balloon mapping

noreply@blogger.com (Anonymous) — Mon, 12 Aug 2013 08:10:00 +0000

The Public Laboratory of Open Technology and Science (PLOTS) is offering a Balloon Mapping Kit that can be used with open source software like MapKnitter to create your own maps. Happy ballooning!

GHydraulics 2.1.2: Usability improvements, sample project and backdrop map

noreply@blogger.com (Anonymous) — Sun, 11 Aug 2013 18:04:00 +0000

An option to write backdrop maps has been added to the GHydraulics 2.1.2 settings. Usability and robustness have been improved in several places. There are new menu items to create new GHydraulics projects from scratch and open a sample project (Darcy-Weisbach headloss formula, cubic meters per day). The pipe length calcuation was improved, if necessary the length is calculated through an UTM reprojection. As usual, the updated plugin is available from the "QGIS Official Repository".
If you're wandering how you can install GHydraulics in QGIS, head over to epanet.de/ghydraulics to find a short video.

New languages for EPANET: Russian and FORTRAN

noreply@blogger.com (Anonymous) — Tue, 06 Aug 2013 17:01:00 +0000

A Russian version of EPANET and the manual are available from www.epanet.com.ua/books.

And for those who are interested in using the EPANET toolkit from the FORTRAN programming language: epanet.de/developer/fortran.html