Archive for February, 2007
National Geographic announces that there might be water on mars, because some vehicle found geologic structures that might have been formed by water.
This is not a new story, but it is a main article in the online edition of “Der Spiegel” today: The fact that pharmaceuticals, such as cough sirups, antibiotics, or pain killers are not totally taken up by the human body. The part that is not being taken up, usually ends at a wastewater treatment plant, and more often than usually can’t get treated there. So all these medical substances get released into the environment.
The article talks about the research group around Andrew Singer at the University of Oxford. He is a mathematical modeler, and wanted to know what would happen to “Tamiflu” – concentrations in british rivers. Tamiflu is supposed to treat people during an influence pandemic, which is when millions of Britons would use it.
Singer’s group showed that under such epidemic conditions, significant concentrations of Tamiflu would exist in rivers. There, lots (unimaginable many) of other life-forms would get into contact with Tamiflu, and the consequences can’t be imagined. As one consequence however it seems pretty certain that a few organisms that are believed to play a key role in transmitting influenza (the waterfowl) might develop a resistance against Tamiflu, and hence magnify the epidemic problem.
Worldmapper.org has a few interesting maps. These maps show the size of a country relative to a quantity per country. Such a quantity can be “people without access to clean water” (see below, from “Der Spiegel”). You can try different things by searching for the term “water” on worldmapper.org.
At work, we have a lot of fortran codes. And some people still develop in fortran. Don’t ask me why… I totally love the python/TextMate combo… well, but I needed to wrap my head around the whole fortran issue. Mostly, people here use Compaq Visual Fortran on Windows XP machines. That is a decent setup. But I wanted to try some things on my mac. So I looked into options. Note: I am still a very user oriented person… I still haven’t gotten very deep into the computer systems…
I got a little scared, because I thought I have to build gcc somehow myself, and I didn’t know what and how, but then I found the guys at macresearch.org. With a very straight forward 4-item cookbook-approach, I had xcode setup so I can edit, debug, and let fortran programs run. Here we go:
- Make sure you’ve got xcode (Apple Developer Tools) installed.
- Download an installation package from here. This package will install gfortran and the necessary xcode plugins.
- Follow these instructions. If you do this you will end up with an xcode project. In this xcode project a c-file will call a fortran file.
- If you want pure fortran, use these instructions.
With this setup I can copy my .f90 files from the MS-Compaq compiler to my mac, read them in xcode, and they compile just fine! ATTENTION: copy the entire .f90 files, no copy and pasting, especially not through email! That destroys the file-setup.
If somebody knows anything about how to couple TextMate to this setup — let me know!
[Update 20070210]: Re: File Endings
The file ending of the fortran file is important as to how xcode interprets the file for compilation. *.f leads to fixed form fortran77 type. *.f90 leads to free from fortran95 type. The file ending should be changed in xcode by right clicking on the file in the “source” area.
[Update 20070210_2]: Re: location of input files
Say the xcode project you’re working on is called “FileIO”, and is located at
Then an input file opened through the command
OPEN (UNIT = 3, FILE = filename, STATUS = 'OLD', ACTION = 'READ', &
IOSTAT = status)
needs to be stored in
Otherwise an IOSTAT = 2 error occurs.
[Update 20070211]: Re: debugging “jstingley’s” points on macresearch regarding debugging are very important
- In the project window, Groups & Files pane, select your target (open the Targets group) and then click the Info button in the toolbar.
- In the Target “myfprog” Info window select the Build tab.
- Select Configuration: Debug (pop-up).
- Select Collection: Language (pop-up under GCC Fortran source compiler).
- There’s only one setting: OTHER_FORTRANFLAGS.
- To the right in the Value column, double click and enter “-g” (w/o the quotes) and “return”.
Close the Info window, rebuild (w/ Debug as the Active Build Configuration) and then run the debugger. You should now see the program pause at your breakpoints and the current module’s variables displayed.
Make sure you select the Target Info and make these settings. It doesn’t seem to work if Project Info is selected and the -g option is added there.
Der Spiegel, the Globe and Mail, and pretty much every other media is full of stories on the latest UNO report on climate change these days. However, as of today only a miniscule part of the entire planned publication is available today, the summary for policy makers (SPM), a 21 page long summary of the “Working Group I”. In total there are three working groups: 1) The Physical Science Basis, 2) Impacts, Adaption and Vulnerability, and 3) Mitigation of Climate Change
In this first part of the four volume long “Climate Change 2007” report describes progress in understanding of the human and natural drivers of climate change, observed climate change, climate processes and attribution, and estimates of projected future climate change. This first document pretty much says we know more since the last report, and we know with more certainty that human activity leads to a warmer atmosphere, higher sea levels, and more severe weather events. See the “Real Climate” Blog for a more in depth discussion of the SPM
Here is an argument, that I stole from Taha Ouarda relating to climate change. It illustrates the point with a nice example. The example has to do with hockey, hence I like it:
Last year, the [Montreal] Canadians got a new coach. After the new coach has been working with the team for a while, results got better, and now the team as a whole is playing better than before. Without a doubt the change of the coach lead to a different situation, that is a better hockey team. Then you might ask: Was Saku Koivu’s goal last night a direct result of that coach change?
The answer is no. Firstly, Saku Koivu is a pretty wicked hockey player, and he has always scored lots and nice goals. Secondly, it is not possible to trace one event to one change. Similarly, it is not possible to say if the current winter in Germany that is warmer than average is the direct result of high CO2 concentrations in the atmosphere. But we know, that higher CO2 concentrations in the atmosphere lead to warmer air.
Speaking of hockey, the picture in this blog entry shows the same “hockey stick curve” as the one Al Gore used in his movie “An Inconvenient Truth“.
Well, and then there’s these guys…
Water is cool!
These guys make a water bottle that tells you when you’re thirsty. Oh wait… you know when you’re thirsty…