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Tuesday, February 28, 2012

More Mac Mini wrestling...

Okay, so I didn't quite give up when I said I did.  More notes on this install.

1) Downloaded Xcode 4.3 and then tried a fink install but it whined about not finding a c compiler.  After some googling, I found out that you need to download the command line tools from the "Downloads" tab within Xcode's preferences.  This is pretty complicated for us "hello_world.c" folks.

2) After doing that, trying a fink installation again.  Jumped into the fink install directory and did "./bootstrap" and ran with all the defaults.  It attempted to make a new /sw2 directory so I killed the job and did 'sudo mv /sw /sw_fail' to get that out of the way then launched the bootstrap script again.

After a few minutes:

3) After fink installed, I typed:


This setup the fink path by creating a .profile file in my ~ (one wasn't there already, not sure what it would have done if one was).

Then typed:

    fink selfupdate-rsync
    fink index -f

That's it and probably a good spot to stop for tonight...

Wrestling with a Mac Mini

So, I got a Mac Mini for home.  Mostly for hooking up to the TV, watching netflix, looking at family pictures and listening to music.  I thought I'd set it up to build all the software that I've been working with (see post from April 2010).  Here are some notes on what I did...

1) From my first dealings with building OMG software on a MAC (April, 2010), I installed Xcode.  It seems the only way to download this now is to do it through the app store, and they want my credit card information when it's supposed to be a free download.  This made me, I'm trying out an alternative approach:

I downloaded the following:

GCC-10.7-v2.pkg — GCC Installer for OSX 10.7+, Version 2 (includes X11 headers, bugfixes). 

The lovely .pkg file unpacked into a wizard that promptly installed without issue.

2) Now for fink:

It warns that Xcode is required...let's see about that.  I followed the instructions on the fink install docs page, jumped onto the command line and dove into the unpacked tarball directory.  Typed "./bootstrap" and found that it wanted the Java Runtime Environment installed...somehow the command line install script fired off a software update to do this.  Magic.

Okay, running "./bootstrap" again and it's asking me some questions.  I just went with all the defaults and off it goes, curl'ing away.  It died for want of an Xcode installation.  I am, however, still angry.  Time to dig out the old .dmg from when I installed Xcode on my work laptop almost 2 years ago.  How much could gcc have changed since then???

3) Trying to install Xcode 3.2.1 from a nearly two year old .dmg.  The 'gcc' install said it was okay to install Xcode right on top of it, so I didn't do anything to undo step (1).  Ran off the .dmg and it installed without whining at all.

4) Now for fink, part II.  Back on the console, "./bootstrap" again and I get:

ERROR:  This version of fink needs at least Xcode 4.1 on this OS X version.

5) I am still angry, so I'm willing to try an older version of fink.  Luckily, I kept the tarball for the fink-0.29.10 install I did on my work laptop.  At this point, I just want to see if I can do this without giving the App Store my credit card as a matter of principle...and barf, it's not happy:

Argument "10.7 does not match the expected value of . Please run `..." isn't numeric in exit at /Users/amy/Documents/installs/build/fink-0.29.10/perlmod/Fink/ line 1381.

6) I'm tired and I give up.  Let's get out the credit card just to let the App Store let me download some free software.  What a bunch of A-holes.

That's about enough for tonight.  I know myself well enough to stop now: I might hurt some files.

Wednesday, February 15, 2012

Global RTOFS: SVP Weather Map

Now that I'm comfortable with the Global RTOFS grid, I decided to churn out what I call an SVP Weather Map.  This is a map that characterizes the impact of oceanographic spatial variability on multibeam echo sounding uncertainty.  For seabed mapping applications, we're usually trying to minimize the effect of this source of uncertainty.  Since its effect is usually felt most strongly on the outer most beams of the echo sounder, the analysis is run for a beam angle of 60 degrees (for a total angular sector of 120 degrees).  I'm hoping that products like this can be used to provide guidance to mappers in pre-cruise planning (helping to choose appropriate sound speed sampling instrumentation) and during acquisition (to help guide sampling intervals and locations) and perhaps in post-processing.

Here's a brief description of how it's made:  Each grid cell in RTOFS is used to construct a sound speed profile, this is then compared to its eight immediate neighbours in the grid.  The comparison is done on ray traced pathways derived from the nine sound speed profiles using a common launch angle (in this case, 30 degrees down from the horizontal).  The dispersion of the ray path solutions at their terminal locations is used to quantify the impact of the spatial variability in water mass properties.  Ray paths are resampled to a common time increment and the largest travel-time for which there are nine solutions provides us with a point cloud in the two-dimensional depth/distance ray tracing plane.  The standard deviation in the vertical dimension is computed for the point cloud and reported along with the geographic position of the grid node.  Rinse and repeat for all grid nodes and then make a map.  Here's a global map based on the RTOFS grid for Feb. 13, 2012.

We can zoom in to the Gulf Stream region and have a closer look.

Since the RTOFS grids include a 6 day forecast, we can make an animation of the Gulf Stream area (each frame is 1 day).

We can zoom in even further and see what the NOAA Ship Okeanos Explorer is going to be dealing with on their shake down cruise over the next two weeks (ship track is dashed black line).