Hortonmachine 0.10.0 released - get a grip on your basins size

It sure is a while that I don't post about the Hortonmachine. While we work a lot on it and with it, it always kind of stays in background. Well today we decided to make a new release due to some tools that will be used in production environments. And I think one is definitely worth to mention.

Some of you might have used the netnumbering module to extract subbasins on a network. The module also accepts monitoring points to allow splitting the basin in fixed points. 

For a watershed like this:

The result is something like:

Now, some models, as for example Riccardo Rigon's Geoframe, need a bit more control over the basin's size. This is why, on Riccardo's request, we added the possibility to set a desired output basins size and  buffer threshold, to handle some degree of flexibility.

It has been quite some fun and recursive exercise to aggregate in the best possible way basins that are too small. We added plantuml mindmap outputs to be able to better check the way the hierarchy is getting merged. This has been really helpful, in particular to check large basins and also to check on monitoring point positions, which is where basins are meant to keep a fixed border.

 Here the mindmap of the above basin, with references to areas and fixed basins:

and finally the aggregated basins mindmap assuming a desired basin size of 100000 cells (10*10 meters here) and a 20% of threshold:

and the resulting subbasins map:

The result is quite nifty, given the fact that the only basins that do not obey to the 20% buffer are either basins that are fixed and at the very top (so they can't be merged with anyone) or basin 6 which is "blocked" between 2 fixed basins, so same as before, no way to enlarge it by aggregation.

Well, you can find a release containing the tools at the usual release download site of the Hortonmachine here.

Enjoy! We surely did :-)

 

How to supply network to a linux box through a macosx through ethernet

This is for sure no GIS and no java, but it can be usefull to others, so here I go with it.

The problem: supply internet connection to a colleagues computer running linux from my macosx box. I have a broadband connection given me trough an USB-modem.

This was pretty easy, at some point I'll have to get that also throught airport connection, not sure about the security issues tho.

ON MY MAC:
1) the first thing to do is to activate leopard's (my current macosx operating system) internet connection sharing. This is easy. Go under preferences->sharing and just activate it. Select in the combobox the active internet connection and from the list below the way you want to share the connection with the linux box.

In my case I have an ethernet crossed cable for connections between two pcs, so I choose Ethernet.

2) check out the connection properties. In the network settings I see that my modem is connected with the IP address: 10.98.0.76


BTW I need to know the gateway of that all, i.e. the connection address to the outer world. This can be achieved through the supplied connection software of my modem, though I'm sure there are a lot of other ways. There are also google widgets to trace the connection.


As you can see the connection goes to 10.64.64.64. Now I have to set up properly the ethernet connection, since the connection will not supply dhcp and we need to be all on the same network.


So i simply set up the ethernet connection with a static address of one more than the modem ip address and the proper netmask. The router is the link to the outer world and that's all.

No wait, we need the DNS, which we can retrieve in the advanced settings of the modem connection, in my case:
62.13.171.4
62.13.171.5

Alright, now I'm ready to jump to my linux box:

ON MY LINUX BOX (KUBUNTU FEISTY):

1) Edit the network settings file: /etc/network/interfaces
and put the following into it:

auto lo
iface lo inet loopback

mapping hotplug
script grep

iface eth0 inet static
address 10.98.0.78
netmask 255.255.0.0
gateway 10.98.0.77


2) Edit the DNS file: /etc/resolv.conf

nameserver 62.13.171.4
nameserver 62.13.171.5


And start your network:
sudo ifup eth0


This should work at that point! Enjoy!

---

UPDATE: I right notice that the static IP thing could be misleading as I put it.

Instead of 10.98.0.78 on your linux box and 10.98.0.77 on your macosx system you could use more usual numbers for the internal networks, as for example 192.168.1.123 and 192.168.1.124.