Wednesday, March 21, 2012

ENVI/IDL and ArcGIS/Python integration

I occasionally answer questions on ENVI/IDL and ArcGIS/Python integration.

ENVI functions are available as "tools" through the ArcGIS GUI toolbox:

"With ENVI 4.8, ENVI’s scientifically proven image analysis capabilities will be available as discrete tools in the ArcGIS toolbox and accessible directly from ArcGIS desktop and server environments. Upon installation of ENVI products, a selection of powerful image processing and analysis tools will be available within ArcGIS."

A list of those tools is here (in the context of licensing, but just ignore that): 

IDL can also be accessed for extension of ENVI/IDL functionality:

"developing customized ENVI tools can be done using simple IDL scripting and wrappers that facilitate the integration of ENVI tools with the ArcGIS platform."

Here's a whitepaper:

Thursday, March 8, 2012

Configuring svn on Apache

I followed this page to install/configure svn on my server ... it's written for Windows-based Apache install, so I've summarized and transcribed the following platform-anostic (and maybe overly general) steps:

  1. make sure dav_module, dav_svn_module, and authz_svn_module are installed on Apache (assuming you're using webdav to do svn)
  2. create an (arbitrarily named/located) svn config file (maybe called subversion.conf) and include in httpd.conf
  3. create an (arbitrarily named/located) auth file (maybe called svn-auth-file) with the htpasswd binary that comes with Apache (should be under apache/bin), using -cm flag for first user and -m for each additional
  4. create an (arbitrarily named/located) acl file (maybe called svn-acl) and assign permissions to users created in the previous step to groups and "projects" (directories) following this format:

# specify groups here
team1 = ross, rachel

# team1 group has a read/write access to project1 repository
# all subdirectories
# all others have read access only 
@team1 = rw
* = r

# project2 repository, only harry and sally have read-write access to project2
harry = rw
sally = rw
* = r

4. inside the subversion.conf create a virtual directory using the following format, including the acl file created in the previous step

<location project1="">
  DAV svn
  SVNPath C:/Repositories/project1

  AuthType Basic
  AuthName "Subversion Project1 repository"
  AuthUserFile c:/etc/svn-auth-file

  Require valid-user

  AuthzSVNAccessFile c:/etc/svn-acl