Category "IDL"


IDL 8.7.3 was released recently1. The new features are:

  1. Using the Intel Math Kernel Library (MKL) for matrix operations now. My experience has been that MKL is a highly optimized implementation of BLAS, a library of low-level matrix and vector operations. Matrix operations, such as the # and ##, should be faster now, but I don't have 8.7.3 to test on, yet.
  2. New BLASS_GEMM matrix multiplication routine with many options for controlling the operation. This is a consequence of adding the MKL.
  3. New SOBOLSEQUENCE routine to generate numbers from the Sobel sequence.

UPDATE 2/25/2020: I have IDL 8.7.3 now and did some simple testing of the performance between IDL 8.7.3 and IDL 8.6 for # and ##. Mean time for multiplying two 50,000 by 50,000 element matrices went from 76.942 sec in IDL 8.6 down to 3.400 sec in IDL 8.7.3.


  1. I have no idea exactly when or how to find that out. ?

IDL 8.7.2 was released sometime last year1. Check out the What's New for more details. The big feature is the WIDGET_BROWSER, which allows a browser window to be embedded in an IDL widget program.


  1. I only know because I saw a webinar for the IDL 8.7.3 release, so it must have been awhile ago. 

I updated my groceries list app, [Quantified Groceries], today. It's updated for recent phones and also now has a dark mode.

The release notes for 1.1.0:

- [NEW] iPhone XS/XR screen size support
- [NEW] Dark mode
- [NEW] Haptic feedback (requires iPhone 7 or later)

[Quantified Groceries]: https://michaelgalloy.com/quantified-groceries
[iOS App Store]: https://itunes.apple.com/us/app/quantified-groceries/id1099663281

IDL 8.7.1 adds the IDL Package Manager (IPM), a package manager for IDL libraries. You can install libraries from the Internet with a single command in IDL, even installing dependencies for the library if needed.

Continue reading "IDL Package Manager."

IDL 8.7.1 was released today. Check the What's New on the Docs Center for a comprehensive list of the new features.

Along with some performance improvements and library updates, there are two big new features:

  • an IDL package manager
  • machine learning classes (including a feed forward neural network class)

I will publish an article about the package manager shortly; I made IDLdoc, mgunit, and my personal library available through the package manager. I think this is now the best way to distribute IDL packages.

I am also excited to explore the machine learning classes. I will write more as soon we get 8.7.1 installed on our machines.

With these two new features, this is a powerful "bug fix" release.

When working with data files at my day job, I often come across directories containing a large number of files of several distinct types. It would be useful to produce a listing of the files clustered into these types. I wrote `cls` (Clustered ls) to find patterns in filenames for display.

Continue reading "Clustered ls."

Circular law states the eigenvalues of a matrix with random entries of mean 0 and variance 1/n are approximately uniformly distributed in the unit disk of the complex plane. To see this, create a random matrix:

n = 1000
x = randomu(seed, n, n) - 0.5
x *= sqrt(12.0 / n)

Find the eigenvalues:

eigenvalues = la_eigenproblem(x, eigenvectors=eigenvectors)

Plot them:

plot, real_part(eigenvalues), imaginary(eigenvalues), $
      psym=3, $
      xstyle=1, xrange=[-1.5, 1.5], $
      ystyle=1, yrange=[-1.5, 1.5]

This gives a plot like below:

Via the excellent John D. Cook blog. I recommend reading his site if you are interested in a combination of mathematics and Python.

[IDLdoc][repo] 3.6.2 has been released! New features include:

* Bug fix for image directive for image files in other directories specified
with a relative path (fix by Dave Gellman).

* Only copying MathJax for LaTeX-style equations if not already present.

* Fixed crash when invalid format/markup was specified on the docformat line of
a `.pro` file.

[repo]: https://github.com/mgalloy/idldoc/ "mgalloy/idldoc"
[download]: https://github.com/mgalloy/idldoc/wiki/Releases "IDLdoc releases"

[mgunit][repo] 1.6 has been released! New features include:

* Fix for bug when no filename with jUnit output format

* Recursively search directories below test suite home directory for `*_ut.pro`
and `*_uts.pro` files

* Fixed for bug in `mguttestsuite_define::addTestingFolder` that did not add
absolute paths correctly

* Add superclasses of test classes recursively

You can [download] a distribution with a `.sav` file and documentation, or just access the [repo] as needed.

[repo]: https://github.com/mgalloy/mgunit/ "mgalloy/mgunit"
[download]: https://github.com/mgalloy/mgunit/wiki/Releases "mgunit releases"

IDL 8.7 was released recently. The listed features are:

- `ROUTINE_DIR` function that returns the directory for the file containing the calling routine
- asynchronous job classes
- a few miscellaneous other updates

The asynchronous job classes look interesting:

> The IDLAsync classes allow you to specify units of work to execute asynchronously outside the main IDL session. To do this, create an IDLAsyncQueue and one or more IDLAsyncJob objects that encapsulate the work to be performed. As jobs are added to the queue, they will be executed at some point in the future as resources are available. When a job is complete, you can retrieve its results for further use. You can also construct an IDLAsyncJoin object and pass it into the jobs on creation. If you do this, you can wait on the join object for all of the jobs it observes to be finished before continuing.

Check the [release notes] for more details.

[release notes]: http://www.harrisgeospatial.com/docs/whatsnew.html

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