Do X in Y: Install lens in Ubuntu linux

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Doug Rohde’s lens (light, efficient, neural simulator) is an awesome tool. However, given that it has not been actively maintained since 2000, its shelf-life is probably limited. I still have some legacy projects that were developed in lens (mainly using SRNs) and like to be able to re-run and tweak them. At some point, I’ll move them to tensorflow, but in the meantime, if I can get them running on linux, that would be great.

My primary linux box is a virtual machine under VirtualBox on a Mac running Ubuntu 18.04.1 LTS. I got lens running here by consulting this page. My notes are a bit more compact than the details at that page, and actually add crucial details now that it is hard to find legacy packages for tcl/tk.

  1. Get tcl and tk packages:
  2. Install those guys, following instructions like these, to wit:
    • sudo apt install ./name.deb
    • replace ‘name.deb’ with a package name; I assume you should tcl8.3 first, followed by tcl8.3-dev, tk8.3, and tk8.3-dev
  3. Choose where you will install lens. Personally, I like easy access to it right off my home directory in a folder called LENS.
  4. Download the code to that directory and unpack it:
    • sudo wget http://tedlab.mit.edu/~dr/Lens/Dist/lens.tar.gz
    • sudo tar zxf lens.tar.gz
    • sudo rm lens.tar.gz
  5. Replace every instance of CLK_TCK with CLOCKS_PER_SEC in the files in Src; a one-line way of doing this from this page:
    • sed -i 's%CLK_TCK%CLOCKS_PER_SEC%g' ./Src/command.c ./TclTk/tcl8.3.4/unix/tclUnixPort.h
  6.  In Src/system.h, comment out the “include <bits/nan.h>” line; those functions have been integrated into math.h, which is also included. Not doing this leads to errors at compile.
  7. Edit the Makefile. Minimally, replace the line “CFLAGS = -Wall -O4 -march=i486” with “CFLAGS = -Wall -O4“. I also had some weird problems where it was generating a HOSTTYPE directory for i586 that would not work that went away when I simply commented out every other HOSTTYPE section except the default one. Inelegant, but it worked.
  8. Then build it: sudo make all 
    • If it didn’t work, I’m sorry. That’s all I’ve got…
  9.  Then deviate slightly from the installation directions. In your ~/.bashrc, add these lines (and save it and then start a new terminal or ‘source ~/.bashrc‘):
    • export LENSDIR=${HOME}/LENS # or whatever your location is
    • export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${LENSDIR}/Bin
    • export PATH=${PATH}:${LD_LIBRARY_PATH}:${LENSDIR}/Bin
  10. You should now be able to execute lens anywhere by typing ‘lens‘