Submitted small bug-fix to iPhone Spelling Toy February 10th, 2010
Patrick Stein

I just uploaded the first update to my iPhone Spelling Toy. The update includes two minor changes:

  • Corrected spelling of siete (Spanish for seven)
  • Corrected spelling of colores (Spanish for colors)

Today, I am working on adding animal drawings.

Lisp Fourier Transform Library Faster Yet (v1.3) October 13th, 2009
Patrick Stein

I released version 1.3 of my Common Lisp Fourier Transform library today. It is significantly faster than yesterday’s version. On my MacBook Pro in SBCL 1.0.30 with a 512 by 512 by 16 array, version 1.3 takes 3.74 seconds where version 1.2 took 9.77 seconds and version 1.0 took 25.31 seconds. For a breakdown of performance on various array sizes with various Lisp implementations, see the performance section of the library page.

Most of the speed improvement in this version came from memory improvements. Version 1.3 doesn’t cons at all in SBCL during the processing of each row. Version 1.2 inadvertently consed three rows worth of complex numbers for every row transformed.

My library is still about 25% slower than Bordeaux FFT for one-dimensional arrays. My library, however, has full support for multi-dimensional arrays where Bordeaux-FFT does not.

I also included some validation test cases using NST to this release. To try them, go to the library directory, hop in your Lisp, and load regression.lisp.

Lisp Fourier Transform Library Faster October 12th, 2009
Patrick Stein

I released version 1.2 of my Common Lisp Fourier Transform library today. It is significantly faster than the old version. On my MacBook Pro in SBCL 1.0.30 with a 512 by 512 by 16 array, version 1.2 takes 9.77 seconds where version 1.0 took 25.31 seconds. Version 1.2 consed 2.4M while version 1.0 consed 7.4M. Neither version should have to cons nearly that much, so there’s still work to be done.

This release is significantly faster under Clozure64 1.3-r11936, too. For a 512 by 512 array, version 1.2 takes 2.72 seconds (single-threaded) and 2.07 seconds (multi-threaded) where version 1.0 took 4.45 seconds (single-threaded) and 3.06 seconds (multi-threaded).

My library is still about 1/2 to 1/3 the speed of Bordeaux FFT and still allocates memory in situations that Bordeaux does not. Hopefully, I can close those gaps most of the way soon.

geoma v1.2.2007.08.20 August 20th, 2007
Patrick Stein

This version simply contains some tweaks to deal with more modern C++ compilers.

rt v2.7.2007.05.17 May 17th, 2007
Patrick Stein

  • The documentation
  • The source code
  • The feature set now includes:
    • Phong shading, reflection, refraction
    • Functional textures (including textures generated by
      raytracing other scenes)
    • Cylinders (including spheres and cubes)
    • Quadratic surfaces
    • Regular polytopes
    • Halfspaces
    • Convex hulls of a sets of points
    • Extrusions of lower-dimensional objects
    • Intersections, unions, and complements
    • Different colors for k-dimensional subfacets
      of convex hulls and coxeter polytopes
  • Here are some sample images:
    • A stereo pair of slices of some 24-cells along with the input file. The vertexes (0-facets) are pink, the edges (1-facets) are dark gray, the faces (2-facets) are yellowish, and the facets (3-facets) are green.
    • Some 3-D polytopes with edges and vertexes colored differently and the input file.

 

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