I believe every programmer has his/her own repository of coding snippets. I used to manage it with OneNote and EverNote. I am going to manage the core part here.

python

  • Iterate through all files in the current folder.
import os

for root, dirs, files in os.walk(os.getcwd()):
    for name in files:
        print(os.path.join(root, name))

MATLAB

  • Iterate through all files in the current folder and remove the root folders.
dirInput = dir(fpath);
dirInput(ismember({dirInput.name},{'.','..'})) = []; % remove hidden folder
  • Make directory if not exist (one liner).
dirname = "name";
if ~exist(dirname, 'dir'), mkdir(dirname); end
  • Spherical VOI out of a matrix
    I learned this from Dr. Qianqian Fang’s MCX demo code.
[yy xx zz] = meshgrid(1:60,1:60,1:60);
S = double(sqrt((xx-30).^2+(yy-30).^2+(zz-30).^2)<=15);
  • To define input arguments with "name", "value" pairs
function testarg(x, y, varargin)
params.name_1 = 0;
params.name_2 = 0;

input_params = struct(varargin{:});
keys = fieldnames(input_params);
if nargin>2
  for i = 1:length(input_params)
      cur_key = keys{i};
      if isfield(params, cur_key)
          params.(cur_key) = input_params.(cur_key); 
      else
          warning("Unable to recognize '%s'", cur_key)
      end
  end
end

>>> testarg(x, y, 'name_1', 1)

Imagemagick

  • Make gif from image frames.
magick convert -delay 10 -loop 0 *.png animated.gif
Flag Meaning
-delay Frame duration $x \times 10$ ms
-loop Number of loops, 0 for infinity

ffmpeg

  • Make mp4 from image frames
ffmpeg -framerate 30 -pattern_type glob -i 'Output_%3d.png' -c:v libx264 -pix_fmt yuv420p out.mp4

Refer to the manual for information. However, the -pattern_type glob command is not supported by Windows.