Date Dreamer: where calendar dates meet fantasy!
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Date Dreamer: where calendar dates meet fantasy! Transforming calendar dates into surprisingly intriguing (and sometimes weird) plots.


What It Does

Date Dreamer can operate in 4 modes:

  1. UI-only: the plot is displayed in a graphical window.
  2. File-only: the plot is written to a PNG file.
  3. File-only with interim frames: the plot is rendered partially in frames, demonstrating the process.
  4. UI and File: where you can enjoy the graphical display and at the same time have the plot(s) saved as images.

See "Configuration Options" for information on how to configure different modes.


Here are 3 sample plots generated by datedreamer.

Date Dreamer - Sample Plot #3 Date Dreamer - Sample Plot #2 Date Dreamer - Sample Plot #1

How To Run

The only thing you need before running Date Dreamer is Java 1.7 and above. If you have it, then just download a release and follow the instructions in HOWTO_RUN file.

Note: Starting from release 0.6.0, the command line options have been replaced by a YAML configuration file which is self-descriptive.

Configuration Options

## Configuration options for Date Dreamer

# How many data points to generate?
# Though a bigger value means better precision, it comes at the price of speed
# and the size of the image. Usually 20000 is a good balance.
nPoints: 20000

# Where to output the plot?
# Can be 'file', 'ui' or 'both'.
outputMode: ui

# Where to write the image file?
# In case `outputMode` is set to `file` or `both`, this is the path to the file.
filePath: datedreamer.png

# What is the width of the image in pixels?
# Scales the width and height of the original image so that the width is
# `width`.
# For instance, if the original image is 300x100 and `width` is set to 800,
# the output dimensions will be 800x267.
width: 900

# What is the line color of the plot?
# In hex RGB format. Note `0x` at the beginning.
color: 0x6c008f

# Instructions for Date Dreamer to generate frames as the "dreaming" happens!
# If enabled, after generating certain number of points Date Dreamer will write
# the resulting (partial) plot to a file.
  # Is framed rendering enabled?
  # If set to `no`, none of the other options will have any effect whatsoever.
  # If set to `yes`, `filePath` and `nPoints` will have no effect.
  enabled: yes

  # In which directory to place the frames?
  # The directory should already exist and be accessible to Date Dreamer.
  directory: .
  # What is the prefix of the partial image files?
  # Date Dreamer will write image files with a simple naming convention:
  # `prefix+i`. For instance: `frame-0.png`, `frame-1.png`, ...
  prefix: 'frame-'

  # Should Date Dreamer show interim frames?
  # If you enable interim frames, then each frame will be represented as 2
  # frames: 1 with the portion rendered using `interimColor` and the other
  # one using `color`.
  showInterim: no

  # What is the line color of interim frames?
  # Only takes effect if `showInterim` is enabled.
  # Note `0x` at the beginning.
  interimColor: 0xff075f

  # Data to generate the frames. Each set contains the number of points in each
  # frame and the number of frames.
    - nPoints: 100
      nRepeat: 15
    - nPoints: 500
      nRepeat: 13
    - nPoints: 1000
      nRepeat: 13
# What is the initial seed to f(i)?
# Probably you don't need to change this. That said, take a look at the README 
# for a better understanding.
leap: 3

How It Works

Internally, the current date (or in future releases, the date you pass to it) is used to build a function. This function is then called N times, generating N data points. The list of data points is then converted to the list of partial sums of data points. And finally rendered to an image.

In math terms, given

Definition of Y, M and D

Definition of C1 and C2


Definition of f(i)

the points are generated using

Definition of g(n)

and then rendered as a line plot.


I got the idea from John D. Cook's website.