Summary

The lowest threshold way to record your body weight is to use a printed page of custom grid paper and make a pen mark on the page every day. weight-calendar-grid creates PDF files of that grid paper.

• Initial setup:

  1. Print a page with your grid.

  2. Hang printed page on wall or put it in similarly easily available space close to the scale.

  3. Keep a dedicated pen at that very location.

• Daily:

  1. Step on scale and read the weight.

  2. Mark that day's weight on the page.

• Every few weeks or months:

  1. Print a new page and replace the old page with it.

  2. Optionally, type the marked values into some computer file.

To print a page, create a PDF file with wcg-cli and print that.

Example for someone of 1.78m height and a weight of around 85kg:

$ ./wcg-cli -o my-weight.pdf --height=1.78 --weight=80-90

Example for someone of unspecified height and a weight of around 85kg:

$ ./wcg-cli -o my-weight.pdf --weight=85+-5

Example for someone of 1.78m height and normal weight:

$ ./wcg-cli -o my-weight.pdf --height=1.78

For detailed information on how to call wcg-cli, read the output of

$ ./wcg-cli --help

Rationale

I need a very low overhead way to record my weight to reliably do it. However, just writing down a numerical value on paper does not help much as I cannot immediately see how that value relates to the previous ones.

Typing the value into a computer program and letting the program plot the values helps, but is too much hassle. The same applies to smartphone apps.

Recording values on common off the shelf grid paper does not work as the 5x5mm or 1x1mm grids are not well suited for date and kg ranges.

So I need a custom type of grid paper to record my weight on. This custom grid paper does multiple things:

• I can immediately see how the last recorded value relates to the previous ones and reasonably estimate a trend.

• Marking the current value is a matter of seconds and has instantanous results: The visual extrapolation is instantaneous.

• If I want to keep longer term records on the computer, I have recorded values with 0.1kg precision which can easily be read from the diagram and then typed into the computer.

So as long as the scale can neither record the weight nor display the graph, this turns out to be the best way to keep track of my weight.

Recording Details

This program can plot recorded weight values into the grid paper it prints. For this to happen, you need to keep long term records of your measured weights in a simple text file foo.dat where every line looks as follows:

# my weights

# YYYY-MM-DD   kg
2011-05-23     82.3
2011-05-24     81.7
2011-05-25     82.1
2011-05-26     82.5

2011-06-03     81.6
2011-06-04     81.8
2011-06-05     81.3
2011-06-06     81.7

Feed this file to wcg-cli with the --input= option and play around with the --begin date for an actual plot. The auto weight range might be useful.

GUI

The Gtk3 based GUI script wcg-gui is a definite Work In Progress.

Web Service

A web service with an HTML5 webapp might be an interesting way to supply many people with weight calendar grid PDFs for printing out themselves. We have nothing implemented yet in this department, though.

Requirements

• Python3

  We do not support Python 2.

• pdflatex and TikZ if you want really nice looking PDFs

• ReportLab if you want to hack on the ReportLab based PDF driver

• Gtk3 if you want to run the GUI

• cairo and pycairo if you want basic PDFs without pdflatex or if you want the GUI

• gettext for the translations

Build and Install

After the git clone, run

$ python3 setup.py build

After that, you can run ./wcg-cli and ./wcg-gui from the source tree or install the weight-calendar-grid package with

$ python3 setup.py install

Run with --help for details on installing somewhere specific.

Development

Debugging

When running wcg-cli, you can set up the startup log level by setting WCG_LOG_LEVEL like so:

$ env WCG_LOG_LEVEL=verbose ./wcg-cli

Additional -q and -v parameters are optional and make the output one level more quiet or more verbose, respectively.

Testing

To run the set suite:

$ python3 setup.py test

You can set a few environment variables to influence the tests:

• WCG_TEST_KEEP=yes Keep around the files the tests generate.

• WCG_TEST_DRIVERS=cairo,reportlab,tikz

  Only test the drivers listed here in the comprehensive tests as those tests are many and tikz/pdflatex runs SO much longer than the other drivers. The valid drivers are the same as listed by wcg-cli --list-options.

Translations

• After adding, changing or removing translated strings in the Python source code:

  $ python3 setup.py extract_messages
  $ python3 setup.py update_catalog
  

  If you run into a TypeError exception, see below.

• After updating a translation in weight_cal_grid/locale/${LANG}/LC_MESSAGES/weight-calendar-grid.po, compile that file to its binary equivalent weight_cal_grid/locale/${LANG}/LC_MESSAGES/weight-calendar-grid.mo:

  $ python3 setup.py compile_catalog
  

• Create translation for a new language:

  $ python3 setup.py init_catalog --locale=${NEW_LANG}
  

• On Python 3.4 and Babel 1.3, you might run into an exception like

  File "/usr/lib/python3.4/site-packages/babel/messages/frontend.py", line 585, in run
      include_previous=self.previous, width=self.width)
  File "/usr/lib/python3.4/site-packages/babel/messages/pofile.py", line 446, in write_po
     _write(comment_header + u'\n')
  File "/usr/lib/python3.4/site-packages/babel/messages/pofile.py", line 390, in _write
     fileobj.write(text)
  TypeError: must be str, not bytes
  

  If you don't want to update your system to Babel 2.0 or newer, you can edit /usr/lib/python3.4/site-packages/babel/messages/frontend.py line 580 from

  580             tmpfile = open(tmpname, 'w')
  

  to

  580             tmpfile = open(tmpname, 'wb')
  

  which solves the issue.