Properties and Columns

Properties and Columns

[Dennis Groves (CISG)]

I just read about this in the manual, as prompted by trying to understand
how Mikael tracks his exercise and stuff compared to mine. Basically, I
converted a bunch of my old spreadsheets to org-spreadsheet-tables.

Can anbody give me some examples of how they use the Properties and Columns
stuff - it looks like that would be way more flexible and useful than what I
did with all my spreadsheets...

How would you do calculations for calculated or derived data from the data
points you do gather? (for example, I do lean body mass calculations based
on a number of physical metrics I gather each day...)

I like the stuff I read, but I am not certain how to implement it.

Dennis

Re: Properties and Columns

[Mikael Fornius]

"Dennis Groves (CISG)" <degroves@microsoft.com> writes:

> Can anbody give me some examples of how they use the Properties and Columns
> stuff - it looks like that would be way more flexible and useful than what I
> did with all my spreadsheets...

Say we want to collect body weight data. I would make notes of my weight
in a timestamped heading with the weight as property:

M-RET
C-c . RET
M-x org-set-property

Results in entry:

* <2008-11-07 fre>
  :PROPERTIES:
  :weight:   68
  :END:

With point on property-drawer magic key C-c C-c makes adding more or
editing properties easy.

Now I define what columns to show with: 

#+COLUMNS: %TIMESTAMP %weight

now when doing C-c C-x C-c on the heading will show the data as a table
row instead of a heading. Columns can be defined globally (as I did in
my example) or for a subtree by setting :COLUMNS: property in root of
folding tree.

For more info see info page
M-: (info "(org) Properties and Columns")

Personally I think it is cool to be able to view headings as columns
although the alignment of the columns is not in a straight line when
viewing over many subtrees.

It is nice that org-columns preserves the tree view you have folded, so
you can limit your columns view with tag searches.

At the top of the columns table there is headlines and you can tell org
to sum a column and have it displayed, sum times or numbers. Thats it as
far as I know.

> How would you do calculations for calculated or derived data from the data
> points you do gather? (for example, I do lean body mass calculations based
> on a number of physical metrics I gather each day...)

You can dump a org-columns view to a standard org-table with a dynamic
block, then maybe apply some table formulas on it for more advanced use.

I am not sure if the TABLEFM can be kept outside of the dblock? (So it
is not erased when updating.)

/Mikael Fornius