Re: Interaction between org tables and embedded calc

[Eric Schulte <eric.schulte@gmx.com>]

Gilles Charron <gilles.charron@gmail.com> writes:

> Hi,
>
>   I recently discovered the beauty of emacs embedded calc.  Works great inside
> org files for note taking with math & engineering related content.   
>
> I've been trying to get org tables and embedded calc to coordinate with each
> other using assigned variables however it appears that embedded calc uses some
> sort of namespace for storing variables.  Below is a sample of what I'm trying
> to do:
>
> Let's say I need to calculate something - I'll assign it to an embedded calc
> variable:
>
> myVariable := 1 + 0.5 =>  1.5
>
> Now, embedded calc knows about "myVariable" .  Next I would like to use this
> variable inside a org table (like offset all elements in a column with
> "myVariable"):
>
> | Data | Corrected Data (-myVariable) |
> | 0    | should yield -1.5            |
> | 1    | should yield -0.5            |
> | 2    | should yield  0.5            |
>
> I've been trying to use calc-eval along with evalv however they don't appear to
> resolve "myVariable".   
>
> Reading though the embedded calc documentation:
>
>
> "The assignment operator `a := 17' does not actually do anything by itself. But
> Embedded Mode recognizes it and marks it as a sort of file-local definition of
> the variable."
>
> How can I access these "file-local definitions" through "calc-eval" or org
> tables?  Essentially, I'm looking for an equivalent of org properties
> "$PROP_propertyName" which can be accessed in org tables.  
>

This is an interesting question but to the extent that you're asking how
to resolve an embedded calc variable from general calc execution I think
this is more of a calc than an Org-mode question, and should be sent to
the calc mailing list.

>
> I would also like the ability to read from an org table and use the
> content later in a embedded math equation:
>
> | Data |
> |------|
> | 1    |
> | 2    |
> | 3    |
> |------|
> | 6    |
> #+TBLFM: @5$1=vsum(@I..II)
>
> Would like to read the results (6) and use it in a equation:
>
> MoreProcessing := $result + 1.234
>
> How would one go about doing this?
>

Assuming you know the syntax to specify vectors in embedded calc, you
could use a code block to read the table from Org-mode and output the
calc vector syntax into your document.

Best,

>
>
> Thanks!
> Gilles
>
>

-- 
Eric Schulte
http://cs.unm.edu/~eschulte