Interaction between org tables and embedded calc

Interaction between org tables and embedded calc

[Gilles Charron]

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.  

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?


Thanks!
Gilles

Re: Interaction between org tables and embedded calc

[Eric Schulte]

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