Re: LIterate programming with calc (help)

Re: LIterate programming with calc (help)

[Ypo]

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Just in case you find this package interesting. Except some problems 
with units conversion, it's nice:

https://github.com/sulami/literate-calc-mode.el

> This is a literate calc file.
>
> Lines without "=" are ignored.
>
> All results starting with "=>" are an overlay generated by
> literate-calc-mode. That means they are displayed in Emacs, but not
> actually in the buffer/file contents.
>
> We can calculate a value like so:
>
> = 2 + 2 => 4
>
> If there is any string on the left hand side, it becomes a bound
> variable.
>
> Pi = 3.14159 => Pi: 3.14159
>
> We can use this variable below the definiton.
>
> Tau = Pi * 2 => Tau: 6.28318
>
> Results are calculated using Emacs' own calc, so you can use formulas
> as well.
>
> = round(Pi, 2) => 3.14
>
> Later bindings shadow earlier ones:
>
> Pi = 3 => Pi: 3
>
> = Pi => 3
>
> Variable names can have spaces as well:
>
> Monthly Expenses = 500 => Monthly Expenses: 500
>
> Monthly Income = 1000 => Monthly Income: 1000
>
> Annual Savings = 12 * (Monthly Income - Monthly Expenses) => Annual Savings: 6000
>
> All values are recalculated on every update in a spreadsheet-like
> fashion.
>
> Calc also has a lot of advanced features, like arrays:
>
> Numbers = [1 2 3] => Numbers: [1, 2, 3]
>
> = 3 Numbers => [3, 6, 9]


> "Fraga, Eric"<e.fraga@ucl.ac.uk>  writes:
>
> >/> I guess that the main problem is that calc is tightly integrated with/
> >/> interactive commands. Maybe ob-calc could be extended to somehow/
> >/> indicate the commands to be executed in addition to inputting stack/
> >/> entries./
> >/>/
> >/> Not sure if there is much interest in such feature though./
> >
> >/Thinking out loud, what would be better, but I have no idea how feasible/
> >/it would be, would be to have ob-calc make use of the embedded calc/
> >/functionality and syntax, so that you could write something like this:/
> >
> >/#+begin_src calc/
> >/a := 300 m/
> >/b := 2 a =>/
> >/#+end_src/
> >
> >/which would output the result of any line with => on it./
>
> I am CCing Tom Gillespie, the maintainer of ob-calc. Maybe he has
> something to say.

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Re: Literate programming with calc (help)

[Ypo]

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I have discovered, taking a look at the Org Manual, that exists an 
embedded mode for Calc.

https://www.gnu.org/software/emacs/manual/html_mono/calc.html#Assignments-in-Embedded-Mode

Using "C-x * e" it solves this kind of formula with units:

a := 3 m / s

t := 7 s

a t =>



> > From:     Ihor Radchenko
> > Subject:     Re: LIterate programming with calc (help)
> > Date:     Tue, 01 Nov 2022 07:22:18 +0000
>
> ------------------------------------------------------------------------
> "Fraga, Eric"<e.fraga@ucl.ac.uk>  writes:
>
> >/> I guess that the main problem is that calc is tightly integrated with/
> >/> interactive commands. Maybe ob-calc could be extended to somehow/
> >/> indicate the commands to be executed in addition to inputting stack/
> >/> entries./
> >/>/
> >/> Not sure if there is much interest in such feature though./
> >//
> >/Thinking out loud, what would be better, but I have no idea how feasible/
> >/it would be, would be to have ob-calc make use of the embedded calc/
> >/functionality and syntax, so that you could write something like this:/
> >//
> >/#+begin_src calc/
> >/a := 300 m/
> >/b := 2 a =>/
> >/#+end_src/
> >//
> >/which would output the result of any line with => on it./
>
> I am CCing Tom Gillespie, the maintainer of ob-calc. Maybe he has
> something to say.
>
> -- 
> Ihor Radchenko // yantar92,
> Org mode contributor,
> Learn more about Org mode at <https://orgmode.org/>.
> Support Org development at <https://liberapay.com/org-mode>,
> or support my work at <https://liberapay.com/yantar92>
>
>
>
> 	
>
> 	
>
> 	
>

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LIterate programming with calc (help)

[Ypo]

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Is it possible to express in a calc block some basic operations with 
variables and non-predefined units?


For example, if you wanted to build a code block that calculates how 
much money costs:

a land with an Area of 300x300 m^2 at a price of 1 $/m^2.


Would it be something like this?

#+begin_src calc
   a = 300 m
   b = 300 m
   Area = a*b
   cost = 1 ($/m^2)
   A*c

#+end_src


Is it possible to work with the "$" unit?

Why A*c won't show an arithmetic result, but ~: A c ~?

Wanted result is:


#+RESULTS:
: 90 000 $


Best regards

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Re: LIterate programming with calc (help)

[Fraga, Eric]

On Sunday, 23 Oct 2022 at 14:15, Ypo wrote:
> Is it possible to express in a calc block some basic operations with
> variables and non-predefined units?

> Why A*c won't show an arithmetic result, but ~: A c ~?

I've never managed to get calc blocks define variables.  The equations
you have typed in are "equations" in the mathematical sense, not
assignment statements.

> Is it possible to work with the "$" unit?

$ means something specific in calc (cannot remember what).  I use "USD"
instead, for instance, and it works fine.

The following single line calc block does do what you want:

#+begin_src calc
  solve([a = 300 m, b = 300 m, Area = a*b, cost = 1 (USD/m^2), z = Area*cost], [a, b, Area, cost, z])
#+end_src

#+results:
: [a = 300 m, b = 300 m, Area = 90000 m^2, cost = USD / m^2, z = 90000 USD]

-- 
: Eric S Fraga, with org release_9.5.5-966-g88c85d in Emacs 29.0.50

Re: LIterate programming with calc (help)

[Ihor Radchenko]

"Fraga, Eric" <e.fraga@ucl.ac.uk> writes:

> On Sunday, 23 Oct 2022 at 14:15, Ypo wrote:
>> Is it possible to express in a calc block some basic operations with
>> variables and non-predefined units?
>
>> Why A*c won't show an arithmetic result, but ~: A c ~?
>
> I've never managed to get calc blocks define variables.  The equations
> you have typed in are "equations" in the mathematical sense, not
> assignment statements.

I vaguely recall that storing variables in calc is something like
variable := assignment (which is actually rewrite rule, but that's how
13.1 Storing Variables section of the calc manual explains variable
assignments).

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: LIterate programming with calc (help)

[Fraga, Eric]

On Monday, 24 Oct 2022 at 09:20, Ihor Radchenko wrote:
> I vaguely recall that storing variables in calc is something like
> variable := assignment (which is actually rewrite rule, but that's how
> 13.1 Storing Variables section of the calc manual explains variable
> assignments).

That is true for embedded calc (which I use all the time) but I cannot
seem to get this to work for src blocks:

#+begin_src calc
  a := 300 m
  2 a
#+end_src

#+results:
: 2 a

whereas embedded mode works fine:

a := 300 m

and

2 a => 600 m

I really do not understand how calc src blocks work (I've not looked at
the code, mind you).

-- 
: Eric S Fraga, with org release_9.5.5-966-g88c85d in Emacs 29.0.50

Re: LIterate programming with calc (help)

[Christian Moe]

Fraga, Eric writes:

> On Monday, 24 Oct 2022 at 09:20, Ihor Radchenko wrote:
>> I vaguely recall that storing variables in calc is something like
>> variable := assignment (which is actually rewrite rule, but that's how
>> 13.1 Storing Variables section of the calc manual explains variable
>> assignments).
>
> That is true for embedded calc (which I use all the time) but I cannot
> seem to get this to work for src blocks:


Same: it requires using the `s s' (calc-store) command, though (which
can also be done without the := assignment operator), and I've searched
the manual without spotting a way to do that with algebraic entry and
hence in a src block, as there doesn't seem to be any corresponding
command. I hope there is a way, though!

As an unsatisfying workaround, one could use :var header arguments; they
work up to a point, but not with units, as Ypo wants to use (and which
are are a really cool thing about Calc).

Once one's using variables, it will probably be necessary to wrap the
final calculation in evalv() to get a numeric value as output instead of
a formula with the variable names in it.

Another obstacle to what Ypo is trying to do is the attempt to use the $
sign for the currency unit. Calc does not have pre-defined currency
units, and $ is taken - it refers to the last value on stack. I tend to
use 'USD'.

So a partial, if pointless, way to do this would be to first store the
variables with the calculator:

  ' 300 m
    s s a       # store a = 300 m
  ' 300 m
    s s b       # store b = 300 m
  ' 1 USD/m^2
    s s cost    # store cost = (1) usd/m^2
  ' a*b
    s s Area    # store Area = a*b (*not* 90000 m^2)

Then the last step could be done in a src block:

  #+begin_src calc
    evalv(Area * cost)
  #+end_src

  #+RESULTS:
  : 90000 USD

(Another cool bit: If you change the value of a or b and rerun the src
block, the result will change, since what was stored in Area was the
product of the variables, not the product of their values.)

Yours,
Christian

Re: LIterate programming with calc (help)

[Ypo]

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Not bad, thanks!!!

Why do you think it doesn't work something more human readable like this?

#+begin_src calc
                solve([
                a = 300 m,
                b = 300 m,
                Area = a*b,
                cost = 1 (USD/m^2),
                z = Area*cost

                ], [a, b, Area, cost, z])
#+end_src


Best regards


El 24/10/2022 a las 9:56, Fraga, Eric escribió:
> On Sunday, 23 Oct 2022 at 14:15, Ypo wrote:
>> Is it possible to express in a calc block some basic operations with
>> variables and non-predefined units?
>> Why A*c won't show an arithmetic result, but ~: A c ~?
> I've never managed to get calc blocks define variables.  The equations
> you have typed in are "equations" in the mathematical sense, not
> assignment statements.
>
>> Is it possible to work with the "$" unit?
> $ means something specific in calc (cannot remember what).  I use "USD"
> instead, for instance, and it works fine.
>
> The following single line calc block does do what you want:
>
> #+begin_src calc
>    solve([a = 300 m, b = 300 m, Area = a*b, cost = 1 (USD/m^2), z = Area*cost], [a, b, Area, cost, z])
> #+end_src
>
> #+results:
> : [a = 300 m, b = 300 m, Area = 90000 m^2, cost = USD / m^2, z = 90000 USD]
>

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Re: LIterate programming with calc (help)

[Fraga, Eric]

On Monday, 24 Oct 2022 at 13:26, Ypo wrote:
> Why do you think it doesn't work something more human readable like this?
>
> #+begin_src calc
>                solve([
>                a = 300 m,
>                b = 300 m,
>                Area = a*b,
>                cost = 1 (USD/m^2),
>                z = Area*cost
>
>                ], [a, b, Area, cost, z])
> #+end_src

It only parses a line at a line unfortunately.  This would work in
Maxima, mind you. ;-)  (with some minor change in syntax, of course)

-- 
: Eric S Fraga, with org release_9.5.5-966-g88c85d in Emacs 29.0.50

Re: LIterate programming with calc (help)

[Ihor Radchenko]

Ypo <ypuntot@gmail.com> writes:

> Would it be something like this?
>
> #+begin_src calc
>    a = 300 m
>    b = 300 m
>    Area = a*b
>    cost = 1 ($/m^2)
>    A*c
>
> #+end_src

I looked into ob-calc and it looks like the way to define variables is
via :var header argument.

Other than that, ob-calc simply does what calc would do if you type the
above into calc stack. Which would also yield nothing.

I guess that the main problem is that calc is tightly integrated with
interactive commands. Maybe ob-calc could be extended to somehow
indicate the commands to be executed in addition to inputting stack
entries.

Not sure if there is much interest in such feature though.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: LIterate programming with calc (help)

[Fraga, Eric]

On Monday, 31 Oct 2022 at 09:23, Ihor Radchenko wrote:
> I looked into ob-calc and it looks like the way to define variables is
> via :var header argument.

Indeed.  Something like :var a="300 m" does work.

> I guess that the main problem is that calc is tightly integrated with
> interactive commands. Maybe ob-calc could be extended to somehow
> indicate the commands to be executed in addition to inputting stack
> entries.
>
> Not sure if there is much interest in such feature though.

Thinking out loud, what would be better, but I have no idea how feasible
it would be, would be to have ob-calc make use of the embedded calc
functionality and syntax, so that you could write something like this:

#+begin_src calc
a := 300 m
b := 2 a =>
#+end_src

which would output the result of any line with => on it.

-- 
: Eric S Fraga, with org release_9.5.5-1028-gcd835d in Emacs 29.0.50

Re: LIterate programming with calc (help)

[Ihor Radchenko]

"Fraga, Eric" <e.fraga@ucl.ac.uk> writes:

>> I guess that the main problem is that calc is tightly integrated with
>> interactive commands. Maybe ob-calc could be extended to somehow
>> indicate the commands to be executed in addition to inputting stack
>> entries.
>>
>> Not sure if there is much interest in such feature though.
>
> Thinking out loud, what would be better, but I have no idea how feasible
> it would be, would be to have ob-calc make use of the embedded calc
> functionality and syntax, so that you could write something like this:
>
> #+begin_src calc
> a := 300 m
> b := 2 a =>
> #+end_src
>
> which would output the result of any line with => on it.

I am CCing Tom Gillespie, the maintainer of ob-calc. Maybe he has
something to say.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>