Allow keywords such as latex_name=LaTeX while defining symbolic function

[golam-m-hossain]

In new symbolics, underlying "sage.symbolic.function.SFunction" class allows one to pass the keywords such as "latex_name=LaTeX". It would be really good if we expose this feature at the user interface level. This will directly allow LaTeX customization by users according to their need.

Currently, Sage (4.0.1) raises error if one tries to do so.

Couple of example usage:

(1) Define symbolic function with its latex representaion

riemann(x) = function('riemann', x, latex_name="\\mathcal{R}")
latex( riemann(x) )
\mathcal{R}\left(x\right)

(2) Printing arguments of a symbolic functions as its indices.

mu,nu = var('mu,nu')
def my_latex_print(*args): 
    return "\psi_{%s}"%(', '.join(map(latex, args)))

psi(mu,nu) = function('psi', mu,nu, print_latex_func=my_latex_print)

latex(psi(mu,nu))
\psi_{\mu, \nu}

Attached patch allows keyword arguments while defining symbolic functions.

CC: @williamstein

Component: symbolics

Keywords: latex_name, symbolic function

Author: Golam Mortuza Hossain

Reviewer: Nick Alexander

Merged: 4.1.alpha0

Issue created by migration from https://trac.sagemath.org/ticket/6290

[golam-m-hossain]

Description changed:

--- 
+++ 
@@ -3,11 +3,11 @@
 Sage (4.0.1) raises error if one tries to do so.
 
 
-Example uses:
+Example usage:
 
 ```
 riemann(x) = function('riemann', x, latex_name="\\mathcal{R}")
 latex( riemann(x) )
-\mathcal{R}
+\mathcal{R}\left(x\right)
 ```
 

[golam-m-hossain]

Description changed:

--- 
+++ 
@@ -1,9 +1,11 @@
-In new symbolics, underlying "sage.symbolic.SFunction" class allows
-one to pass the keyword "latex_name=LaTeX". It would be really good if we expose this feature at the user interface level. Currently,
-Sage (4.0.1) raises error if one tries to do so.
+In new symbolics, underlying "sage.symbolic.function.SFunction" class allows one to pass the keywords such as "latex_name=LaTeX". It would be really good if we expose this feature at the user interface level. This will directly allow LaTeX customization by users according to their need.
+
+Currently, Sage (4.0.1) raises error if one tries to do so.
 
 
-Example usage:
+Couple of example usage:
+
+**(1)** Define symbolic function with its latex representaion
 
 ```
 riemann(x) = function('riemann', x, latex_name="\\mathcal{R}")
@@ -11,3 +13,21 @@
 \mathcal{R}\left(x\right)
 ```
 
+
+**(2)**   Printing arguments of a symbolic functions as its indices.
+
+```
+mu,nu = var('mu,nu')
+def my_latex_print(*args): 
+    return "\psi_{%s}"%(', '.join(map(latex, args)))
+
+psi(mu,nu) = function('psi', mu,nu, print_latex_func=my_latex_print)
+
+latex(psi(mu,nu))
+\psi_{\mu, \nu}
+```
+
+
+Attached patch allows keyword arguments while defining symbolic functions.
+
+

[williamstein]

comment:3

Nice. Could you add more to the docstring for function (at least the one that I get by default when I do function? from the sage prompt) that explains what happens to all kwds arguments? You do give a nice example (with riemann), but a sentence or two explaining what is going on would be very nice.

[golam-m-hossain]

Attachment: allow-keyword-arguments-such-as-latex_name-in-symbolic-functions.patch.gz

[golam-m-hossain]

comment:4

Replying to @williamstein:

Nice. Could you add more to the docstring for function (at least the one that I get by default when I do function? from the sage prompt) that explains what happens to all kwds arguments?

Thanks for your comments! As you suggested, I have updated the patch with expanded docstrings.

[ncalexan]

comment:5

Looks good to me.