Re: symbolic, lazy Min

[Colin Macdonald]

On 2018-10-25 9:05 a.m., CS Suehs wrote:
> Greetings, all,
>
> I have been experiencing some pain trying to use sympy's Min from 
> Octave's symbolic
> math capabilities.  I have not been able to figure out how to dissuade 
> Octave from eagerly evaluating the Min.  I want an expression with a Min 
> in it, not an immediate attempt to evaluate the two expressions.  I 
> wonder, if Octave is confusing it with its own min, or failing to 
> translate the sym min to sympy's Min.  Perhaps, in my ignorance, I am 
> not correctly specifying the exact Min.

Probably this is because min(x,y) does not work correctly yet [1].

Here is a workaround:

>> syms x y
>> A = python_cmd('return Min(*_ins)', x, y)

>> syms p positive
>> B = python_cmd('return Min(*_ins)', p, 2*p)

I think [1] would be easy to fix properly and I'd love some help!  Just 
find "@sym/min.m" and edit it.  It needs to call sympy's "Min()" like 
the above examples.

[1] https://github.com/cbm755/octsympy/issues/876

Colin