#3511 odeL returns spurious result for incorrect inputs; should give warning

[Daniel Volinski]

load(odes)$

odeL('diff(y,x) - (2 * x+3 * y + 1)/(4 * x+6 * y + 1), y, x); => y=matrix([])

Daniel

[Aleksas]

Function odeL is only for solving linear differential equation
Ly=f with constant coefficients.
For solving equation y' = (2 x + 3y + 1)/(4x + 6 y + 1) use contrib_ode or
change u=2x+3y.
In this case odeL must return "false" or some warning. I'm thinking about
updated version of package odes.

Merry Christmas

Aleksas D.

2018-12-18, an, 09:19 Daniel Volinski danielvolinski@users.sourceforge.net
rašė:

---

• [bugs:#3511] https://sourceforge.net/p/maxima/bugs/3511/ another odeL
  wrong result*

Status: open
Group: None
Created: Tue Dec 18, 2018 07:19 AM UTC by Daniel Volinski
Last Updated: Tue Dec 18, 2018 07:19 AM UTC
Owner: nobody

load(odes)$

odeL('diff(y,x) - (2 * x+3 * y + 1)/(4 * x+6 * y + 1), y, x); =>
y=matrix([])

Daniel

Sent from sourceforge.net because you indicated interest in
https://sourceforge.net/p/maxima/bugs/3511/

To unsubscribe from further messages, please visit
https://sourceforge.net/auth/subscriptions/

[Daniel Volinski]

Thanks Aleksas!

[Robert Dodier]

See also #3510 which is another example.