DEQ
ODEs Two reverse
Reverses to find initial values in ODE's. UNDER CONSTRUCTION
2026.Apr.10 18:13:38
tf, tR   (tR := min(tf, tR)) Times: final integration (from 0) and report.
Target F values Target function values at tR.
Initial values Values at t = 0 (IVs).
Parameters Parameters (such as rates).
Integration method        Method of integration.
Computation mode     Mode, and termination tolerance.
Minimization method Python 'optimization minimization' method.
Points N. of points in plot
Show values Show graph coordinates.

Integrates the ODEs from time 0 to tf. Reports the function values at tR.

The embedded ODE's are: x' = -x + p x y, y' = -y + q x², with given initial values.

This applies, from Python: for integration, 'scipy.integrate' 'odeint'; and, for optimization, 'minimize'.

Draws a plot of the integrated functions.

ODEs

Computation structure — A PHP file (this page: 'P.ode2.php') calls (via 'action=...') an intermediate PHP file ('Ode2.php'), which (through $_POST) sends the problem data as command line arguments to a Python script. This last does the computing, and makes 'system' call(s) to 'gnuplot', for the final (temporary) webpage.

Keywords: ODEs two; reverse kinetics; Python; gnuplot.

References: Plate: reverseODEsTwo

• Python minimize [in Optimization and root finding (scipy.optimize)].

• Gnuplot dashtype • HTML Color Codes • Python f-string • (Python) unicode characters

• CISTI'2027, 22.ª Conferência Ibérica de Sistemas e Tecnologias de Informaçaão (22.nd Iberian Conference on Information Systems and Technologies), #... (Portugal), #25–28 June 2027.

• 1902-04-04: Hopf, Eberhard Frederich Ferdinand (†1983-07-24, 81 yrs.).

 
 
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Created: 2026-04-04 — Last modified: 2026-04-10