Progress Bar Integration

DifferentialEquations.jl integrates with the Juno progress bar in order to make long calculations more manageable. By default, this feature is off for ODE and SDE solvers, but can be turned on via the keyword argument progress=true. The progress bar updates every progress_steps timesteps, which has a default value of 1000. Note that making this value really low could cause a performance hit, though from some basic testing it seems that with updates of at least 1000 steps on number (the fastest problems), there’s no discernible performance degradation, giving a high upper bound.

Note that the progress bar also includes a time estimate. This time-estimate is provided by linear extrapolation for how long it has taken to get to what percentage. For adaptive timestepping methods this should only be used as a rough estimate since the timesteps may (and will) change. By scrolling over the progress bar, one will also see the current timestep. This can be used to track the solution’s progress and find tough locations for the solvers.

Using Progress Bars Outside Juno

To use the progress bars outside of Juno, use TerminalLoggers.jl. Follow these directions to add TerminalLogging to your startup.jl, if you want it enabled by default.

Otherwise, follow the example down below. Note that global_logger is initialized before any other Julia call. This step is crucial. Otherwise, no logging will appear in the terminal.

using Logging: global_logger
using TerminalLoggers: TerminalLogger
global_logger(TerminalLogger())

using OrdinaryDiffEq

solve(ODEProblem((u, p, t) -> (sleep(0.01); -u), 1.0, nothing),
      Euler();
      dt = 0.5,
      tspan = (0.0, 1000.0),
      progress = true,
      progress_steps = 1)