From 1727b072fa9f269bcde73b516bc7b00f13fc9c99 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <51029046+JoshuaLampert@users.noreply.github.com>
Date: Wed, 11 Oct 2023 16:23:12 +0200
Subject: [PATCH] Show percentage of simulation progress (#1659)

* show percentage of simulation progress

* add notes about AnalysisCallback in docs

* generalize for general initial time

---------

Co-authored-by: Hendrik Ranocha <ranocha@users.noreply.github.com>
---
 docs/src/callbacks.md          |  5 +++++
 src/callbacks_step/alive.jl    | 10 ++++++++--
 src/callbacks_step/analysis.jl | 10 ++++++++--
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/docs/src/callbacks.md b/docs/src/callbacks.md
index 7f44dfd5925..f018bcf7c39 100644
--- a/docs/src/callbacks.md
+++ b/docs/src/callbacks.md
@@ -30,6 +30,11 @@ An example elixir using AMR can be found at [`examples/tree_2d_dgsem/elixir_adve
 The [`AnalysisCallback`](@ref) can be used to analyze the numerical solution, e.g. calculate
 errors or user-specified integrals, and print the results to the screen. The results can also be
 saved in a file. An example can be found at [`examples/tree_2d_dgsem/elixir_euler_vortex.jl`](https://github.com/trixi-framework/Trixi.jl/blob/main/examples/tree_2d_dgsem/elixir_euler_vortex.jl).
+Note that the errors (e.g. `L2 error` or `Linf error`) are computed with respect to the initial condition.
+The percentage of the simulation time refers to the ratio of the current time and the final time, i.e. it does
+not consider the maximal number of iterations. So the simulation could finish before 100% are reached.
+Note that, e.g., due to AMR or smaller time step sizes, the simulation can actually take longer than
+the percentage indicates.
 In [Performance metrics of the `AnalysisCallback`](@ref performance-metrics) you can find a detailed
 description of the different performance metrics the `AnalysisCallback` computes.
 
diff --git a/src/callbacks_step/alive.jl b/src/callbacks_step/alive.jl
index eeacd9681d8..9df7181521e 100644
--- a/src/callbacks_step/alive.jl
+++ b/src/callbacks_step/alive.jl
@@ -86,9 +86,15 @@ function (alive_callback::AliveCallback)(integrator)
         println("─"^100)
         println()
     elseif mpi_isroot()
+        t = integrator.t
+        t_initial = first(integrator.sol.prob.tspan)
+        t_final = last(integrator.sol.prob.tspan)
+        sim_time_percentage = (t - t_initial) / (t_final - t_initial) * 100
         runtime_absolute = 1.0e-9 * (time_ns() - alive_callback.start_time)
-        @printf("#timesteps: %6d │ Δt: %.4e │ sim. time: %.4e │ run time: %.4e s\n",
-                integrator.stats.naccept, integrator.dt, integrator.t, runtime_absolute)
+        println(rpad(@sprintf("#timesteps: %6d │ Δt: %.4e │ sim. time: %.4e (%5.3f%%)",
+                              integrator.stats.naccept, integrator.dt, t,
+                              sim_time_percentage), 71) *
+                @sprintf("│ run time: %.4e s", runtime_absolute))
     end
 
     # avoid re-evaluating possible FSAL stages
diff --git a/src/callbacks_step/analysis.jl b/src/callbacks_step/analysis.jl
index a3e49007fb6..e5b4a01a885 100644
--- a/src/callbacks_step/analysis.jl
+++ b/src/callbacks_step/analysis.jl
@@ -232,6 +232,12 @@ function (analysis_callback::AnalysisCallback)(u_ode, du_ode, integrator, semi)
     @unpack dt, t = integrator
     iter = integrator.stats.naccept
 
+    # Compute the percentage of the simulation that is done
+    t = integrator.t
+    t_initial = first(integrator.sol.prob.tspan)
+    t_final = last(integrator.sol.prob.tspan)
+    sim_time_percentage = (t - t_initial) / (t_final - t_initial) * 100
+
     # Record performance measurements and compute performance index (PID)
     runtime_since_last_analysis = 1.0e-9 * (time_ns() -
                                    analysis_callback.start_time_last_analysis)
@@ -291,8 +297,8 @@ function (analysis_callback::AnalysisCallback)(u_ode, du_ode, integrator, semi)
                     "               " *
                     " └── GC time:    " *
                     @sprintf("%10.8e s (%5.3f%%)", gc_time_absolute, gc_time_percentage))
-        mpi_println(" sim. time:      " * @sprintf("%10.8e", t) *
-                    "               " *
+        mpi_println(rpad(" sim. time:      " *
+                         @sprintf("%10.8e (%5.3f%%)", t, sim_time_percentage), 46) *
                     " time/DOF/rhs!:  " * @sprintf("%10.8e s", runtime_relative))
         mpi_println("                 " * "              " *
                     "               " *