From 8a57ddb029534daca155b3b2e8c52135f7b58e10 Mon Sep 17 00:00:00 2001 From: James Willis <james.s.willis@durham.ac.uk> Date: Mon, 28 Nov 2016 11:48:50 +0000 Subject: [PATCH] Small updates to README for generating videos from snapshots. --- examples/CoolingHaloWithSpin/README | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/examples/CoolingHaloWithSpin/README b/examples/CoolingHaloWithSpin/README index 53564036ca..fbc0a9b351 100644 --- a/examples/CoolingHaloWithSpin/README +++ b/examples/CoolingHaloWithSpin/README @@ -1,4 +1,5 @@ - +Initial Conditions Generation +----------------------------- To make the initial conditions we distribute gas particles randomly in a cube with a side length twice that of the virial radius. The density profile of the gas is proportional to r^(-2) where r is the distance @@ -16,14 +17,31 @@ While the system is initially in hydrostatic equilibrium, the cooling of the gas and the non-zero angular momentum means that the halo will collapse into a spinning disc. +Compilation +----------- To run this example, make such that the code is compiled with either the isothermal potential or softened isothermal potential, and 'const_lambda' cooling, set in src/const.h. In the latter case, a (small) value of epsilon needs to be set in cooling.yml. 0.1 kpc should work well. +Checking Results +---------------- The plotting scripts produce a plot of the density, internal energy and radial velocity profile for each snapshot. test_energy_conservation.py shows the evolution of energy with time. These can be used to check if the example has run properly. +Generating Video +---------------- +If you want to generate a video of the simulation, the frequency of +the snaphots needs to be increased. This can be modified in cooling.yml +by changing 'delta_time' to 0.01. + +Once you have the snapshots, 'gadgetviewer' can be used to create a +series of snapshot frames. The frames can then be combined together with +'ffmpeg' to produce a video. The following command can be used: + +ffmpeg -r 20 -i frame_%05d.image.png -c:v ffv1 -qscale:v 0 movie.avi + +to produce the video. -- GitLab