YouTube-simulations/README.md

### Tool to create videos of particles or waves in different 2D domains.

Created by **Nils Berglund** and optimized by **Marco Mancini**

C code for videos on YouTube Channel https://www.youtube.com/c/NilsBerglund

Parameter values used in specific simulations will be gradually added to file `Parameters.md`. 

There are two groups of 4 files and 5 files:

### Simulations of classical particles in billiards.

1. *global_particles.c*:    global variables and parameters
2. *sub_part_billiard.c*:   drawing/computation routines common to particle_billiard and drop_billiard
3. *particle_billiard.c*:   simulation of a collection of non-interacting particles in a billiard
4. *drop_billiard.c*:       simulation of an expanding front of particles

- Create subfolders 'tif_part', 'tif_drop'
- Customize constants at beginning of .c file
- Compile with 

gcc -o particle_billiard particle_billiard.c-O3 -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut

gcc -o drop_billiard drop_billiard.c-O3 -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut

- Many laptops claim to have 4 cores, but two of those are virtual. OMP acceleration may be more effective after executing           

export OMP_NUM_THREADS=2 

in the shell before running the program

- Generate movie with 

ffmpeg -i part.%05d.tif -vcodec libx264 part.mp4

### Simulations of wave equation, heat equation and Schrodinger equation.

1. *global_pdes.c*:     global variables and parameters
2. *sub_wave.c*:        drawing/computation routines common to wave_billiard, heat and schrodinger
3. *wave_billiard.c*:   simulation of the (linear) wave equation
4. *heat.c*:            simulation of the heat equation, with optional drawing of gradient field lines
5. *schrodinger.c*:     simulation of the Schrodinger equation

- Create subfolders 'tif_wave', 'tif_heat', 'tif_schrod'
- Customize constants at beginning of .c file
- Compile with 

gcc -o wave_billiard wave_billiard.c -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut -O3 -fopenmp

gcc -o heat heat.c -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut -O3 -fopenmp

gcc -o schrodinger schrodinger.c -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut -O3 -fopenmp

- Many laptops claim to have 4 cores, but two of those are virtual. OMP acceleration may be more effective after executing           

export OMP_NUM_THREADS=2 

in the shell before running the program

- Generate movie with 

ffmpeg -i wave.%05d.tif -vcodec libx264 wave.mp4