This is a short instruction on how to use the matlab files to create the phase planes that have lead to figure 4 in the GRL-paper by Blom, Doelman, Rietkerk Chowdhury, Ylla Arbos and Schielen.

There are three file:

(1) variables_GRL.m: This is the file that sets the variables like length, width, friction, etc of the branches. This file is called in
solve_hirano_mixed_sed_1D_GRL.m and in hirano_GRL.m

(2) solve_hirano_mixed_sed_1D_GRL.m: This is the main file, that solves the ODE and draws the trajectorie in the phase plane.The file is called with 4 arguments: H1, H2, FG1 and FG2 (the depths in branches 1 and 2, and the gravel fractions in branch 1 and 2). Note that the depths are (re)set in the function itself. 

(3) hirano_GRL.m: This file contains the vector field of the set of ODE's that is solved in Schielen and Blom (2018). This function is called in 
solve_hirano_mixed_sed_1D_GRL.m, and more specifically in the ODE45-call in that function. 

To create the figure in the GRL paper, run the code in solve_hirano_mixed_sed_1D_GRL.m twice, ones with radius 2 and once with radius 20. The radius is set in line 3 of solve_hirano_mixed_sed_1D_GRL.m and determines the radius of the (quarter of) a circel in the first quadrant, with the set of initial conditions with (0/5 Pi)/20 radians interspacing, and radius 2 or 20.
