write_velocity_field_json.m File Reference

Functions
	fwrite (fid, str, 'char')
	fclose (fid)

Variables
Create input files in JSON format for use with the quadgrid library properties of the grid	hx = hy = 0.025
	nx = ny = 2/hx
in	grid_properties = struct ('hx', hx, 'hy', hy, 'nx', nx, 'ny', ny)
	num_global_nodes = (in.grid_properties.nx+1)*(in.grid_properties.ny+1)
compute arrays to be used to define fields on the grid	x = 0 : hx : nx*hx
as we want to compute the velocity field	y = 0 : hy : ny*hy
as a function of the	coordinates
as a function of the we need to compute the coordinates	here
as a function of the we need to compute the coordinates they need not be saved in the JSON file	though [x, y] = meshgrid (x, y)
the ordering in quadgrid is explicitely intended to be compatible to that in Matlab Octave	vx = 1e-3*(2*pi*(1-y))(:)
grid arrays must be flattened	vy = 1e-3*(2*pi*(x-1))(:)
in	grid_vars = struct ('vx', vx, 'vy', vy, 'rho', zeros(num_global_nodes, 1))
generate particles and assign position and properties in	num_particles = 2.e5
in iprops	label = [0:numel(in.x)](:)
in	dprops
grid and particles are read separately but can be stored in the same file	str = jsonencode (in)
	fid = fopen ('velocity.json', 'w')

Function Documentation

fclose()

fclose

(

fid

)

fwrite()

fwrite	(	fid	,
		str	,
		'char'	)

Variable Documentation

coordinates

as a function of the coordinates

dprops

in dprops

Initial value:

= struct ('M',  2*pi*(.2/6)^2*ones(in.num_particles, 1)/in.num_particles,
            'VX', zeros(in.num_particles, 1), 'VY', zeros(in.num_particles, 1))

fid

fid = fopen ('velocity.json', 'w')

grid_properties

in grid_properties = struct ('hx', hx, 'hy', hy, 'nx', nx, 'ny', ny)

grid_vars

in grid_vars = struct ('vx', vx, 'vy', vy, 'rho', zeros(num_global_nodes, 1))

here

as a function of the we need to compute the coordinates here

hx

Create input files in JSON format for use with the quadgrid library properties of the grid hx = hy = 0.025

label

in iprops label = [0:numel(in.x)](:)

num_global_nodes

num_global_nodes = (in.grid_properties.nx+1)*(in.grid_properties.ny+1)

num_particles

generate particles and assign position and properties in num_particles = 2.e5

nx

nx = ny = 2/hx

str

grid and particles are read separately but can be stored in the same file str = jsonencode (in)

though

as a function of the we need to compute the coordinates they need not be saved in the JSON file though[x, y] = meshgrid (x, y)

vx

the ordering in quadgrid is explicitely intended to be compatible to that in Matlab Octave vx = 1e-3*(2*pi*(1-y))(:)

vy

grid arrays must be flattened vy = 1e-3*(2*pi*(x-1))(:)

x

in x = 0 : hx : nx*hx

y

in y = 0 : hy : ny*hy