Dimensions, Directions, and Limits
name | description |
ndim | number of spatial dimensions (1, 2, 3) |
^D | expands to 1,..,ndim |
^ND | expands to the value of ndim |
ndir | number of vector components (1, 2, 3) |
^LIM | expands to min,max |
^L | expands to min1,min2,min3,max1,max2,max3 |
^S | expands to min1:max1,min2:max2,min3:max3 |
^T | expands to lo1:hi1,lo2:hi2,lo3:hi3 |
Differential Equations and Physical Quantities
name | description |
ps(igrid)%w | w - conservative variables |
pso(igrid)%w | w at beginning of current time step |
ps(igrid)%x | x - spatial variables |
global_time | time |
it | integer counter of temporal iterations |
qdt | the time step to be used in a subroutine/function |
Indices of variables in w array:
name | description |
rho_ | density |
e_ | energy density |
p_ | pressure (primitive form of e_, same index) |
mom(1:ndir) | momentum density |
mag(1:ndir) | magnetic field |
Coordinate system
name | description |
r_ | R direction for polar or cylindrical symmetry |
phi_ | PHI direction for polar or cylindrical symmetry |
z_ | Z direction for polar or cylindrical symmetry |
Constants
name | description |
dpi | the value of pi (double precision) |
smalldouble | a small number above machine precision |
bigdouble | a very large number |
General Tokens
name | description |
i* | index for * |
h* | i*-1 Previous index |
j* | i*+1 Next index |
n* | number of *. Usually refers to an index i*=1..n*. |
d* | difference of *, derivative of * |
grad* | spatial derivative of * |
l* | limited value |
*C | add 1/2 to spatial index/indices |
*CT | add 1/2 to temporal index |
*R | on the right |
*L | on the left |
*I | input (eg. ixI^L are the limits of useful part of input) |
*O | output (eg. ixO^L are the limits of useful part of output) |
*2 | on the power two, squared |
sqr* | square root of |
kr | Kronecker delta 3*3 tensor |
lvc | Levi-Civita 3*3*3 tensor |
q* | local variables to avoid name conflict with common ones |
usr* | user defined subroutines and parameters |
*_ | indexname, integer parameters defined for legible code |
Grid Related Tokens
name | description |
G | grid (boundary ghost cells included) |
M | mesh (without boundary layers) |
B | boundary |
nghostcells | block boundary cells width in number of cells |
volume | volume of mesh |
dvolume | volume of cell |
surface | surface of cell edge |
normal | normalized normal vector of cell surface |
I/O Related Tokens
name | description |
file | input/output files |
read | reading from parameter or data files |
save | writing into output files |
last | last occasion (e.g. for saving into file) |
*ini | file containing initial conditions |
*out | file containing full results |
head | header string in files |
unit | units for open, close, read and write statements |
unitterm | standard output |
Method Related Tokens
name | description |
type* | types (e.g. boundary, flow variables) |
par | parameters |
eq | equation |
fix | fixing certain problems (e.g. divbfix) |
error | error quantification |
err | same as error |
courant | Courant condition |
step | step in multistep methods |
advance | advancing from time t to t+dt |
advect | advecting in directions idimmin..idimmax |
advect1 | a single step of a multistep time integration in advect |
Subroutine Name Tokens
name | description |
get* | subroutine names for getting values (e.g. get_flux) |
add* | subroutine names for adding values (e.g. add_source) |
Examples
For example the variable name
ditsave = d + i + t + save
is the **d**ifference in the **i**ndices of the **t**imes between **save**s into the output files, i.e. the frequency of saving snap shots measured in time steps. Another example:
ixGhi^D = i + x + G + hi + ^D
is the highest possible indices for the coordinates for the grid for each dimensions.