For Modifying the Code¶
Defining Your own Velocity Model¶
The velocity structure is defined by the subroutine vmodel_*,
called by the module m_medium.F90. These subroutines commonly have the
input/output parameters defined in the following table.
| 変数名 | in/out | type | 説明 |
|---|---|---|---|
io_prm |
in | integer | I/O number of the input parameter file |
i0,i1 |
in | integer | Start/end indices of arrays in x-direction |
j0,j1 |
in | integer | Start/end indices of arrays in y-direction |
k0,k1 |
in | integer | Start/end indices of arrays in z-direction |
xc(i0:i1) |
in | real | x grid locations |
yc(i0:i1) |
in | real | y grid locations |
zc(i0:i1) |
in | real | z grid locations |
vcut |
in | real | Cut-off velocity |
rho(k0:k1,i0:i1,j0:j1) |
out | real | Mass density [g/cm] |
lam(k0:k1,i0:i1,j0:j1) |
out | real | Lame coefficient [g/cm] |
mu(k0:k1,i0:i1,j0:j1) |
out | real | Lame coefficient [g/cm] |
qp(k0:k1,i0:i1,j0:j1) |
out | real | |
qs(k0:k1,i0:i1,j0:j1) |
out | real | |
bddep(i0:i1,j0:j1,0:NBD) |
out | real | Discontinuity boundary depths [km] |
By creating a Fortran subroutine that
returns the medium parameters rho, lam, mu, qp and qs at locations
given in the input of the subroutines xc, yc, and zc, it is easy to
add a new velocity model.
The topography and bathymetry are automatically investigated in the
m_medium module after calling the vmodel_ast routine. To make this
investigation work properly, the medium parameter mu must be zero in
the air and ocean columns and lam must be zero in the air column.
The variables bddep(:,:,0) are assumed to be the topography, and are
used for the snapshot output. The other values of bddep(:,:,1:NBD) are
used to fit the source and/or station location to the discontinuity
depths. Providing dummy values of these functions is not necessary.
Defining Your own Source Time Function¶
The source time function is called by the source__momentrate Fortran
function in m_source.F90 based on the choice of stftype. The
definitions of the source time functions are given in
share/m_fdtool.F90. It is easy to add a new source time function here
and to add the call to the new function in the m_source module.
All of the pre-defined source time functions take two time parameters,
tbeg and trise. In the source code, they are stored in the array
variable srcprm(:). If the new source time function requires more than
three parameters, the user can expand the array srcprm(:) to store
them.
Appending New Control Parameters¶
In many Fortran modules, the first set-up is performed by subroutines
called (modulename)__setup during the first computation. Some of the
setup modules read parameters from the input parameter file. These
parameters are read by the subroutine readini, which is defined in
shared/m_readini.F90.