scientimate.swandepthgrid#

swandepth, swangrid, ncellx, ncelly, ngridx, ngridy = scientimate.swandepthgrid(xgrid, ygrid, zgrid, zmin=None, zmax=None, nanreplacement='no', savedata='no', xyoutfilename='swangrid.xy', zoutfilename='swandepth.dep', outfilelocation=None, dispout='no')

Description#

Generate SWAN depth file and its associated x-y grid file

Inputs#

xgrid: x (longitude) of grid points as a [M*N] array
ygrid: y (latitude) of grid points as a [M*N] array
zgrid: z (elevation) of grid points as a [M*N] array

z>0 is land, z<0 is water, z=0 is water surface
zmin=nanmin(zgrid): Minimum z (elevation) to be considered

All z<zmin would be set to NaN
zmax=nanmax(zgrid): Maximum z (elevation) to be considered

All z>zmax would be set to NaN

Example: to remove all land values from z data, set zmax=0
nanreplacement=’no’: Replace NaN values with nanreplacement

By seting up an exception value equal to nanreplacement in SWAN input file, SWAN disregards these data points

If nanreplacement=’no’, then it does not replace NaN values

Example, nanreplacement=-999 will replace all NaN values with -999

Then if -999 is set as an exception in SWAN input file, SWAN disregards all -999 values
savedata=’no’: Define if save data in a file or not

‘no’: does not save

‘yes’: save data as ascii file
xyoutfilename=’swangrid.xy’: Name of output grid file between ‘ ‘ mark, example: ‘swangrid.xy’

xyoutfilename should have ‘.xy’ extension
zoutfilename=’swandepth.dep’: Name of output depth file between ‘ ‘ mark, example: ‘swandepth.dep’

zoutfilename should have ‘.dep’ extension
outfilelocation=pwd: Location of output file between ‘ ‘ mark, example: ‘C:' in MATLAB, or ‘C:/’ in Python
dispout=’no’: Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

swandepth: Depth data formated for SWAN

Note: SWAN (Delft3D) needs depth data not bathymetry data.

It means value below water surface should be positive and above surface negative.

Note: All NaN values are replaced with nanreplacement

Set up an exception value equal to nanreplacement in SWAN to disregard these data points
swangrid: Grid data formated for SWAN
ncellx: Number of cells in x direction (ncellx=ngridx-1)

In SWAN, ncellx is equal to a number of meshes in computational grid in x direction
ncelly: Number of cells in y direction (ncelly=ngridy-1)

In SWAN, ncelly is equal to a number of meshes in computational grid in y direction
ngridx: Number of grid points in x direction
ngridy: Number of grid points in y direction

Examples#

import scientimate as sm
import numpy as np
import scipy as sp
from scipy import interpolate

x=10.*np.random.rand(1000)
y=10*np.random.rand(1000)
z=x**2+y**2-np.mean(x**2+y**2)
xgrid,ygrid=np.meshgrid(np.linspace(np.min(x),np.max(x),100),np.linspace(np.min(y),np.max(y),100))
zgrid=sp.interpolate.griddata((x,y),z,(xgrid,ygrid))
zmin=np.nanmin(zgrid)
zmax=np.nanmax(zgrid)
nanreplacement=-999
savedata='no'
xyoutfilename='swangrid.xy'
zoutfilename='swandepth.dep'
outfilelocation=None
swandepth,swangrid,ncellx,ncelly,ngridx,ngridy=sm.swandepthgrid(xgrid,ygrid,zgrid,zmin,zmax,nanreplacement,savedata,xyoutfilename,zoutfilename,outfilelocation,'yes')

References#

Booij, N. R. R. C., Ris, R. C., & Holthuijsen, L. H. (1999). A third‐generation wave model for coastal regions: 1. Model description and validation. Journal of geophysical research: Oceans, 104(C4), 7649-7666.

SWAN Team. (2007). S WAN user manual. Delft University of Technology. The Netherlands.

scientimate.swandepthgrid

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