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Write or plot computed quantities

For definitions of output parameters, see Appendix A.


WARNING:
When integral parameters are computed by the user from the output spectrum of SWAN, differences with the SWAN-computed parameters may occur. The reasons are:

This is particularly relevant along the boundaries of SWAN where the user-imposed integral parameters (boundary conditions) may differ from the SWAN-computed parameters. The user is informed by means of a warning in the output (PRINT file) when the computed significant wave height differs more than 10%, say, from the user-imposed significant wave height (command BOUNDSPEC). The actual value of this difference can be set by the user (see the SET command; Section 4.4).


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          | ..........|
QUANTity <             > 'short' 'long' [lexp] [hexp]  [excv]                   &
          | ..........|

     [power]               (For output quantities PER, RPER and WLEN)           &

     [ref]                 (For output quantity TSEC)                           &

     [fswell]              (For output quantity HSWELL)                         &

     [fmin] [fmax]         (For all integral parameters, like HS, (R)TM01 ...)  &

      |-> PROBLEMcoord |
     <                  >  (For directions (DIR, TDIR, PDIR)
      |   FRAME        |    and vectors (FORCE, WIND, VEL, TRANSP))

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With this command the user can influence


  |...|    
<         > the output parameters are the same as given in command BLOCK.  
  |...|    
`short' user preferred short name of the output quantity (e.g. the name appearing in  
  the heading of a table written by SWAN). If this option is not used, SWAN  
  will use a realistic name.  
`long' long name of the output quantity (e.g. the name appearing in the heading of a  
  block output written by SWAN). If this option is not used, SWAN will use a  
  realistic name.  
[lexp] lowest expected value of the output quantity.  
[hexp] highest expected value of the output quantity; the highest expected value is  
  used by SWAN to determine the number of decimals in a table with heading.  
  So the QUANTITY command can be used in case the default number of decimals  
  in a table is unsatisfactory.  
[excv] in case there is no valid value (e.g. wave height in a dry point) this  
  exception value of the output quantity is written in a table or block output.  

The following data are accepted only in combination with some specific output quantities.

[power] power $p$ appearing in the definition of PER, RPER and WLEN  
  (see Appendix A). Note that the value for [power] given for PER  
  affects also the value of RPER; the power for WLEN is independent of that  
  of PER or RPER.  
  Default: [power]=1.  
[ref] reference time used for the quantity TSEC.  
  Default value: starting time of the first computation, except in cases where  
  this is later than the time of the earliest input. In these cases, the time of  
  the earliest input is used.  
[fswell] upper limit of frequency range used for computing the quantity HSWELL  
  (see Appendix A).  
  Default: [fswell] = 0.1 Hz.  
[fmin] lower limit of frequency range used for computing integral parameters.  
  Default: [fmin] = 0.0 Hz.  
[fmax] upper limit of frequency range used for computing integral parameters.  
  Default: [fmax] = 1000.0 Hz (acts as infinity).  
PROBLEMCOORD $-$ vector components are relative to the $x-$ and $y-$axes of the problem  
  coordinate system:  
  $\bullet$ directions are counterclockwise relative to the positive $x-$axis of the  
  problem coordinate system if Cartesian direction convention is used (see  
  command SET)  
  $\bullet$ directions are relative to North (clockwise) if Nautical direction  
  convention is used (see command SET)  
FRAME If output is requested on sets created by command FRAME or automatically  
  (COMPGRID or BOTTGRID):  
  $\bullet$ vector components are relative to the $x-$ and $y-$axes of the frame  
  coordinate system  
  $\bullet$ directions are counterclockwise relative to the positive $x-$axis of the  
  frame coordinate system if Cartesian direction convention is used (see  
  command SET)  
  $\bullet$ directions are relative to North (clockwise) if Nautical direction  
  convention is used (see command SET)  

Examples:

QUANTITY Xp hexp=100. for simulations of lab. experiments  
QUANTITY HS TM01 RTMM10 excv=-9. to change the exception value for $H_s$,  
  $T_{m01}$ and relative $T_{m-10}$  
QUANTITY HS TM02 FSPR fmin=0.03 fmax=0.5 to compute $H_s$, $T_{m02}$ and frequency  
  spreading by means of integration over  
  $f \in [0.03, 0.5]$  
QUANTITY Hswell fswell=0.08 to change the value of [fswell]  
QUANTITY Per short='Tm-1,0' power=0. to redefine average wave period  
QUANTITY Transp Force Frame to obtain vector components and  
  direction with respect to the frame  


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OUTPut OPTIons 'comment' (TABle [field]) (BLOck [ndec] [len]) (SPEC [ndec])

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This command enables the user to influence the format of block, table and spectral output.


comment a comment character; is used in comment lines in the output  
  Default: comment = %  
field length of one data field in a table. Minimum is 8 and maximum is 16.  
  Default: field = 12  
ndec number of decimals in block (if appearing after keyword BLOCK) or  
  2D spectral output (if appearing after keyword SPEC). Maximum is 9.  
  Default: ndec = 4 (in both block and spectral outputs)  
len number of data on one line of block output. Maximum is 9999.  
  Default: len = 6  


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                 | -> HEADer   |
BLOck  'sname'  <               > 'fname' (LAYout [idla])
                 |    NOHEADer |

           | HSign     |
           |           |
           | HSWEll    |
           |           |
           | DIR       |
           |           |
           | PDIR      |
           |           |
           | TDIR      |
           |           |
           | TM01      |
           |           |
           | RTM01     |
           |           |
           | RTP       |
           |           |
           | TPS       |
           |           |
           | PER       |
           |           |
           | RPER      |
           |           |
           | TMM10     |
           |           |
           | RTMM10    |
           |           |
           | TM02      |
           |           |
           | FSPR      |
           |           |
           | DSPR      |
           |           |
           | QP        |
           |           |
           | DEPth     |
           |           |
           | WATLev    |
           |           |
           | BOTLev    |
           |           |
           | VEL       |
           |           |
           | FRCoef    |
           |           |
           | WIND      |
           |           |
           | AICE      |
           |           |
           | HICE      |
           |           |
           | HBIG      |
           |           |
           | PROPAgat  |
           |           |
           | PROPXy    |
           |           |
           | PROPTheta |
           |           |
           | PROPSigma |
           |           |
           | GENErat   |
           |           |
           | GENWind   |
           |           |
           | REDIst    |
           |           |
           | REDQuad   |
           |           |
           | REDTriad  |                                          | -> Sec  |
     <    <             >  [unit] > (OUTput [tbegblk] [deltblk]) <     MIn   >
           | DISSip    |                                          |    HR   |
           |           |                                          |    DAy  |
           | DISBot    |
           |           |
           | DISSUrf   |
           |           |
           | DISWcap   |
           |           |
           | DISSWell  |
           |           |
           | DISVeg    |
           |           |
           | DISMud    |
           |           |
           | DISIce    |
           |           |
           | RADStr    |
           |           |
           | QB        |
           |           |
           | GAMMA     |
           |           |
           | TRAnsp    |
           |           |
           | FORce     |
           |           |
           | UBOT      |
           |           |
           | URMS      |
           |           |
           | TMBOT     |
           |           |
           | WLENgth   |
           |           |
           | LWAVP     |
           |           |
           | STEEpness |
           |           |
           | BFI       |
           |           |
           | NPLants   |
           |           |
           | DHSign    |
           |           |
           | DRTM01    |
           |           |
           | LEAK      |
           |           |
           | TIME      |
           |           |
           | TSEC      |
           |           |
           | XP        |
           |           |
           | YP        |
           |           |
           | DIST      |
           |           |
           | SETUP     |
           |           |
           | PTHSign   |
           |           |
           | PTRTP     |
           |           |
           | PTWLEN    |
           |           |
           | PTDIR     |
           |           |
           | PTDSPR    |
           |           |
           | PTWFRAC   |
           |           |
           | PTSTEEpne |
           |           |
           | PARTITion |

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CANNOT BE USED IN 1D-MODE.


With this optional command the user indicates that one or more spatial distributions should be written to a file.


'sname' name of frame or group (see commands FRAME or GROUP)  
HEADER with this option the user indicates that the output should be written to a file  
  with header lines. The text of the header indicates run identification (see  
  command PROJECT), time, frame name or group name ('sname'), variable and  
  unit. The number of header lines is 8.  
  Note: the numerical values in the file are in the units indicated in the header.  
NOHEADER with this option the user indicates that the output should be written to a file  
  without header lines.  
'fname' name of the data file where the output is to be written to.  
  Default for option HEADER is the PRINT file. In case of NOHEADER the  
  filename is required. Below a few remarks on the file formats.  
     
  Basically, the output files generated by SWAN are human-readable files that  
  use ASCII character encoding. Such files can be open and edit in any text editor  
  or can be viewed in Matlab or Excel. However, if the user specifies the extension  
  of the output file as `.mat', a binary MATLAB file will be generated. This file  
  requires less space on your computer and can be loaded in MATLAB much faster  
  than an ASCII file. Also note that the output parameters are stored as single  
  precision. (Hence, use the Matlab command double for conversion to double  
  precision, if necessary.) Binary MATLAB files are particularly useful for the  
  computation with unstructured grids. A number of MATLAB scripts are provided  
  with the SWAN source code that can be used to plot wave parameters as maps  
  in a simple way.  
     
  Another option is to write the output to a netCDF format (Network Common  
  Data Form). The file extension must be in this case `.nc'. This format is  
  self-describing and machine independent. Moreover, it is an open standard and  
  portable. This will enhance accessibility of data exchange and also easily  
  facilitate using output from one application as input to another.  
  Like MATLAB files, storage and retrieval of netCDF files is very fast.  
     
  Since version 41.41, SWAN can generate VTK files that can be viewed in  
  Paraview, an open-source, general-purpose visualization package, available for  
  Windows, Mac and Linux (see https://www.paraview.org). The basic extension  
  is `.vtk', but SWAN will generate various XML-based file formats depending on  
  the grid types (*.vts associated with structured grids and *.vtu containing  
  unstructured mesh data). Like netCDF files, the VTK XML files are binary,  
  self-descriptive (include plain text metadata) and portable (cross-platform).  
  In addition, a key benefit is that there is no need to collect VTK files residing  
  on separate processes of a distributed memory machine (after execution of  
  SWAN in parallel). Paraview can simply visualize the whole domain that  
  consists of several subdomains.  
     
LAY-OUT with this option the user can prescribe the lay-out of the output to file with  
  the value of [idla].  
[idla] see command READINP (options are: [idla]=1, 3, 4). Option 4 is recommended  
  for postprocessing an ASCII file by MATLAB, however, in case of a generated  
  binary MATLAB file option 3 is recommended.  
  Default: [idla] = 1.  
  ONLY MEANT FOR STRUCTURED GRIDS.  

For definitions of the output quantities, see Appendix A.


Note that the wave parameters in the output of SWAN are computed from the wave spectrum over the prognostic part of the spectrum with the diagnostic tail added. Their value may therefore deviate slightly from values computed by the user from the output spectrum of SWAN which does not contain the diagnostic tail.


HSIGN significant wave height (in m).  
HSWELL swell wave height (in m).  
DIR mean wave direction (Cartesian or Nautical convention, see command SET).  
  For Cartesian convention: relative to $x-$axis of the problem coordinate system  
  (counterclockwise); possible exception: in the case of output with BLOCK  
  command in combination with command FRAME, see command QUANTITY.  
PDIR peak wave direction in degrees.  
  For Cartesian convention: relative to $x-$axis of the problem coordinate system  
  (counterclockwise); possible exception: in the case of output with BLOCK  
  command in combination with command FRAME, see command QUANTITY.  
TDIR direction of energy transport in degrees.  
  For Cartesian convention: relative to $x-$axis of the problem coordinate system  
  (counterclockwise); possible exception: in the case of output with BLOCK  
  command in combination with command FRAME, see command QUANTITY.  
TM01 mean absolute wave period (in s).  
RTM01 mean relative wave period (in s).  
RTP peak period (in s) of the variance density spectrum (relative frequency spectrum).  
TPS 'smoothed' peak period (in s).  
PER mean absolute wave period (in s).  
RPER mean relative wave period (in s).  
TMM10 mean absolute wave period (in s).  
RTMM10 mean relative wave period (in s).  
TM02 mean absolute zero-crossing period (in s).  
FSPR the normalized width of the frequency spectrum.  
DSPR directional spreading of the waves (in degrees).  
QP peakedness of the wave spectrum (dimensionless).  
DEPTH water depth (in m) (not the bottom level!).  
WATLEV water level (in m).  
  Output is in both active and non-active points.  
  Note: exception value for water levels must be given!  
  (See command INPGRID WLEVEL EXCEPTION).  
BOTLEV bottom level (in m).  
  Output is in both active and non-active points.  
  Note: exception value for bottom levels must be given!  
  (See command INPGRID BOTTOM EXCEPTION).  
VEL current velocity (vector; in m/s).  
  Relative to $x-$axis of the problem coordinate system (counterclockwise);  
  possible exception: in the case of output with BLOCK command  
  in combination with command FRAME, see command QUANTITY.  
FRCOEF friction coefficient (equal to [cfw] or [kn] in command FRICTION).  
WIND wind velocity (vector; in m/s).  
  Relative to $x-$axis of the problem coordinate system (counterclockwise);  
  possible exception: in the case of output with BLOCK command  
  in combination with command FRAME, see command QUANTITY.  
AICE ice concentration (as a fraction from 0 to 1).  
HICE ice thickness (in meters).  
HBIG bound ig wave height (in m).  
  Note: only to be specified for surfbeat (IEM) during first COMPUTE.  


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The quantities below are the contributions to the energy balance equation, containing both transport terms and source terms. These output quantities are defined as the integral over all frequencies and directions of the absolute value of each term in the equation. In this way we can estimate the associated time scale. Besides these terms we may also compute energy transfer between waves and currents due to radiation stress. Further details can be found in the ICCE paper of

Holthuijsen, L.H., Zijlema, M. and Van der Ham, P.J. (2009)
Wave physics in a tidal inlet, in: J.M. Smith (Ed.), Proc. 31st ICCE, pp. 437-448

PROPAGAT sum of PROPXY, PROPTHETA and PROPSIGMA  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
PROPXY energy propagation in geographic space; sum of $x-$ and $y-$direction  
  terms (in W/m$^2$ or m$^2$/s, depending on command SET).  
PROPTHETA energy propagation in theta space  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
PROPSIGMA energy propagation in sigma space  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
GENERAT total energy generation  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
GENWIND energy generation due to wind  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
REDIST total energy redistribution  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
REDQUAD energy redistribution due to quadruplets  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
REDTRIAD energy redistribution due to triads  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISSIP total energy dissipation  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISBOT energy dissipation due to bottom friction  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISSURF energy dissipation due to surf breaking  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISWCAP energy dissipation due to whitecapping  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISSWELL energy dissipation due to swell dissipation  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISVEG energy dissipation due to vegetation  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISMUD energy dissipation due to mud  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
DISICE energy dissipation due to sea ice  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  
RADSTR energy transfer between waves and currents due to radiation stress  
  (in W/m$^2$ or m$^2$/s, depending on command SET).  


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QB fraction of breaking waves due to depth-induced breaking.  
GAMMA breaker index derived from the beta-kd model.  
TRANSP transport of energy (vector; in W/m or m$^3$/s, depending on command SET).  
  Relative to $x-$axis of the problem coordinate system (counterclockwise);  
  possible exception: in the case of output with BLOCK command  
  in combination with command FRAME, see command QUANTITY.  
FORCE wave-induced force per unit surface area (vector; in N/m$^2$).  
  Relative to $x-$axis of the problem coordinate system (counterclockwise);  
  possible exception: in the case of output with BLOCK command  
  in combination with command FRAME, see command QUANTITY.  
UBOT the rms-value of the maxima of the orbital velocity near the bottom (in m/s).  
  Output only if command FRICTION is used. If one wants to output UBOT but  
  friction is ignored in the computation, then one should use the command  
  FRICTION with the value of the friction set to zero (FRICTION COLLINS 0).  
URMS the rms-value of the orbital velocity near the bottom (in m/s).  
  If one wants to output URMS but friction is ignored in the computation,  
  then one should use the command FRICTION with the value of the friction  
  set to zero (FRICTION COLLINS 0).  
TMBOT the bottom wave period (in s).  
WLEN average wave length (in m).  
LWAVP peak wave length (in m).  
STEEPNESS average wave steepness (dimensionless).  
BFI Benjamin-Feir index (dimensionless).  
NPLANTS number of plants per square meter.  
DHSIGN the difference in significant wave height as computed in the last two iterations.  
  This is not the difference between the computed values and the final limit of  
  the iteration process, at most an indication of this difference.  
DRTM01 the difference in average wave period (RTM01) as computed in the last two  
  iterations. This is not the difference between the computed values and the  
  final limit of the iteration process, at most an indication of this difference.  
LEAK numerical loss of energy equal to $c_{\theta} E(\omega,\theta)$ across boundaries  
  $\theta_1$ = [dir1] and $\theta_2$ = [dir2] of a directional sector (see  
  command CGRID).  
TIME Full date-time string as part of line used in TABLE only. Useful only in case of  
  nonstationary computations.  
TSEC Time in seconds with respect to a reference time (see command QUANTITY).  
  Useful only in case of nonstationary computations.  
XP user instructs SWAN to write the $x-$coordinate in the problem coordinate system  
  of the output location.  
YP user instructs SWAN to write the $y-$coordinate in the problem coordinate system  
  of the output location.  
DIST if output has been requested along a curve (see command CURVE) then the distance  
  along the curve can be obtained with the command TABLE. DIST is the distance  
  along the curve measured from the first point on the curve to the output location  
  on the curve in meters (also in the case of spherical coordinates).  
SETUP Set-up due to waves (in m).  
PTHSIGN user requests partition of the significant wave height (in m).  
  Partition of wave spectra is based on the watershed algorithm of  
  Hanson and Phillips (2001). First partition is due to wind sea and  
  the remaining partitions are the swell, from highest to lowest  
  significant wave height. There will be at most 10 partitions.  
PTRTP user requests partition of the relative peak period (in s).  
PTWLEN user requests partition of the average wave length (in m).  
PTDIR user requests partition of the peak wave direction in degrees.  
  For Cartesian convention: relative to $x-$axis of the problem coordinate system  
  (counterclockwise); possible exception: in the case of output with BLOCK  
  command in combination with command FRAME, see command QUANTITY.  
PTDSPR user requests partition of the directional spreading (in degrees).  
PTWFRAC user requests partition of the wind fraction (dimensionless).  
  This indicates the fraction of that partition that is actively being forced  
  by the wind.  
PTSTEEP user requests partition of the wave steepness (dimensionless).  
PARTIT user instructs SWAN to generate the raw spectral partition file meant  
  for wave system tracking post-processing.  
  Details on the file format and meaning of different parameters may be found in  
  http://polar.ncep.noaa.gov/waves/workshop/pdfs/  
  WW3-workshop-exercises-day4-wavetracking.pdf.  
  Note that this command should not be combined with any other parameters  
  in BLOCK, although the following parameters will be automatically included,  
  namely: coordinates, depth, wind, current, Hs, Tp, wave direction, directional  
  spreading, and wave length. Also note that PARTIT cannot be used as an  
  output parameter in TABLE.  
[unit] this controls the scaling of output. The program divides computed values by [unit]  
  before writing to file, so the user should multiply the written value by [unit] to  
  obtain the proper value.  
  Default: if HEADER is selected, value is written as a 5 position integer.  
  SWAN takes [unit] such that the largest number occurring in the block  
  can be printed.  
  If NOHEADER is selected, values are printed in floating-point format, [unit] = 1.  
OUTPUT the user requests output at various times. If the user does not use this option, the  
  program will give BLOCK output for the last time step of the computation.  
[tbegblk] begin time of the first field of the variable, the format is:  
  1 : ISO-notation 19870530.153000  
  2 : (as in HP compiler) '30$-$May$-$87 15:30:00'  
  3 : (as in Lahey compiler) 05/30/87.15:30:00  
  4 : 15:30:00  
  5 : 87/05/30 15:30:00'  
  6 : as in WAM 8705301530  
  This format is installation dependent. See Implementation Manual or ask the  
  person who installed SWAN on your computer. Default is ISO-notation.  
[deltblk] time interval between fields, the unit is indicated in the next option:  
  SEC unit seconds  
  MIN unit minutes  
  HR unit hours  
  DAY unit days  


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                 | -> HEADer   |
                 |             |
TABle  'sname'  <     NOHEADer  >  'fname'                                 &
                 |             |
                 |    INDexed  |

             | ...      |                                     | -> Sec  |
       <    <             >   > (OUTput [tbegtbl] [delttbl]  <     MIn   >)
             | ...      |                                     |    HR   |
                                                              |    DAy  |

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With this optional command the user indicates that for each location of the output location set 'sname' (see commands POINTS, CURVE, FRAME or GROUP) one or more variables should be written to a file. The keywords HEADER and NOHEADER determine the appearance of the table; the filename determines the destination of the data.


'sname' name of the set of POINTS, CURVE, FRAME or GROUP  
HEADer output is written in fixed format to file with headers giving name of variable  
  and unit per column. A disadvantage of this option is that the data are written  
  in fixed format; numbers too large to be written will be shown as: ****.  
  Number of header lines is 4.  
NOHEADer output is written in floating point format to file and has no headers; it is  
  intended primarily for processing by other programs. With some spreadsheet  
  programs, however, the HEADER option works better.  
INDexed a table on file is produced which can be used directly (without editing) as input  
  to ARCVIEW, ARCINFO, etc. The user should give two TABLE commands, one  
  to produce one file with XP and YP as output quantities, the other with HS, RTM01  
  or other output quantities, such as one wishes to process in ARCVIEW  
  or ARCINFO. The first column of each file produced by SWAN with this command  
  is the sequence number of the output point. The last line of each file is  
  the word END.  
'fname' name of the data file where the output is to be written to.  
  Default for option HEADER is output to the PRINT file. In case of NOHEADER the  
  filename is required.  
  |...|    
<         > the output parameters are the same as given in command BLOCK.  
  |...|    
OUTPUT the user requests output at various times. If the user does not use this option,  
  the program will give TABLE output for the last time step of the computation.  
[tbegtbl] begin time of the first field of the variable, the format is:  
  1 : ISO-notation 19870530.153000  
  2 : (as in HP compiler) '30$-$May$-$87 15:30:00'  
  3 : (as in Lahey compiler) 05/30/87.15:30:00  
  4 : 15:30:00  
  5 : 87/05/30 15:30:00'  
  6 : as in WAM 8705301530  
  This format is installation dependent. See Implementation Manual or ask the  
  person who installed SWAN on your computer. Default is ISO-notation.  
[delttbl] time interval between fields, the unit is indicated in the next option:  
  SEC unit seconds  
  MIN unit minutes  
  HR unit hours  
  DAY unit days  

Unless specifying (see command BLOCK), the $x-$ and $y-$components of the vectorial quantities VEL, FORCE and TRANSPORT are always given with respect to the problem coordinate system.


The number of decimals in the table varies for the output parameters; it depends on the value of [hexp], given in the command QUANTITY.


\begin{picture}(18,0.12) \thicklines \put(0,0){\line(1,0){17}} \put(0,0.1){\line(1,0){17}} \end{picture} 

                  |    SPEC1D |    | -> ABSolute |    | -> S |
SPECout  'sname' <             >  <               >  <        >  'fname' &
                  | -> SPEC2D |    |    RELative |    |    L |

                                      | -> Sec  |
         OUTput [tbegspc] [deltspc]  <     MIn   >
                                      |    HR   |
                                      |    DAy  |

\begin{picture}(18,0.12) \thicklines \put(0,0){\line(1,0){17}} \put(0,0.1){\line(1,0){17}} \end{picture}

With this optional command the user indicates that for each location of the output location set 'sname' (see commands POINTS, CURVE, FRAME or GROUP) the 1D or 2D variance / energy (see command SET) density spectrum (either the relative frequency or the absolute frequency spectrum) is to be written to a data file. The name 'fname' is required in this command.


'sname' name of the set of POINTS, CURVE, FRAME or GROUP  
SPEC2D means that 2D (frequency-direction) spectra are written to file according to the  
  format described in Appendix D. Note that this output file can be used for  
  defining boundary conditions for subsequent SWAN runs (command BOUNDSPEC).  
SPEC1D means that 1D (frequency) spectra are written to file according to the format  
  described in Appendix D. Note that this output file can be used for defining  
  boundary conditions for subsequent SWAN runs (command BOUNDSPEC).  
ABS means that spectra are computed as function of absolute frequency (i.e. the  
  frequency as measured in a fixed point).  
REL means that spectra are computed as function of relative frequency (i.e. the  
  frequency as measured when moving with the current).  
S frequencies above the infragravity frequency cut-off $f_{\rm ig}$ are taken into account.  
  Note: only relevant for surfbeat (IEM) modelling.  
L frequencies below the infragravity frequency cut-off $f_{\rm ig}$ are taken into account.  
  Note: only relevant for surfbeat (IEM) modelling.  
'fname' name of the data file where the output is written to.  
  When the extension is `.nc', a netCDF file will be generated automatically.  
OUTPUT the user requests output at various times. If the user does not use this option,  
  the program will give SPECOUT output for the last time step of the computation.  
[tbegspc] begin time of the first field of the variable, the format is:  
  1 : ISO-notation 19870530.153000  
  2 : (as in HP compiler) '30$-$May$-$87 15:30:00'  
  3 : (as in Lahey compiler) 05/30/87.15:30:00  
  4 : 15:30:00  
  5 : 87/05/30 15:30:00'  
  6 : as in WAM 8705301530  
  This format is installation dependent. See Implementation Manual or ask the  
  person who installed SWAN on your computer. Default is ISO-notation.  
[deltspc] time interval between fields, the unit is indicated in the next option:  
  SEC unit seconds  
  MIN unit minutes  
  HR unit hours  
  DAY unit days  


\begin{picture}(18,0.12) \thicklines \put(0,0){\line(1,0){17}} \put(0,0.1){\line(1,0){17}} \end{picture} 

                                                    | -> Sec  |
NESTout 'sname' 'fname' OUTput [tbegnst] [deltnst] <     MIn   >
                                                    |    HR   |
                                                    |    DAy  |

\begin{picture}(18,0.12) \thicklines \put(0,0){\line(1,0){17}} \put(0,0.1){\line(1,0){17}} \end{picture}

CANNOT BE USED IN 1D-MODE


With this optional command the user indicates that the 2D spectra along a nest boundary 'sname' (see command NGRID) should be written to a data file with name 'fname'. This name is required in this command.


'sname' name of the set of output locations, as defined in a command NGRID  
'fname' name of the data file where the output is written to. The file is structured  
  according to the description in Appendix D, i.e. also the information about the  
  location of the boundary are written to this file. SWAN will use this as a check  
  for the subsequent nested run.  
OUTPUT the user requests output at various times. If the user does not use this option,  
  the program will give NESTOUT output for the last time step of the computation.  
[tbegnst] begin time of the first field of the variable, the format is:  
  1 : ISO-notation 19870530.153000  
  2 : (as in HP compiler) '30$-$May$-$87 15:30:00'  
  3 : (as in Lahey compiler) 05/30/87.15:30:00  
  4 : 15:30:00  
  5 : 87/05/30 15:30:00'  
  6 : as in WAM 8705301530  
  This format is installation dependent. See Implementation Manual or ask the  
  person who installed SWAN on your computer. Default is ISO-notation.  
[deltnst] time interval between fields, the unit is indicated in the next option:  
  SEC unit seconds  
  MIN unit minutes  
  HR unit hours  
  DAY unit days  

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The SWAN team 2024-03-19