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datastructures

PURPOSE ^

of spectrum, covariance function and density (pdf) in WAFO

SYNOPSIS ^

This is a script file.

DESCRIPTION ^

 DATASTRUCTURES of spectrum, covariance function and density (pdf) in WAFO
 
  To represent spectra, covariance functions and probability density functions
  in WAFO, the MATLAB datatype 'structured array' is used. Here follows a list
  of the fields in the struct representing S, cvf and pdf, respectively.
 
  Spectrum structure
  ~~~~~~~~~~~~~~~~~~
   Requisite fields:
    .type  String: 'freq', 'dir', 'k2d', k1d', 'encdir' or 'enc'.
    .S     Spectrum values (size=[nf 1] or [np nf]).
    .w OR .f OR .k Frequency/wave number lag, length nf.
    .tr    Transformation function (default [] (none)). 
    .h     Water depth (default inf).
    .norm  Normalization flag, Logical 1 if S is normalized, 0 if not
    .note  Memorandum string.
    .date  Date and time of creation or change.
   Type-specific fields:
    .k2    Second dim. wave number lag, if .type='k2d' or 'rotk2d', length np.
    .theta Angular lags, if .type='dir', 'rotdir' or 'encdir', length np.
    .v     Ship speed, if .type = 'enc' or 'encdir'.
    .phi   angle of rotation of the coordinate system
           (counter-clocwise) e.g. azymuth of a ship.
 
  See also  createspec, wspecplot
 
  Covariance function (cvf) structure
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    .R Covariance function values. Size [ny nx nt], all singleton dim. removed.
    .x     Lag of first space dimension, length nx.
    .y     Lag of second space dimension, length ny.
    .t     Time lag, length nt.
    .h     Water depth.
    .tr    Transformation function.
    .type  'enc', 'rot' or 'none'.
    .v     Ship speed, if .type='enc'
    .phi   Rotation of coordinate system, e.g.  direction of ship 
    .norm  Normalization flag, Logical 1 if autocorrelation, 0 if covariance.
    .Rx ... .Rtttt   Obvious derivatives of .R.
    .note  Memorandum string.
    .date  Date and time of creation or change.
 
  See also  createcov, spec2cov, cov2spec, covplot
 
  Probability density function (pdf) structure
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  Describing a density of n variables:
    .f     Probability density function values (n-dimensional matrix)
    .x     Cell array of vectors defining grid for variables (n cells)
    .labx  Cell array of label strings for the variables (n cells)
    .title Title string                           
    .note  Memorandum string.
 
  See also  createpdf, pdfplot

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

001 %DATASTRUCTURES of spectrum, covariance function and density (pdf) in WAFO
002 %
003 % To represent spectra, covariance functions and probability density functions
004 % in WAFO, the MATLAB datatype 'structured array' is used. Here follows a list
005 % of the fields in the struct representing S, cvf and pdf, respectively.
006 %
007 % Spectrum structure
008 % ~~~~~~~~~~~~~~~~~~
009 %  Requisite fields:
010 %   .type  String: 'freq', 'dir', 'k2d', k1d', 'encdir' or 'enc'.
011 %   .S     Spectrum values (size=[nf 1] or [np nf]).
012 %   .w OR .f OR .k Frequency/wave number lag, length nf.
013 %   .tr    Transformation function (default [] (none)). 
014 %   .h     Water depth (default inf).
015 %   .norm  Normalization flag, Logical 1 if S is normalized, 0 if not
016 %   .note  Memorandum string.
017 %   .date  Date and time of creation or change.
018 %  Type-specific fields:
019 %   .k2    Second dim. wave number lag, if .type='k2d' or 'rotk2d', length np.
020 %   .theta Angular lags, if .type='dir', 'rotdir' or 'encdir', length np.
021 %   .v     Ship speed, if .type = 'enc' or 'encdir'.
022 %   .phi   angle of rotation of the coordinate system
023 %          (counter-clocwise) e.g. azymuth of a ship.
024 %
025 % See also  createspec, wspecplot
026 %
027 % Covariance function (cvf) structure
028 % ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
029 %   .R Covariance function values. Size [ny nx nt], all singleton dim. removed.
030 %   .x     Lag of first space dimension, length nx.
031 %   .y     Lag of second space dimension, length ny.
032 %   .t     Time lag, length nt.
033 %   .h     Water depth.
034 %   .tr    Transformation function.
035 %   .type  'enc', 'rot' or 'none'.
036 %   .v     Ship speed, if .type='enc'
037 %   .phi   Rotation of coordinate system, e.g.  direction of ship 
038 %   .norm  Normalization flag, Logical 1 if autocorrelation, 0 if covariance.
039 %   .Rx ... .Rtttt   Obvious derivatives of .R.
040 %   .note  Memorandum string.
041 %   .date  Date and time of creation or change.
042 %
043 % See also  createcov, spec2cov, cov2spec, covplot
044 %
045 % Probability density function (pdf) structure
046 % ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
047 % Describing a density of n variables:
048 %   .f     Probability density function values (n-dimensional matrix)
049 %   .x     Cell array of vectors defining grid for variables (n cells)
050 %   .labx  Cell array of label strings for the variables (n cells)
051 %   .title Title string                           
052 %   .note  Memorandum string.
053 %
054 % See also  createpdf, pdfplot
055 
056 % History: 
057 % revised by IR 03.04.2001
058 % revised pab 21.01.2000 
059 %  - spellchecked the file 
060 %  - added norm to spec
061 %  - changed reference to specplot to wspecplot
062 % revised by es 20.10.1999 (cell arrays in pdf-struct)
063 %          by es 13.10.1999
064 more on
065 help datastructures
066 more off
067 
068

Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

Comments or corrections to the WAFO group


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