OHHPDF Marginal wave height, Hd, PDF for Bimodal Ochi-Hubble spectra. CALL: f = ohhpdf(h,Hm0,def,dim) f = pdf evaluated at h. h = vectors of evaluation points. Hm0 = significant wave height [m]. def = defines the parametrization of the spectral density (default 1) 1 : The most probable spectrum (default) 2,3,...11 : gives 95% Confidence spectra dim = 'time' : Hd distribution in time (default) 'space' : Hd distribution in space OHHPDF approximates the marginal PDF of Hd, i.e., zero-downcrossing wave height, for a Gaussian process with a Bimodal Ochi-Hubble spectral density (ohspec2). The empirical parameters of the model is fitted by least squares to simulated Hd data for 24 classes of Hm0. Between 50000 and 150000 zero-downcrossing waves were simulated for each class of Hm0 in DIM=='time'. Between 50000 and 300000 zero-downcrossing waves were simulated for each class of Hm0 for DIM=='space'. OHHPDF is restricted to the following range for Hm0: 0 < Hm0 [m] < 12, 1 <= def < 11, Example: Hm0 = 6;def = 8; dim = 'time'; h = linspace(0,4*Hm0/sqrt(2))'; f = ohhpdf(h,Hm0,def,dim); plot(h,f) dt = 0.4; w = linspace(0,2*pi/dt,256)'; xs = spec2sdat(ohspec2(w,[Hm0, def]),26000); rate=8; method=1; [S,H] = dat2steep(xs,rate,method); fk = kdebin(H,'epan',[],[],.5,128); hold on, pdfplot(fk,'g'), hold off See also ohhvpdf
Wave height, Hd, distribution parameters for Ochi-Hubble spectra. | |
Generalized Gamma probability density function | |
Display message and abort function. | |
Display warning message; disable or enable warning messages. |
001 function f = ohhpdf(h,Hm0,def,dim) 002 %OHHPDF Marginal wave height, Hd, PDF for Bimodal Ochi-Hubble spectra. 003 % 004 % CALL: f = ohhpdf(h,Hm0,def,dim) 005 % 006 % f = pdf evaluated at h. 007 % h = vectors of evaluation points. 008 % Hm0 = significant wave height [m]. 009 % def = defines the parametrization of the spectral density (default 1) 010 % 1 : The most probable spectrum (default) 011 % 2,3,...11 : gives 95% Confidence spectra 012 % dim = 'time' : Hd distribution in time (default) 013 % 'space' : Hd distribution in space 014 % 015 % OHHPDF approximates the marginal PDF of Hd, i.e., 016 % zero-downcrossing wave height, for a Gaussian process with a Bimodal 017 % Ochi-Hubble spectral density (ohspec2). The empirical parameters of 018 % the model is fitted by least squares to simulated Hd data for 24 019 % classes of Hm0. Between 50000 and 150000 zero-downcrossing waves were 020 % simulated for each class of Hm0 in DIM=='time'. 021 % Between 50000 and 300000 zero-downcrossing waves were 022 % simulated for each class of Hm0 for DIM=='space'. 023 % OHHPDF is restricted to the following range for Hm0: 024 % 0 < Hm0 [m] < 12, 1 <= def < 11, 025 % 026 % Example: 027 % Hm0 = 6;def = 8; dim = 'time'; 028 % h = linspace(0,4*Hm0/sqrt(2))'; 029 % f = ohhpdf(h,Hm0,def,dim); 030 % plot(h,f) 031 % dt = 0.4; w = linspace(0,2*pi/dt,256)'; 032 % xs = spec2sdat(ohspec2(w,[Hm0, def]),26000); rate=8; method=1; 033 % [S,H] = dat2steep(xs,rate,method); 034 % fk = kdebin(H,'epan',[],[],.5,128); 035 % hold on, pdfplot(fk,'g'), hold off 036 % 037 % See also ohhvpdf 038 039 040 % Reference 041 % P. A. Brodtkorb (2004), 042 % The Probability of Occurrence of Dangerous Wave Situations at Sea. 043 % Dr.Ing thesis, Norwegian University of Science and Technolgy, NTNU, 044 % Trondheim, Norway. 045 046 % History 047 % revised pab Jan 2004 048 % By pab 20.01.2001 049 050 051 error(nargchk(2,4,nargin)) 052 053 if nargin<4|isempty(dim), dim = 'time';end 054 if nargin<3|isempty(def), def = 1;end 055 056 if Hm0>12| Hm0<=0 057 disp('Warning: Hm0 is outside the valid range') 058 disp('The validity of the Hd distribution is questionable') 059 end 060 061 if def>11|def<1 062 Warning('DEF is outside the valid range') 063 def = mod(def-1,11)+1; 064 end 065 066 Hrms = Hm0/sqrt(2); 067 068 [A0 B0 C0] = ohhgparfun(Hm0,def,dim); 069 f = wggampdf(h/Hrms,A0,B0,C0)/Hrms; 070 return 071 072
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