OHHCDF Marginal wave height, Hd, CDF for Ochi-Hubble spectra. CALL: f = ohhcdf(h,Hm0,def,dim) f = cdf 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 OHHCDF 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'. OHHCDF is restricted to the following range for Hm0: 0 < Hm0 [m] < 12, 1 <= def < 11, Example: Hm0 = 6;def = 8; h = linspace(0,4*Hm0/sqrt(2))'; f = ohhcdf(h,Hm0,def); plot(h,f) dt = 0.4; w = linspace(0,2*pi/dt,256)'; xs = spec2sdat(ohspec2(w,[Hm0, def]),6000); rate=8; method=1; [S,H] = dat2steep(xs,rate,method); empdistr(H,[h f],'g') See also ohhvpdf
Wave height, Hd, distribution parameters for Ochi-Hubble spectra. | |
Generalized Gamma cumulative distribution function | |
Display message and abort function. | |
Display warning message; disable or enable warning messages. |
001 function f = ohhcdf(h,Hm0,def,dim,norm,pdef) 002 %OHHCDF Marginal wave height, Hd, CDF for Ochi-Hubble spectra. 003 % 004 % CALL: f = ohhcdf(h,Hm0,def,dim) 005 % 006 % f = cdf 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 % OHHCDF 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 % OHHCDF is restricted to the following range for Hm0: 024 % 0 < Hm0 [m] < 12, 1 <= def < 11, 025 % 026 % Example: 027 % Hm0 = 6;def = 8; 028 % h = linspace(0,4*Hm0/sqrt(2))'; 029 % f = ohhcdf(h,Hm0,def); 030 % plot(h,f) 031 % dt = 0.4; w = linspace(0,2*pi/dt,256)'; 032 % xs = spec2sdat(ohspec2(w,[Hm0, def]),6000); rate=8; method=1; 033 % [S,H] = dat2steep(xs,rate,method); 034 % empdistr(H,[h f],'g') 035 % 036 % See also ohhvpdf 037 038 % Reference 039 % P. A. Brodtkorb (2004), 040 % The Probability of Occurrence of Dangerous Wave Situations at Sea. 041 % Dr.Ing thesis, Norwegian University of Science and Technolgy, NTNU, 042 % Trondheim, Norway. 043 044 % History 045 % revised pab jan2004 046 % By pab 20.01.2001 047 048 049 error(nargchk(2,4,nargin)) 050 051 if nargin<4|isempty(dim), dim = 'time';end 052 if nargin<3|isempty(def), def = 1;end 053 054 if Hm0>12| Hm0<=0 055 disp('Warning: Hm0 is outside the valid range') 056 disp('The validity of the Hd distribution is questionable') 057 end 058 059 if def>11|def<1 060 Warning('DEF is outside the valid range') 061 def = mod(def-1,11)+1; 062 end 063 064 Hrms = Hm0/sqrt(2); 065 [A0, B0, C0] = ohhgparfun(Hm0,def,dim); 066 f = wggamcdf(h/Hrms,A0,B0,C0); 067 return 068 %old calls 069 % pardef = 7; 070 % switch pardef 071 % case 1 072 % w = linspace(0,100,16*1024+1).'; % original spacing 073 % S = ohspec2(w,[Hm0,def]); 074 % R = spec2cov(S); 075 % % A0 = sqrt((1-min(R.R)/R.R(1))/2);% Naess (1985) 076 % A0 = sqrt((1-min(R.R)/R.R(1))/2)+0.03;% Modified approach broadbanded time 077 % % A0 = sqrt((1-min(R.R)/R.R(1))/2)+0.1;% Modified approach broadbanded space 078 079 % B0 = 2; 080 % C0 = 0; 081 % case 7, 082 % global OHHWPAR 083 % if isempty(OHHWPAR) 084 % OHHWPAR = load('thwpar.mat'); 085 % end 086 % % Truncated Weibull distribution parameters as a function of Tp, Hm0 087 % A00 = OHHWPAR.A00s; 088 % B00 = OHHWPAR.B00s; 089 % C00 = OHHWPAR.C00s; 090 091 % Hm00 = OHHWPAR.Hm0; 092 % if 1, 093 % method = '*cubic'; 094 % A0 = interp1(Hm00,A00(:,def),Hm0,method); 095 % B0 = interp1(Hm00,B00(:,def),Hm0,method); 096 % C0 = interp1(Hm00,C00(:,def),Hm0,method); 097 % else 098 % A0 = smooth(Hm00,A00(:,def),1,Hm0); 099 % B0 = smooth(Hm00,B00(:,def),1,Hm0); 100 % C0 = smooth(Hm00,C00(:,def),1,Hm0); 101 % end 102 103 % end 104 105 %Hrms = Hm0/sqrt(2); 106 %f.f = wtweibcdf(h/Hrms,A0,B0,C0)/Hrms; 107 108 return 109
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