def LWTDWS(alpha, c, cg, c0, H):
alpha0 = None
H0 = None
errorMsg = None
deg2rad = math.pi / 180.0
arg = (c0 / c) * cmath.sin(alpha * deg2rad)
if ComplexUtil.greaterThanEqual(arg, 1):
errorMsg = "Error: Violation of assumptions for Snells Law"
return alpha0, H0, errorMsg
alpha0 = (cmath.asin(arg)) / deg2rad
ksf = cmath.sqrt(c0 / (2 * cg)) # shoaling coefficient
alphaCos = cmath.cos(alpha0 * deg2rad) / cmath.cos(alpha * deg2rad)
if ComplexUtil.lessThan(alphaCos, 0):
errorMsg = "Error: Alpha1 data out of range"
return alpha0, H0, errorMsg
krf = cmath.sqrt(alphaCos) # refraction coefficient
H0 = H / (ksf * krf)
return alpha0, H0, errorMsg
def performCalculations(self, caseInputList, caseIndex = 0):
Hmo, Tp, d = self.getCalcValues(caseInputList)
dataDict = {"Hmo": Hmo, "Tp": Tp, "d": d}
Htype = []
Htype.append(0.50) #Hmed;
Htype.append(0.66) #H1/3 (1-1/3);
Htype.append(0.90) #H1/10 (1-1/10);
Htype.append(0.99) #H1/100 (1-1/100);
Hb = ERRWAVBRK1(d, 0.9)
if Hmo >= Hb:
self.errorMsg =\
"Error: Input wave broken (Hb = %6.2f %s)" % (Hb, self.labelUnitDist)
print(self.errorMsg)
self.fileOutputWriteMain(dataDict, caseIndex)
return
L, k = WAVELEN(d, Tp, 50, self.g)
steep, maxstp = ERRSTP(Hmo, d, L)
if ComplexUtil.greaterThanEqual(steep, maxstp):
self.errorMsg =\
"Error: Input wave unstable (Max: %0.4f, [H/L] = %0.4f)" %\
(maxstp.real, steep.real)
print(self.errorMsg)
self.fileOutputWriteMain(dataDict, caseIndex)
return
dterm = d/(self.g*Tp**2)
k = 0
sum1 = 0
if dterm > 0.01:
print("Input conditions indicate Rayleigh distribution")
Hb = math.sqrt(5)*Hmo
Hinc = Hb/10000
sigma = Hmo/4
Hrms = 2*math.sqrt(2)*sigma
H = [0]
p = [0]
index = [0, 0, 0, 0]
for i in range(2, 10002):
# Rayleigh distribution
H.append(Hinc * (i - 1))
term1 = math.exp(-(H[i - 1]/Hrms)**2)
term2 = (2 * H[i - 1])/Hrms**2
p.append(term1 * term2)
sum1 = sum1 + (p[i - 1]*Hinc)
if k < 4 and sum1 > Htype[k]:
index[k] = i
k = k + 1
Hout = []
for k in range(1, 4):
sum2 = 0
Hstart = H[index[k]]
Hinc = (Hb - Hstart)/10000
pprv = p[index[k]]
Hprv = Hstart
for i in range(2, 10001):
Hnxt = Hstart + Hinc*(i - 1)
term1 = math.exp(-(Hnxt/Hrms)**2)
term2 = (2 * Hnxt)/Hrms**2
pnxt = term1 * term2
darea = 0.5*(pprv + pnxt)*Hinc # area of a trapezoid
sum2 = sum2 + (Hinc/2.0 + Hprv)*darea
pprv = pnxt
Hprv = Hnxt
Hout.append(sum2 / (1 - Htype[k])) # computing centroid (areasum = 1-Htype)
else:
Hb = d
Hinc = Hb / 100.0
print("Input conditions indicate Beta-Rayleigh distribution")
a1 = 0.00089
b1 = 0.834
a2 = 0.000098
b2 = 1.208
d1 = a1*dterm**(-b1)
if d1 > 35.0:
self.errorMsg = "Error: d/gT^2 approaching infinity"
print(self.errorMsg)
self.fileOutputWriteMain(dataDict, caseIndex)
return
Hrms = (1/math.sqrt(2))*math.exp(d1)*Hmo # root-mean-square wave height
d2 = a2 * dterm**(-b2)
if d2 > 35.0:
self.errorMsg = "Error: d/gT^2 approaching infinity"
print(self.errorMsg)
self.fileOutputWriteMain(dataDict, caseIndex)
return
Hrmsq = (1/math.sqrt(2))*math.exp(d2)*Hmo**2 # root-mean-quad wave height
# Computing alpha and beta
K1 = (Hrms / Hb)**2
K2 = (Hrmsq**2) / (Hb**4)
alpha = (K1*(K2 - K1))/(K1**2 - K2)
beta = ((1.0 - K1)*(K2 - K1))/(K1**2 - K2)
term1 = (2*sp.gamma(alpha + beta))/(sp.gamma(alpha)*sp.gamma(beta))
H = []
p = []
index = [0, 0, 0, 0]
for i in range(101):
# Beta-Rayleigh distribution
H.append(Hinc*i)
# Avoid division by zero
try:
term2 = (H[i]**(2*alpha - 1))/(Hb**(2*alpha))
except:
term2 = float('inf')
# Avoid division by zero
try:
term3 = (1.0 - (H[i]/Hb)**2)**(beta - 1.0)
except:
term3 = float('inf')
p.append(term1 * term2 * term3)
sum1 = sum1 + (p[i]*Hinc)
if k < 4 and sum1 > Htype[k]:
index[k] = i
k = k + 1
Hout = []
for k in range(1, 4):
sum2 = 0
Hstart = H[index[k]]
Hinc = (Hb - Hstart)/20
pprv = p[index[k]]
Hprv = Hstart
for i in range(1, 20):
Hnxt = Hstart + Hinc*i
term2 = (Hnxt**(2*alpha - 1))/(Hb**(2*alpha))
# Avoid division by zero
try:
term3 = (1 - (Hnxt/Hb)**2)**(beta - 1)
except:
term3 = float('inf')
pnxt = term1*term2*term3
darea = 0.5*(pprv + pnxt)*Hinc # area of a trapezoid
sum2 = sum2 + (Hinc/2.0 + Hprv)*darea
pprv = pnxt
Hprv = Hnxt
Hout.append(sum2 / (1 - Htype[k])) # computing centroid (areasum = 1-Htype)
Hmed = H[index[0]]
print("Wave heights")
print("Hrms\t\t%6.2f %s" % (Hrms, self.labelUnitDist))
print("Hmed\t\t%6.2f %s" % (Hmed, self.labelUnitDist))
print("H(1/3)\t\t%6.2f %s" % (Hout[0], self.labelUnitDist))
print("H(1/10)\t\t%6.2f %s" % (Hout[1], self.labelUnitDist))
print("H(1/100)\t%6.2f %s" % (Hout[2], self.labelUnitDist))
dataDict["Hrms"] = Hrms
dataDict["Hmed"] = Hmed
dataDict["Hout"] = Hout
self.fileOutputWriteMain(dataDict, caseIndex)
if self.isSingleCase:
self.plotDict = {"Hrms": Hrms, "Hmed": Hmed, "Hout": Hout,\
"H": H, "p": p}