Index: /proj/ice/larour/issm-uci-clean/trunk-jpl/src/m/utils/Meca/paterson.py =================================================================== --- /proj/ice/larour/issm-uci-clean/trunk-jpl/src/m/utils/Meca/paterson.py (revision 0) +++ /proj/ice/larour/issm-uci-clean/trunk-jpl/src/m/utils/Meca/paterson.py (revision 12126) @@ -0,0 +1,50 @@ +from numpy import * + +def paterson(temperature): + + # Local Variables: pos11, pos5, pos10, temperature, pos, T, pos8, pos9, pos6, pos7, pos4, rigidity, pos2, pos3, pos1 + # Function calls: length, zeros, argwhere, paterson, error + #PATERSON - figure out the rigidity of ice for a given temperature + # + # rigidigty (in s^(1/3)Pa) is the flow law paramter in the flow law sigma=B*e(1/3) (Paterson, p97). + # temperature is in Kelvin degrees + # + # Usage: + # rigidity=paterson(temperature) + + pos=argwhere(temperature<0.) + if len(pos): + print 'input temperature should be in Kelvin (positive)' + return [] + + T = temperature-273.15 + #The routine below is equivalent to: + # n=3; T=temperature-273; + # %From paterson, + # Temp=[0;-2;-5;-10;-15;-20;-25;-30;-35;-40;-45;-50]; + # A=[6.8*10^-15;2.4*10^-15;1.6*10^-15;4.9*10^-16;2.9*10^-16;1.7*10^-16;9.4* + # 10^-17;5.1*10^-17;2.7*10^-17;1.4*10^-17;7.3*10^-18;3.6*10^-18];;%s-1(kPa-3) + # %Convert into rigidity B + # B=A.^(-1/n)*10^3; %s^(1/3)Pa + # %Now, do a cubic fit between Temp and B: + # fittedmodel=fit(Temp,B,'cubicspline'); + # rigidity=fittedmodel(temperature); + + rigidity=zeros(len(T)) + pos1=argwhere(T<=-45); rigidity[pos1]=10**8*(-0.000292866376675*(T[pos1]+50)**3+ 0.011672640664130*(T[pos1]+50)**2 -0.325004442485481*(T[pos1]+50)+ 6.524779401948101) + pos2=argwhere(logical_and(-45<=T,T<-40)); rigidity[pos2]=10**8*(-0.000292866376675*(T[pos2]+45)**3+ 0.007279645014004*(T[pos2]+45)**2 -0.230243014094813*(T[pos2]+45)+ 5.154964909039554) + pos3=argwhere(logical_and(-40<=T,T<-35)); rigidity[pos3]=10**8*(0.000072737147457*(T[pos3]+40)**3+ 0.002886649363879*(T[pos3]+40)**2 -0.179411542205399*(T[pos3]+40)+ 4.149132666831214) + pos4=argwhere(logical_and(-35<=T,T<-30)); rigidity[pos4]=10**8*(-0.000086144770023*(T[pos4]+35)**3+ 0.003977706575736*(T[pos4]+35)**2 -0.145089762507325*(T[pos4]+35)+ 3.333333333333331) + pos5=argwhere(logical_and(-30<=T,T<-25)); rigidity[pos5]=10**8*(-0.000043984685769*(T[pos5]+30)**3+ 0.002685535025386*(T[pos5]+30)**2 -0.111773554501713*(T[pos5]+30)+ 2.696559088937191) + pos6=argwhere(logical_and(-25<=T,T<-20)); rigidity[pos6]=10**8*(-0.000029799523463*(T[pos6]+25)**3+ 0.002025764738854*(T[pos6]+25)**2 -0.088217055680511*(T[pos6]+25)+ 2.199331606342181) + pos7=argwhere(logical_and(-20<=T,T<-15)); rigidity[pos7]=10**8*(0.000136920904777*(T[pos7]+20)**3+ 0.001578771886910*(T[pos7]+20)**2 -0.070194372551690*(T[pos7]+20)+ 1.805165505978111) + pos8=argwhere(logical_and(-15<=T,T<-10)); rigidity[pos8]=10**8*(-0.000899763781026*(T[pos8]+15)**3+ 0.003632585458564*(T[pos8]+15)**2 -0.044137585824322*(T[pos8]+15)+ 1.510778053489523) + pos9=argwhere(logical_and(-10<=T,T<-5)); rigidity[pos9]=10**8*(0.001676964325070*(T[pos9]+10)**3- 0.009863871256831*(T[pos9]+10)**2 -0.075294014815659*(T[pos9]+10)+ 1.268434288203714) + pos10=argwhere(logical_and(-5<=T,T<-2)); rigidity[pos10]=10**8*(-0.003748937622487*(T[pos10]+5)**3+0.015290593619213*(T[pos10]+5)**2 -0.048160403003748*(T[pos10]+5)+ 0.854987973338348) + pos11=argwhere(-2<=T); rigidity[pos11]=10**8*(-0.003748937622488*(T[pos11]+2)**3-0.018449844983174*(T[pos11]+2)**2 -0.057638157095631*(T[pos11]+2)+ 0.746900791092860) + + #Now make sure that rigidity is positive + pos=argwhere(rigidity<0); rigidity[pos]=1**6 + + return rigidity +