def calc_age_max(self,ncfile,dx,dy,xlims=None,ylims=None):
# Set the xy limits
if xlims==None or ylims==None:
xlims=self.xlims
ylims=self.ylims
scalefac = 1/86400.
xp,yp,agemax = self.readAgeMax(ncfile)
grd = RegGrid(xlims,ylims,dx,dy)
agegrid = grd.griddata(xp,yp,agemax)*scalefac
return grd.X,grd.Y,agegrid
def plotAgeMax(self,ncfile,dx,dy,vmax=7,xlims=None,ylims=None,**kwargs):
"""
Filled contour plot of the maximum age of particle based on their initial locations
"""
# Set the xy limits
if xlims==None or ylims==None:
xlims=self.xlims
ylims=self.ylims
xp,yp,agemax = self.readAgeMax(ncfile)
grd = RegGrid(xlims,ylims,dx,dy)
agegrid = grd.griddata(xp,yp,agemax)*scalefac
fig=plt.gcf()
self.contourf(z=-self.dv,clevs=20,titlestr='',xlims=xlims,ylims=ylims,\
filled=False,colors='k',linestyles='solid',linewidths=0.2)
plt.pcolor(grd.X,grd.Y,agegrid,vmax=vmax,**kwargs)
plt.colorbar()
plt.title('Particle Age [days]\n(file name: %s)'%ncfile)
def calcAgeMaxProb(self,ncfiles,dx,dy,exceedance_thresh,plot=True,xlims=None,ylims=None,**kwargs):
"""
Calculate the probability of the age exceeding a threshold time from
a series of particle tracking runs.
"""
scalefac = 1/86400.
# Set the xy limits
if xlims==None or ylims==None:
xlims=self.xlims
ylims=self.ylims
# Create the probability grid
grd = RegGrid(xlims,ylims,dx,dy)
nruns = len(ncfiles)
prob = np.zeros((grd.ny,grd.nx))
# Loop through the files and add one to the probability matrix
# where the age exceeds the threshold
for ncfile in ncfiles:
print 'Reading file: %s'%ncfile
xp,yp,agemax = self.readAgeMax(ncfile)
agegrid = grd.griddata(xp,yp,agemax)
ind = agegrid >= exceedance_thresh
prob[ind] = prob[ind]+1
# Return the probability as a percentage
prob = prob/nruns*100.0
if plot:
fig=plt.gcf()
self.contourf(z=-self.dv,clevs=20,titlestr='',xlims=xlims,ylims=ylims,\
filled=False,colors='k',linestyles='solid',linewidths=0.2)
plt.pcolor(grd.X,grd.Y,prob,vmax=100,cmap=plt.cm.Spectral_r)
plt.colorbar()
plt.title('Probability (%%) of particle age exceeding %3.1f days'%(exceedance_thresh*scalefac))