def Get_SegmentAveraged_PowerSpectrum_and_RedNoise(d,
SegmentLength,
TaperingRatio,
SegmentOverlapping=False):
seg_starting_i = []
segments = []
freqs_segs = 0
psd_segs = 0
rn_segs = 0
num_segs = 0
r1_segs = [] # Lag-1 autocorrelation
if SegmentOverlapping:
jump = SegmentLength / 2
else:
jump = SegmentLength
for i in range(0, len(d), jump):
ie = i + SegmentLength
if ie <= len(d):
seg_starting_i.append(i)
seg_starting_i.append(ie)
d_i = d[i:ie].copy()
# Tapering
d_i = taper(d_i, TaperingRatio)
segments.append([range(i, ie), d_i])
# Power spectrum
freqs_i, psd_i = signal.welch(np.array(d_i),
nperseg=len(d_i),
noverlap=0,
window='boxcar')
# Red noise
r1_i = lag1_autocorrelation(d_i)
rn_i = rednoise(psd_i, len(freqs_i), r1_i)
r1_segs.append(float(r1_i))
# Collect power spectrum and red noise of each segment to average later
freqs_segs = MV2.add(freqs_i, freqs_segs)
psd_segs = MV2.add(psd_i, psd_segs)
rn_segs = MV2.add(rn_i, rn_segs)
# Count number of segments to be used for averaging
num_segs += 1
print 'segment (num)', i, ie, '(', num_segs, ')'
freqs_avg = MV2.divide(freqs_segs, num_segs)
psd_avg = MV2.divide(psd_segs, num_segs)
rn_avg = MV2.divide(rn_segs, num_segs)
r1_avg = sum(r1_segs) / float(len(r1_segs))
return segments, np.array(freqs_avg), np.array(psd_avg), np.array(
rn_avg), r1_avg
def mpd(data):
"""Monsoon precipitation intensity and annual range calculation
.. describe:: Input
* data
* Assumes climatology array with 12 times step first one January
"""
months_length = [
31., 28., 31., 30., 31., 30., 31., 31., 30., 31., 30., 31.
]
mjjas = compute_season(data, [4, 5, 6, 7, 8], months_length)
ndjfm = compute_season(data, [10, 11, 0, 1, 2], months_length)
ann = compute_season(data, list(range(12)), months_length)
annrange = MV2.subtract(mjjas, ndjfm)
lat = annrange.getAxis(0)
i, e = lat.mapInterval((-91, 0, 'con'))
if i > e: # reveresedlats
tmp = i + 1
i = e + 1
e = tmp
annrange[slice(i, e)] = -annrange[slice(i, e)]
annrange.id = data.id + "_ar"
annrange.longname = "annual range"
mpi = MV2.divide(annrange, ann)
mpi.id = data.id + "_int"
mpi.longname = "intensity"
return annrange, mpi
def sperber_metrics(d, region, debug=False):
""" d: input, 1d array of cumulative pentad time series """
# Convert accumulation to fractional accumulation; normalize by sum
d_sum = d[-1]
# Normalize
frac_accum = MV2.divide(d, d_sum)
# Stat 1: Onset
onset_index = next(i for i, v in enumerate(frac_accum) if v >= 0.2)
# Stat 2: Decay
if region == 'GoG':
decay_threshold = 0.6
else:
decay_threshold = 0.8
decay_index = next(i for i, v in enumerate(frac_accum)
if v >= decay_threshold)
# Stat 3: Slope
slope = (frac_accum[decay_index] - frac_accum[onset_index]) \
/ float(decay_index - onset_index)
# Stat 4: Duration
duration = decay_index - onset_index + 1
# Calc done, return result as dic
return {
'frac_accum': frac_accum,
'onset_index': onset_index,
'decay_index': decay_index,
'slope': slope,
'duration': duration
}
def gain_pcs_fraction(full_field, eof_pattern, pcs, debug=False):
"""
NOTE: This function is designed for getting fraction of variace obtained by
pseudo pcs
Input: (dimension x, y, t should be identical for above inputs)
- full_field (t,y,x)
- eof_pattern (y,x)
- pcs (t)
Output:
- fraction: cdms2 array but for 1 single number which is float.
Preserve cdms2 array type for netCDF recording.
fraction of explained variance
"""
# 1) Get total variacne ---
variance_total = genutil.statistics.variance(full_field, axis="t")
variance_total_area_ave = cdutil.averager(
variance_total, axis="xy", weights="weighted"
)
# 2) Get variance for pseudo pattern ---
# 2-1) Reconstruct field based on pseudo pattern
if debug:
print("from gain_pcs_fraction:")
print("full_field.shape (before grower): ", full_field.shape)
print("eof_pattern.shape (before grower): ", eof_pattern.shape)
# Extend eof_pattern (add 3rd dimension as time then copy same 2d value for all time step)
reconstructed_field = genutil.grower(full_field, eof_pattern)[
1
] # Matching dimension (add time axis)
for t in range(0, len(pcs)):
reconstructed_field[t] = MV2.multiply(reconstructed_field[t], pcs[t])
# 2-2) Get variance of reconstructed field
variance_partial = genutil.statistics.variance(reconstructed_field, axis="t")
variance_partial_area_ave = cdutil.averager(
variance_partial, axis="xy", weights="weighted"
)
# 3) Calculate fraction ---
fraction = MV2.divide(variance_partial_area_ave, variance_total_area_ave)
# debugging
if debug:
print("full_field.shape (after grower): ", full_field.shape)
print("reconstructed_field.shape: ", reconstructed_field.shape)
print("variance_partial_area_ave: ", variance_partial_area_ave)
print("variance_total_area_ave: ", variance_total_area_ave)
print("fraction: ", fraction)
print("from gain_pcs_fraction done")
# return result
return fraction
def mpd(data):
"""Monsoon precipitation intensity and annual range calculation
.. describe:: Input
* data
* Assumes climatology array with 12 times step first one January
"""
months_length = [
31.,
28.,
31.,
30.,
31.,
30.,
31.,
31.,
30.,
31.,
30.,
31.]
mjjas = compute_season(data, [4, 5, 6, 7, 8], months_length)
ndjfm = compute_season(data, [10, 11, 0, 1, 2], months_length)
ann = compute_season(data, list(range(12)), months_length)
annrange = MV2.subtract(mjjas, ndjfm)
lat = annrange.getAxis(0)
i, e = lat.mapInterval((-91, 0, 'con'))
if i > e: # reveresedlats
tmp = i + 1
i = e + 1
e = tmp
annrange[slice(i, e)] = -annrange[slice(i, e)]
annrange.id = data.id + "_ar"
annrange.longname = "annual range"
mpi = MV2.divide(annrange, ann)
mpi.id = data.id + "_int"
mpi.longname = "intensity"
return annrange, mpi
def sperber_metrics(d, region, debug=False):
""" d: input, 1d array of cumulative pentad time series """
# Convert accumulation to fractional accumulation; normalize by sum
d_sum = d[-1]
frac_accum = MV2.divide(d, d_sum)
onset_index = next(i for i, v in enumerate(frac_accum) if v >= 0.2)
if region == 'GoG':
decay_threshold = 0.6
else:
decay_threshold = 0.8
decay_index = next(i for i, v in enumerate(
frac_accum) if v >= decay_threshold)
slope = (frac_accum[decay_index] - frac_accum[onset_index]) \
/ float(decay_index - onset_index)
return {'frac_accum': frac_accum,
'onset_index': onset_index,
'decay_index': decay_index,
'slope': slope}
def normalize_by_median(stat_xy):
"""
NOTE:
Input
- stat_xy: cdms2 MV2 2D array with proper axes decorated, values to visualize.
Output
- stat_xy: stat_xy after normalized by median of each row
"""
# Get median
median = genutil.statistics.median(stat_xy, axis=1)[0]
# Match shapes
stat_xy, median = genutil.grower(stat_xy, median)
# Normalize by median value
median = np.array(median)
stat_xy_normalized = MV2.divide(MV2.subtract(stat_xy, median), median)
# Decorate axes
stat_xy_normalized.setAxisList(stat_xy.getAxisList())
stat_xy_normalized.id = stat_xy.id
stat_xy = stat_xy_normalized
return stat_xy
def sperber_metrics(d, region, debug=False):
""" d: input, 1d array of cumulative pentad time series """
# Convert accumulation to fractional accumulation; normalize by sum
d_sum = d[-1]
frac_accum = MV2.divide(d, d_sum)
onset_index = next(i for i, v in enumerate(frac_accum) if v >= 0.2)
if region == 'GoG':
decay_threshold = 0.6
else:
decay_threshold = 0.8
decay_index = next(i for i, v in enumerate(frac_accum)
if v >= decay_threshold)
slope = (frac_accum[decay_index] - frac_accum[onset_index]) \
/ float(decay_index - onset_index)
return {
'frac_accum': frac_accum,
'onset_index': onset_index,
'decay_index': decay_index,
'slope': slope
}
def mjo_metric_ewr_calculation(mip, model, exp, run, debug, plot, nc_out,
cmmGrid, degX, UnitsAdjust, inputfile, var,
startYear, endYear, segmentLength, outdir):
# Open file to read daily dataset
if debug:
print('debug: open file')
f = cdms2.open(inputfile)
d = f[var]
tim = d.getTime()
comTim = tim.asComponentTime()
# Get starting and ending year and month
if debug:
print('debug: check time')
first_time = comTim[0]
last_time = comTim[-1]
# Adjust years to consider only when continous NDJFMA is available
if first_time > cdtime.comptime(startYear, 11, 1):
startYear += 1
if last_time < cdtime.comptime(endYear, 4, 30):
endYear -= 1
# Number of grids for 2d fft input
NL = len(d.getLongitude()) # number of grid in x-axis (longitude)
if cmmGrid:
NL = int(360 / degX)
NT = segmentLength # number of time step for each segment (need to be an even number)
if debug:
endYear = startYear + 2
print('debug: startYear, endYear:', startYear, endYear)
print('debug: NL, NT:', NL, NT)
#
# Get daily climatology on each grid, then remove it to get anomaly
#
numYear = endYear - startYear
mon = 11
day = 1
# Store each year's segment in a dictionary: segment[year]
segment = {}
segment_ano = {}
daSeaCyc = MV2.zeros((NT, d.shape[1], d.shape[2]), MV2.float)
for year in range(startYear, endYear):
print(year)
segment[year] = subSliceSegment(d, year, mon, day, NT)
# units conversion
segment[year] = unit_conversion(segment[year], UnitsAdjust)
# Get climatology of daily seasonal cycle
daSeaCyc = MV2.add(MV2.divide(segment[year], float(numYear)), daSeaCyc)
# Remove daily seasonal cycle from each segment
if numYear > 1:
for year in range(startYear, endYear):
segment_ano[year] = Remove_dailySeasonalCycle(
segment[year], daSeaCyc)
#
# Space-time power spectra
#
"""
Handle each segment (i.e. each year) separately.
1. Get daily time series (3D: time and spatial 2D)
2. Meridionally average (2D: time and spatial, i.e., longitude)
3. Get anomaly by removing time mean of the segment
4. Proceed 2-D FFT to get power.
Then get multi-year averaged power after the year loop.
"""
# Define array for archiving power from each year segment
Power = np.zeros((numYear, NT + 1, NL + 1), np.float)
# Year loop for space-time spectrum calculation
if debug:
print('debug: year loop start')
for n, year in enumerate(range(startYear, endYear)):
print('chk: year:', year)
d_seg = segment_ano[year]
# Regrid: interpolation to common grid
if cmmGrid:
d_seg = interp2commonGrid(d_seg, degX, debug=debug)
# Subregion, meridional average, and remove segment time mean
d_seg_x_ano = get_daily_ano_segment(d_seg)
# Compute space-time spectrum
if debug:
print('debug: compute space-time spectrum')
Power[n, :, :] = space_time_spectrum(d_seg_x_ano)
# Multi-year averaged power
Power = np.average(Power, axis=0)
# Generates axes for the decoration
Power, ff, ss = generate_axes_and_decorate(Power, NT, NL)
# Output for wavenumber-frequency power spectra
OEE = output_power_spectra(NL, NT, Power, ff, ss)
# E/W ratio
ewr, eastPower, westPower = calculate_ewr(OEE)
print('ewr: ', ewr)
print('east power: ', eastPower)
print('west power: ', westPower)
# Output
output_filename = "{}_{}_{}_{}_{}_{}-{}".format(mip, model, exp, run,
'mjo', startYear, endYear)
if cmmGrid:
output_filename += '_cmmGrid'
# NetCDF output
if nc_out:
if not os.path.exists(outdir(output_type='diagnostic_results')):
os.makedirs(outdir(output_type='diagnostic_results'))
fout = os.path.join(outdir(output_type='diagnostic_results'),
output_filename)
write_netcdf_output(OEE, fout)
# Plot
if plot:
if not os.path.exists(outdir(output_type='graphics')):
os.makedirs(outdir(output_type='graphics'))
fout = os.path.join(outdir(output_type='graphics'), output_filename)
title = mip.upper(
) + ': ' + model + ' (' + run + ') \n' + var.capitalize(
) + ', NDJFMA ' + str(startYear) + '-' + str(endYear)
if cmmGrid:
title += ', common grid (2.5x2.5deg)'
plot_power(OEE, title, fout, ewr)
# Output to JSON
metrics_result = {}
metrics_result['east_power'] = eastPower
metrics_result['west_power'] = westPower
metrics_result['east_west_power_ratio'] = ewr
metrics_result['analysis_time_window_start_year'] = startYear
metrics_result['analysis_time_window_end_year'] = endYear
# Debug checking plot
if debug and plot:
debug_chk_plot(d_seg_x_ano, Power, OEE, segment[year], daSeaCyc,
segment_ano[year])
f.close()
return metrics_result
def model_land_only(model, model_timeseries, lf, debug=False):
# -------------------------------------------------
# Mask out over ocean grid
# - - - - - - - - - - - - - - - - - - - - - - - - -
if debug:
print('debug: plot for beforeMask start')
import vcs
x = vcs.init()
x.plot(model_timeseries)
x.png('_'.join(['test', model, 'beforeMask.png']))
print('debug: plot for beforeMask done')
# Check land fraction variable to see if it meet criteria
# (0 for ocean, 100 for land, no missing value)
lat_c = lf.getAxis(0)
lon_c = lf.getAxis(1)
lf_id = lf.id
lf = MV2.array(lf.filled(0.))
lf.setAxis(0, lat_c)
lf.setAxis(1, lon_c)
lf.id = lf_id
if float(MV2.max(lf)) == 1.:
lf = MV2.multiply(lf, 100.)
# Matching dimension
if debug:
print('debug: match dimension in model_land_only')
model_timeseries, lf_timeConst = genutil.grower(model_timeseries, lf)
# Conserve axes
time_c = model_timeseries.getAxis(0)
lat_c2 = model_timeseries.getAxis(1)
lon_c2 = model_timeseries.getAxis(2)
opt1 = False
if opt1: # Masking out partial ocean grids as well
# Mask out ocean even fractional (leave only pure ocean grid)
model_timeseries_masked = MV2.masked_where(
lf_timeConst < 100, model_timeseries)
else: # Mask out only full ocean grid & use weighting for partial ocean grid
model_timeseries_masked = MV2.masked_where(
lf_timeConst == 0, model_timeseries) # mask out pure ocean grids
if model == 'EC-EARTH':
# Mask out over 90% land grids for models those consider river as
# part of land-sea fraction. So far only 'EC-EARTH' does..
model_timeseries_masked = MV2.masked_where(
lf_timeConst < 90, model_timeseries)
lf2 = MV2.divide(lf, 100.)
model_timeseries, lf2_timeConst = genutil.grower(
model_timeseries, lf2) # Matching dimension
model_timeseries_masked = MV2.multiply(
model_timeseries_masked, lf2_timeConst) # consider land fraction like as weighting
# Make sure to have consistent axes
model_timeseries_masked.setAxis(0, time_c)
model_timeseries_masked.setAxis(1, lat_c2)
model_timeseries_masked.setAxis(2, lon_c2)
if debug:
x.clear()
x.plot(model_timeseries_masked)
x.png('_'.join(['test', model, 'afterMask.png']))
x.close()
print('debug: plot for afterMask done')
return(model_timeseries_masked)
def generate_portrait(stat_xy, imgName):
# Get median
median = genutil.statistics.median(stat_xy, axis=1)[0]
print(median)
print(median.shape)
# Match shapes
stat_xy, median = genutil.grower(stat_xy, median)
print(stat_xy.shape)
print(median.shape)
# Normalize by median value
median = np.array(median)
stat_xy_normalized = MV2.divide(MV2.subtract(stat_xy, median), median)
print(stat_xy_normalized.shape)
stat_xy_normalized.setAxisList(stat_xy.getAxisList())
#
# Plotting
#
# Set up VCS Canvas
class VCSAddonsNotebook(object):
def __init__(self, x):
self.x = x
def _repr_png_(self):
fnm = tempfile.mktemp() + ".png"
self.x.png(fnm)
encoded = base64.b64encode(open(fnm, "rb").read())
return encoded
def __call__(self):
return self
# VCS Canvas
x = vcs.init(bg=True, geometry=(2600, 800))
show = VCSAddonsNotebook(x)
# Load our "pretty" colormap
x.scriptrun(
os.path.join(sys.prefix, "share", "pmp", "graphics", 'vcs',
'portraits.scr'))
# Set up Portrait Plot
P = pcmdi_metrics.graphics.portraits.Portrait()
xax = [t + ' ' for t in stat_xy_normalized.getAxis(1)[:]]
yax = [t + ' ' for t in stat_xy_normalized.getAxis(0)[:]]
# Preprocessing step to "decorate" the axis
P.decorate(stat_xy_normalized, yax, xax)
#
# Customize
#
SET = P.PLOT_SETTINGS
# Viewport on the Canvas
SET.x1 = .05
SET.x2 = .88
SET.y1 = .25
SET.y2 = .9
# Both X (horizontal) and y (VERTICAL) ticks
# Text table
SET.tictable = vcs.createtexttable()
SET.tictable.color = "black"
# X (bottom) ticks
tictextsize = 9
# Text Orientation
SET.xticorientation = vcs.createtextorientation()
SET.xticorientation.angle = -90
SET.xticorientation.halign = "right"
SET.xticorientation.height = tictextsize
# Y (vertical) ticks
SET.yticorientation = vcs.createtextorientation()
SET.yticorientation.angle = 0
SET.yticorientation.halign = "right"
SET.yticorientation.height = tictextsize
# We can turn off the "grid"
SET.draw_mesh = "y"
# Control color for missing
SET.missing_color = "grey"
# Tics length
SET.xtic1.y1 = 0
SET.xtic1.y2 = 0
# Timestamp
SET.time_stamp = None
# Colormap
SET.colormap = "bl_to_darkred"
# level to use
SET.levels = [-.5, -.4, -.3, -.2, -.1, 0, .1, .2, .3, .4, .5]
SET.levels.insert(0, -1.e20)
SET.levels.append(1.e20)
# colors to use
SET.fillareacolors = vcs.getcolors(SET.levels,
split=0,
colors=range(16, 240))
# Plot
P.plot(stat_xy_normalized, x=x)
# Save
x.png(imgName + '.png')
#
# Annotated Plot
#
Annotated = False
if Annotated:
x.clear()
SET.values.show = True
SET.values.array = stat_xy
P.plot(stat_xy_normalized, x=x, bg=0)
x.png(imgName + '_annotated.png')
model = figfilename.split('_')[5]
run = figfilename.split('_')[7]
title = mode+', '+model+' ('+run+')'
if debug:
if run == 'r1i1p1':
PlotOn = True
else:
PlotOn = False
f = cdms2.open(ncfile)
d = f(varname_pc)
f.close()
if NormalizePCts:
d = MV2.divide(d,float(calcSTD(d)))
d_avg = cdutil.averager(d,axis='0')
print 'series mean: ', d_avg
SegmentLength = int(len(d)*SegmentLengthRatio)
freqs, psd, rn, siglevel, r1, hpf, psd_max = PowerSpectrumAnalysis(
d, SegmentLength,
TaperingRatio=TaperingRatio,
SegmentOverlapping=SegmentOverlapping,
debug=debug)
# Plot
if PlotOn_xlog:
figfile = os.path.join(outdir,mode+'_'+obs_data,figfilename+'_xlog.png')
def model_land_only(model, model_timeseries, lf, debug=False):
# -------------------------------------------------
# Mask out over ocean grid
# - - - - - - - - - - - - - - - - - - - - - - - - -
if debug:
print('debug: plot for beforeMask start')
import vcs
x = vcs.init()
x.plot(model_timeseries)
x.png('_'.join(['test', model, 'beforeMask.png']))
print('debug: plot for beforeMask done')
# Check land fraction variable to see if it meet criteria
# (0 for ocean, 100 for land, no missing value)
lat_c = lf.getAxis(0)
lon_c = lf.getAxis(1)
lf_id = lf.id
lf = MV2.array(lf.filled(0.))
lf.setAxis(0, lat_c)
lf.setAxis(1, lon_c)
lf.id = lf_id
if float(MV2.max(lf)) == 1.:
lf = MV2.multiply(lf, 100.)
# Matching dimension
if debug:
print('debug: match dimension in model_land_only')
model_timeseries, lf_timeConst = genutil.grower(model_timeseries, lf)
# Conserve axes
time_c = model_timeseries.getAxis(0)
lat_c2 = model_timeseries.getAxis(1)
lon_c2 = model_timeseries.getAxis(2)
opt1 = False
if opt1: # Masking out partial ocean grids as well
# Mask out ocean even fractional (leave only pure ocean grid)
model_timeseries_masked = MV2.masked_where(lf_timeConst < 100,
model_timeseries)
else: # Mask out only full ocean grid & use weighting for partial ocean grid
model_timeseries_masked = MV2.masked_where(
lf_timeConst == 0, model_timeseries) # mask out pure ocean grids
if model == 'EC-EARTH':
# Mask out over 90% land grids for models those consider river as
# part of land-sea fraction. So far only 'EC-EARTH' does..
model_timeseries_masked = MV2.masked_where(lf_timeConst < 90,
model_timeseries)
lf2 = MV2.divide(lf, 100.)
model_timeseries, lf2_timeConst = genutil.grower(
model_timeseries, lf2) # Matching dimension
model_timeseries_masked = MV2.multiply(
model_timeseries_masked,
lf2_timeConst) # consider land fraction like as weighting
# Make sure to have consistent axes
model_timeseries_masked.setAxis(0, time_c)
model_timeseries_masked.setAxis(1, lat_c2)
model_timeseries_masked.setAxis(2, lon_c2)
if debug:
x.clear()
x.plot(model_timeseries_masked)
x.png('_'.join(['test', model, 'afterMask.png']))
x.close()
print('debug: plot for afterMask done')
return (model_timeseries_masked)
outputVarName = ['pr']
outputUnits = ['kg m-2 s-1']
### BETTER IF THE USER DOES NOT CHANGE ANYTHING BELOW THIS LINE...
for fi in range(len(inputVarName)):
print(fi, inputVarName[fi])
inputFilePath = inputFilePathbgn + inputFilePathend
#%% Process variable (with time axis)
# Open and read input netcdf file
f = cdm.open(inputFilePath + inputFileName[fi])
dtmp = f(inputVarName[fi])
d = MV2.where(MV2.greater(dtmp, -10000.), dtmp, 1.e20)
d.missing = 1.e20
cdutil.times.setTimeBoundsMonthly(d)
d = MV2.divide(d, 86400.) # CONVERT mm/day to kg m-2 s-1
lat = d.getLatitude()
lon = d.getLongitude()
print(d.shape)
#time = d.getTime() ; # Assumes variable is named 'time', for the demo file this is named 'months'
time = d.getAxis(0)
# Rather use a file dimension-based load statement
# Deal with problematic "months since" calendar/time axis
time_bounds = time.getBounds()
# time_bounds[:,0] = time[:]
# time_bounds[:-1,1] = time[1:]
# time_bounds[-1,1] = time_bounds[-1,0]+1
#time.setBounds() #####time_bounds)
#####del(time_bounds) ; # Cleanup
for i in range(40):
yr = 1979 + i
print(fi, inputVarName[fi])
inputFilePath = inputFilePathbgn + inputFilePathend[fi]
#%% Process variable (with time axis)
# Open and read input netcdf file
f = cdm.open(inputFilePath + inputFileName[fi])
# d1 = f(inputVarName[fi], time = (cdtime.comptime(yr,0,),cdtime.comptime(yr,12)),longitude=(6,10),latitude=(6,10))
d1 = f(inputVarName[fi],
time=(cdtime.comptime(
yr,
0,
), cdtime.comptime(yr, 12)))
if inputVarName[fi] == 'z': d1 = mv.divide(d1, 9.81)
plev1 = d1.getLevel()
plev1[:] = plev1[:] * 100.
plev1 = cdm.createAxis(plev1, id='plev')
plev1.designateLevel()
plev1.axis = 'Z'
plev1.long_name = 'pressure'
plev1.positive = 'down'
plev1.realtopology = 'linear'
plev1.standard_name = 'air_pressure'
plev1.units = 'Pa'
lat = d1.getLatitude()
lon = d1.getLongitude()
# Open file ---
data_path = '/clim_obs/obs/atm/mo/psl/ERAINT/psl_ERAINT_198901-200911.nc' ## Put your file here
f = cdms.open(data_path)
# Set time period ---
start_year = 1980
end_year = 2000
start_time = cdtime.comptime(start_year)
end_time = cdtime.comptime(end_year)
# Load variable ---
d = f('psl',
time=(start_time, end_time),
longitude=(-180, 180),
latitude=(20, 90)) # Provide proper variable name
d = MV2.divide(d, 100.) # Pa to hPa
d.units = 'hPa'
# Get DJF seasonal mean time series ---
d_DJF = cdutil.DJF(d)
# EOF (take only first variance mode...) ---
solver = Eof(d_DJF, weights='area')
eof = solver.eofsAsCovariance(neofs=1)
pc = solver.pcs(npcs=1, pcscaling=1) # pcscaling=1: scaled to unit variance
# (divided by the square-root of their eigenvalue)
frac = solver.varianceFraction()
# Sign control if needed ---
eof = eof * -1
pc = pc * -1
