def sampleAtTimesofGridB(gridA, gridB, matchformat="yyyyMMddhhmm"):
""" A function to programatically sample gridA at times of gridB, similar to idv gui but the format
decides what type type is picked.
one other application of this utility is when there are a lot of times where gui selection in
IDV becomes tedious.
"""
from visad import RealType
from visad import Gridded1DDoubleSet
from visad import FieldImpl
from visad import FunctionType
from visad import VisADException
timeSetA = GridUtil.getTimeSet(gridA)
timeSetB = GridUtil.getTimeSet(gridB)
timesA = getSampleTimesInFormat(gridA, str(matchformat))
timesB = getSampleTimesInFormat(gridB, str(matchformat))
indicesA = returnMatches(timesA, timesB)
timevalsA = timeSetA.getSamples()[0]
subsetTimeValuesA = [timevalsA[i] for i in indicesA]
newTimesA = Gridded1DDoubleSet(RealType.Time, [subsetTimeValuesA],
len(subsetTimeValuesA), None,
timeSetA.getSetUnits(), None)
subsetgridA = FieldImpl(
FunctionType(RealType.Time,
gridA.getSample(0).getType()), newTimesA)
for i in range(len(subsetTimeValuesA)):
subsetgridA.setSample(i, gridA[indicesA[i]])
return subsetgridA
def makeTimeComposite(variable, avgvariable, minvalue, maxvalue):
""" Make a time composite of grid supplied(variable) between min max ranges
of a 1d avg variable supplied.
"""
from visad import FunctionType
from visad import FieldImpl
from visad import RealType
from visad import Gridded1DDoubleSet
from visad import VisADException
from ucar.unidata.util.Misc import getAverage
timeSet = GridUtil.getTimeSet(avgvariable)
newTimeIndexList = java.util.ArrayList()
newTimeValues = []
for i in range(timeSet.getLength()):
avg = getAverage(avgvariable.getSample(i).getFloats()[0])
if minvalue < avg <= maxvalue:
newTimeIndexList.add(Integer(i))
newTimeValues.append(timeSet[i].getValue())
print(len(newTimeIndexList))
if (len(newTimeIndexList) < 1):
raise VisADException("No Matches found to make a time composite")
newTimes = Gridded1DDoubleSet(RealType.Time, [newTimeValues],
len(newTimeValues), None,
timeSet.getSetUnits(), None)
compvariable = FieldImpl(
FunctionType(RealType.Time,
variable.getSample(0).getType()), newTimes)
for i in range(len(newTimeValues)):
compvariable.setSample(i, variable[newTimeIndexList[i]])
return compvariable
def getSamplesAtTimes(grid,
year=None,
season=None,
mon=None,
day=None,
hour=None,
min=None,
sec=None,
ms=None):
""" Samples a grid at specified time periods, multiple arguments can be used in complex sampling
eg.., using hour = 5 would return all samples corresponding to 5 am, further specifing year = 2008
would give samples at 5am in year 2008
"""
from visad import RealType
from visad import Gridded1DDoubleSet
from visad import FieldImpl
from visad import FunctionType
from visad import VisADException
if (str(mon) != "None" and str(season) != "None"):
raise VisADException("One of Month or Season can be used, not both")
timeSet = GridUtil.getTimeSet(grid)
indices = getSampleTimeIndices(grid, year, season, mon, day, hour, min,
sec, ms)
timevals = timeSet.getSamples()[0]
subsetTimeValues = [timevals[i] for i in indices]
newTimes = Gridded1DDoubleSet(RealType.Time, [subsetTimeValues],
len(subsetTimeValues), None,
timeSet.getSetUnits(), None)
subsetgrid = FieldImpl(
FunctionType(RealType.Time,
grid.getSample(0).getType()), newTimes)
for i in range(len(subsetTimeValues)):
subsetgrid.setSample(i, grid[indices[i]])
return subsetgrid
def makeTimeSequence(g):
""" Merge a set of single time grids/images into a time sequence """
from visad import FunctionType, FieldImpl, Gridded1DDoubleSet, QuickSort
from jarray import array
domain = getDomainSet(g[0])
dt = getDomainType(g[0])
v=[getDomain(g[i]).indexToDouble([0,])[0][0] for i in range(len(g))]
va = array(v,'d')
index = QuickSort.sort(va)
ft=FunctionType(dt, getRangeType(g[0]))
fld=FieldImpl(ft,Gridded1DDoubleSet.create(dt,va,None,domain.getSetUnits()[0],None))
for i in range(len(g)):
fld.setSample(i,g[index[i]].getSample(0),0)
return fld
def makeTimeSequence(g):
""" Merge a set of single time grids/images into a time sequence """
from visad import FunctionType, FieldImpl, Gridded1DDoubleSet, QuickSort
from jarray import array
domain = getDomainSet(g[0])
dt = getDomainType(g[0])
v=[getDomain(g[i]).indexToDouble([0,])[0][0] for i in range(len(g))]
va = array(v,'d')
index = QuickSort.sort(va)
ft=FunctionType(dt, getRangeType(g[0]))
fld=FieldImpl(ft,Gridded1DDoubleSet.create(dt,va,None,domain.getSetUnits()[0],None))
for i in range(len(g)):
fld.setSample(i,g[index[i]].getSample(0),0)
return fld
def subsetGridTimes(gridA, gridB):
""" A function to subset gridA by times of gridB.
duplicate of another function subsetAtTimesofB
"""
timeSet = GridUtil.getTimeSet(gridB)
indices = getSampleTimeIndices(grid, year, season, mon, day, hour, min,
sec, ms)
timevals = timeSet.getSamples()[0]
subsetTimeValues = [timevals[i] for i in indices]
newTimes = Gridded1DDoubleSet(RealType.Time, [subsetTimeValues],
len(subsetTimeValues), None,
timeSet.getSetUnits(), None)
subsetgrid = FieldImpl(
FunctionType(RealType.Time,
grid.getSample(0).getType()), newTimes)
for i in range(len(subsetTimeValues)):
subsetgrid.setSample(i, grid[indices[i]])
return subsetgrid
def stdMon(grid):
""" Create monthly standard deviations from a grid of monthly data over
a period of years. The number of timesteps must be a multiple of 12.
"""
from visad import VisADException
from visad import Gridded1DDoubleSet
from visad import FunctionType
from visad import FieldImpl
from visad import RealType
timeSet = GridUtil.getTimeSet(grid)
numT = timeSet.getLength()
if (numT % 12 > 0):
raise VisADException("Number of times must be a multiple of 12")
numYears = numT / 12
days = [[0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]]
units = [Util.parseUnit("days since 0001-01-01 00:00")]
newTimes = Gridded1DDoubleSet(RealType.Time, days, 12, None, units, None)
stdev = FieldImpl(FunctionType(RealType.Time,
grid.getSample(0).getType()), newTimes)
for month in range(12):
a = GridMath.applyFunctionOverTime(grid, GridMath.FUNC_STDEV, month,
12, 0)
stdev.setSample(month, a, 0)
return stdev
def ddt(grid, timegradunit):
""" compute tendency (time derivative) using forward difference,
units of returned grid are units of grid per timegradient unit
timegradient unit can be month, day, hour, minute, seconds
"""
from visad import Real
from visad import FunctionType
from visad import FieldImpl
from visad import RealType
from visad import Gridded1DDoubleSet
from ucar.visad.data import CalendarDateTime
from visad import CommonUnit
from visad import VisADException
if (GridUtil.isTimeSequence(grid) == 1):
newTimeValues = []
timediffs = []
ts = GridUtil.getTimeSet(grid)
if (str(timegradunit).lower() in ("mon", "month", "months")):
timefactor = 86400.0 * 30
timegradunit = "month"
elif (str(timegradunit).lower() in ("day", "d", "days")):
timefactor = 86400.0
timegradunit = "day"
elif (str(timegradunit).lower() in ("hr", "hour", "hours")):
timefactor = 3600.0
timegradunit = "hr"
elif (str(timegradunit).lower() in ("m", "min", "minute", "minutes")):
timefactor = 60.0
timegradunit = "min"
elif (str(timegradunit).lower() in ("s", "sec", "second", "seconds")):
timefactor = 1.0
timegradunit = "s"
else:
raise VisADException(
"Requested time gradient unit is ambigious,use month,day,hour etc"
)
for i in range(grid.getDomainSet().getLength() - 1):
newTimeValues.append((ts[i].getValue() + ts[i + 1].getValue()) / 2)
prevtime = float(ts[i].getValue(CommonUnit.secondsSinceTheEpoch))
nexttime = float(ts[i + 1].getValue(
CommonUnit.secondsSinceTheEpoch))
timediffs.append((nexttime - prevtime) / timefactor)
newTimes = Gridded1DDoubleSet(RealType.Time, [newTimeValues],
len(newTimeValues), None,
ts.getSetUnits(), None)
ddtgrid = FieldImpl(
FunctionType(RealType.Time,
grid.getSample(0).getType()), newTimes)
for i in range(grid.getDomainSet().getLength() - 1):
diff = (grid.getSample(i + 1) - grid.getSample(i)).divide(
Real(timediffs[i]))
ddtgrid.setSample(i, diff)
unitname = str(
GridUtil.getParamType(grid).getComponent(0).getDefaultUnit())
print("[" + unitname + "]/" + str(timegradunit))
newunit = Util.parseUnit("(" + unitname + ")/" + str(timegradunit))
newType = Util.makeRealType("ddt of " + getVarName(grid), newunit)
else:
raise VisADException(
"Well, this data is not a time series, hard to do a time derivative!"
)
return GridUtil.setParamType(ddtgrid, newType, 0)
def createTimeMeans(grid, meanType="None"):
""" Create time mean of a grid at periods specified by type.
meanType can be yearly, monthly, daily, hourly, minutes, seconds
"""
from visad import Real
from visad import Gridded1DDoubleSet
from visad import FieldImpl
from visad import FunctionType
from visad import RealType
from visad import VisADException
if (str(meanType).lower() in ("year", "yr", "years", "yearly")):
searchFormat = "yyyy"
elif (str(meanType).lower() in ("mon", "month", "months", "monthly")):
searchFormat = "MM"
elif (str(meanType).lower() in ("day", "d", "days", "daily")):
searchFormat = "dd"
elif (str(meanType).lower() in ("hr", "hour", "hours", "hourly")):
searchFormat = "hh"
elif (str(meanType).lower()
in ("m", "min", "minute", "minutes", "minutely")):
searchFormat = "mm"
elif (str(meanType).lower() in ("s", "sec", "second", "seconds")):
searchFormat = "ss"
else:
raise VisADException(
"Unrecognized time mean type, use yearly or monthly etc")
alltimes = getSampleTimesInFormat(grid, searchFormat)
timeSet = GridUtil.getTimeSet(grid)
timeset = GridUtil.getTimeSet(grid).getSamples()[0]
timevalues = [i for i in timeset]
oldtime = alltimes[0]
temptime = 0
count = 0
newtimelist = []
for currt, tv, i in zip(alltimes, timevalues, range(len(alltimes))):
#values are always accumulated next time
if currt == oldtime:
#takes care of multiple times,first time,last time
temptime = temptime + tv
count = count + 1
if (i == (len(alltimes) - 1)):
newtimeval = temptime / count
newtimelist.append(newtimeval)
else:
#prev values are accumulated join to list
newtimeval = temptime / count
newtimelist.append(newtimeval)
count = 1
temptime = tv
oldtime = currt
if (i == (len(alltimes) - 1)):
newtimelist.append(temptime)
#create new time set
newTimes = Gridded1DDoubleSet(RealType.Time,
[newtimelist], len(newtimelist), None,
timeSet.getSetUnits(), None)
newdatalist = FieldImpl(
FunctionType(RealType.Time,
grid.getSample(0).getType()), newTimes)
timindices = range(len(newtimelist))
oldtime = alltimes[0]
tempdata = grid.getSample(0).multiply(Real(0.0))
count = 0
newind = 0
for currt, i in zip(alltimes, range(len(alltimes))):
#values are always accumulated next time
if currt == oldtime:
#takes care of multiple times,first time,last time
tempdata = tempdata.add(grid.getSample(i))
count = count + 1
if (i == (len(alltimes) - 1)):
newdatalist.setSample(newind, tempdata.divide(Real(count)))
newind = newind + 1
else:
#prev values are accumulated join to list
newdatalist.setSample(newind, tempdata.divide(Real(count)))
newind = newind + 1
count = 1
tempdata = grid.getSample(i)
oldtime = currt
if (i == (len(alltimes) - 1)):
newdatalist.setSample(newind, tempdata.divide(Real(count)))
newParamName = "Time Mean " + str(
Util.cleanTypeName(GridUtil.getParamType(grid)))
return newName(newdatalist, newParamName)
