[Tutor] loop through hours to calc max and plot

[questions anon]

Hi All,
I have monthly netcdf files containing hourly temperature data.
I would like to loop through all of the hours and calculate the max for
each hour (00 - 23) and then make a plot.
I have found a way for this to work for a couple of the hours (see below)
but it requires a lot of set up to do each hour and I am sure there must be
a simpler way using loops? I also need to find a simpler way as I would
like to eventually do daily for 1st jan to 31st Dec
Any feedback will be greatly appreciated

 from netCDF4 import Dataset

import numpy as N

import matplotlib.pyplot as plt

from numpy import ma as ma

from mpl_toolkits.basemap import Basemap

from netcdftime import utime

from datetime import datetime

import os

from matplotlib.collections import LineCollection



shapefile1="---"

OutputFolder=r"/---/"

fileforlatlon=Dataset("---.nc", 'r+', 'NETCDF4')

LAT=fileforlatlon.variables['latitude'][:]

LON=fileforlatlon.variables['longitude'][:]

#Set up basemap using mercator projection
http://matplotlib.sourceforge.net/basemap/doc/html/users/merc.html

map =
Basemap(projection='merc',llcrnrlat=-40,urcrnrlat=-33,llcrnrlon=139.0,urcrnrlon=151.0,lat_ts=0,resolution='i')

x,y=map(*N.meshgrid(LON,LAT))

map.readshapefile(shapefile1, '-REGIONS')

ncvariablename='T_SFC'

MainFolder=r"/---/"

ticks=[-5,0,5,10,15,20,25,30,35,40,45,50]

Title='Surface Temperature (degrees celsius)'

cmap=plt.cm.jet

  all_variabledata=[]

time00=[]

time12=[]



for (path, dirs, files) in os.walk(MainFolder):

for dir in dirs:

print "the dirs are:", dir

path=path+'/'

for ncfile in files:

fileext=ncvariablename+'.nc'

if ncfile.endswith(fileext):

print "dealing with ncfiles:", path+ncfile

ncfile=os.path.join(path,ncfile)

ncfile=Dataset(ncfile, 'r+', 'NETCDF4')

 TIME=ncfile.variables['time'][1::]

#variable=ncfile.variables[ncvariablename][:,:,:]

TSFC00=ncfile.variables[ncvariablename][00:01:,:,:]

TSFC12=ncfile.variables[ncvariablename][12:13:,:,:]

fillvalue=ncfile.variables[ncvariablename]._FillValue

ncfile.close()

#combine all data from the chosen variable to make one array for analyses


 cdftime=utime('seconds since 1970-01-01 00:00:00')

ncfiletime=cdftime.num2date(TIME)

for i in ncfiletime[:]:

ncfiletime=i

timestr=str(ncfiletime)

d = datetime.strptime(timestr, '%Y-%m-%d %H:%M:%S')

date_string = d.strftime('%H')#combine by same hour

print "the ncfiletime is:", ncfiletime

print "the date_string is:", date_string

if date_string=='00':

time00.append(TSFC00)

elif date_string=='12':

time12.append(TSFC12)

else:

pass

   big_arraytime00=N.ma.concatenate(time00)

big_arraytime12=N.ma.concatenate(time12)

MAX00=big_arraytime00.max(axis=0)

MAX12=big_arraytime12.max(axis=0)



#plot output summary stats

map = Basemap(projection='merc',llcrnrlat=-40,urcrnrlat=-33,

llcrnrlon=139.0,urcrnrlon=151.0,lat_ts=0,resolution='i')

map.drawcoastlines()

map.drawstates()

map.readshapefile(shapefile1, 'REGIONS')

x,y=map(*N.meshgrid(LON,LAT))

plottitle='TSFCmax00'

plt.title(plottitle)

CS = map.contourf(x,y,MAX00, ticks, cmap=cmap)

l,b,w,h =0.1,0.1,0.8,0.8

cax = plt.axes([l+w+0.025, b, 0.025, h])

plt.colorbar(CS,cax=cax, drawedges=True)

plt.savefig((os.path.join(OutputFolder, plottitle+'.png')))

plt.show()

plt.close()


map = Basemap(projection='merc',llcrnrlat=-40,urcrnrlat=-33,

llcrnrlon=139.0,urcrnrlon=151.0,lat_ts=0,resolution='i')

map.drawcoastlines()

map.drawstates()

map.readshapefile(shapefile1, 'REGIONS')


x,y=map(*N.meshgrid(LON,LAT))

plottitle='TSFCmax12'

plt.title(plottitle)

CS = map.contourf(x,y,MAX12, ticks, cmap=cmap)

l,b,w,h =0.1,0.1,0.8,0.8

cax = plt.axes([l+w+0.025, b, 0.025, h])

plt.colorbar(CS,cax=cax, drawedges=True)

plt.savefig((os.path.join(OutputFolder, plottitle+'.png')))

plt.show()

plt.close()
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20140319/090cb14c/attachment-0001.html>