[Tutor] pygrib issues involving wind

2017-02-28 Thread Jason Snyder 
I have a grib2 file.  You can see the components of this grib2 file below:

wgrib2 -v chart_2017022812_0057.grb2

1:0:d=2017022812:RH Relative Humidity [%]:2 m above ground:57 hour fcst:
2:227081:d=2017022812:TMAX Maximum Temperature [K]:2 m above ground:54-57
hour max fcst:
3:486870:d=2017022812:UGRD U-Component of Wind [m/s]:10 m above ground:57
hour fcst:
4:751610:d=2017022812:VGRD V-Component of Wind [m/s]:10 m above ground:57
hour fcst:
5:1009523:d=2017022812:PRATE Precipitation Rate [kg/m^2/s]:surface:54-57
hour ave fcst:


Now I am trying to use pygrib to extract the U and V wind components of
this grib2 file with the below python script:

grib = 'chart_2017022812_0057.grb2'

grbs=pygrib.open(grib)
uwind = grbs.select(name='U-component of wind')[0]
rh = grbs.select(name='Relative humidity')[0]
temp = grbs.select(name='Maximum temperature')[0]
prate = grbs.select(name='Precipitation rate')[0]

while with this script, I am able to successfully extract relative
humidity, temperature, and precipitation rate, I am having a problem
extracting the u component of wind.  I get the error:

Traceback (most recent call last):
  File "testgrib.py", line 16, in 
uwind = grbs.select(name='U-Component of wind')[0]
  File "pygrib.pyx", line 609, in pygrib.open.select (pygrib.c:6175)
ValueError: no matches found


How can I resolve this issue?
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[Tutor] grb.select for multiple times

2017-03-01 Thread Jason Snyder 
I have a grib2 file with wind data at multiple taus as shown below:

3:485167:d=2017030112:UGRD:10 m above ground:3 hour fcst:
8:1652471:d=2017030112:UGRD:10 m above ground:6 hour fcst:
13:2704909:d=2017030112:UGRD:10 m above ground:9 hour fcst:
18:3865964:d=2017030112:UGRD:10 m above ground:12 hour fcst:
23:5030535:d=2017030112:UGRD:10 m above ground:15 hour fcst:
28:6089549:d=2017030112:UGRD:10 m above ground:18 hour fcst:
33:7148742:d=2017030112:UGRD:10 m above ground:21 hour fcst:
38:8216961:d=2017030112:UGRD:10 m above ground:24 hour fcst:
43:9390488:d=2017030112:UGRD:10 m above ground:27 hour fcst:


Now what I would like to do is plot these wind values at the different taus
in a time series.  I have tried to work with the following code:

grbs=pygrib.open(grib)
uwind = grbs.select(name='10 metre U wind component')
uwnddata=uwind.values

however I am not able to from this code get a list of the uwind values over
the period of time from 3 to 27 hours at 3 hour intervals.  How can I tweak
the code to get this desired result?
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Re: [Tutor] grb.select for multiple times

2017-03-01 Thread Jason Snyder 
In the below email I want to plot the time series of the uwind values at a
specific latitude and longitude.

On Wed, Mar 1, 2017 at 6:23 PM, Jason Snyder  wrote:

> I have a grib2 file with wind data at multiple taus as shown below:
>
> 3:485167:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:3 hour
> fcst:
> 8:1652471:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:6 hour
> fcst:
> 13:2704909:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:9 hour
> fcst:
> 18:3865964:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:12 hour
> fcst:
> 23:5030535:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:15 hour
> fcst:
> 28:6089549:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:18 hour
> fcst:
> 33:7148742:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:21 hour
> fcst:
> 38:8216961:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:24 hour
> fcst:
> 43:9390488:d=2017030112 <(201)%20703-0112>:UGRD:10 m above ground:27 hour
> fcst:
>
>
> Now what I would like to do is plot these wind values at the different
> taus in a time series.  I have tried to work with the following code:
>
> grbs=pygrib.open(grib)
> uwind = grbs.select(name='10 metre U wind component')
> uwnddata=uwind.values
>
> however I am not able to from this code get a list of the uwind values
> over the period of time from 3 to 27 hours at 3 hour intervals.  How can I
> tweak the code to get this desired result?
>
>
>


-- 
Jason Snyder PhD
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[Tutor] pdf generation problem

2017-03-03 Thread Jason Snyder 
I have the following program where I am trying to generate a pdf:

  1 import matplotlib
  2 matplotlib.use('AGG')
  3 import matplotlib.pyplot as plt
  4 import matplotlib.image as image
  5 import matplotlib.gridspec as gridspec
  6 from matplotlib.backends.backend_pdf import PdfPages
  7 import numpy as np
  8
  9 np.random.seed(0)
 10
 11 x, y = np.random.randn(2, 100)
 12
 13 with PdfPages('wx_plot.pdf') as pdf:
 14   fig, (ax1,ax2) = plt.subplots(nrows=2, figsize=(8,11))
 15   gs = gridspec.GridSpec(2, 1,
 16 height_ratios=[1.5,3]
 17 )
 18   ax1 = plt.subplot(gs[0])
 19   ax1.xcorr(x, y, usevlines=True, maxlags=50, normed=True, lw=2)
 20   ax1.grid(True)
 21   ax1.axhline(0, color='black', lw=2)
 22
 23   ax2 = plt.subplot(gs[1])
 24   ax2.acorr(x, usevlines=True, normed=True, maxlags=50, lw=2)
 25   ax2.grid(True)
 26   ax2.axhline(0, color='black', lw=2)
 27   pdf.savefig('fig')
 28 pdf.close()

When I run it I get the following error:

Traceback (most recent call last):
  File "testinger.py", line 13, in 
with PdfPages('wx_plot.pdf') as pdf:
AttributeError: __exit__


What is going on here and how do I resolve this issue?
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[Tutor] Problems with matplotlib

2017-03-03 Thread Jason Snyder 
I installed the python module matplotlib on a computer and when I try to
run a program with the commands:

import matplotlib.pyplot as plt I get the following errors:

Traceback (most recent call last):
  File "new.py", line 1, in 
import matplotlib
  File "/usr/lib64/python2.7/site-packages/matplotlib/__init__.py", line
151, in 
from matplotlib.rcsetup import (defaultParams,
  File "/usr/lib64/python2.7/site-packages/matplotlib/rcsetup.py", line 20,
in 
from matplotlib.colors import is_color_like
  File "/usr/lib64/python2.7/site-packages/matplotlib/colors.py", line 54,
in 
import matplotlib.cbook as cbook
  File "/usr/lib64/python2.7/site-packages/matplotlib/cbook.py", line 32,
in 
import new
  File "/home/www/html/auroratest/new.py", line 8, in 
plt.scatter(x,y)
NameError: name 'plt' is not defined

when I try to use something like import matplotlib.image as image I get the
following errors:

Traceback (most recent call last):
  File "new.py", line 1, in 
import matplotlib.image as image
  File "/usr/lib64/python2.7/site-packages/matplotlib/__init__.py", line
151, in 
from matplotlib.rcsetup import (defaultParams,
  File "/usr/lib64/python2.7/site-packages/matplotlib/rcsetup.py", line 20,
in 
from matplotlib.colors import is_color_like
  File "/usr/lib64/python2.7/site-packages/matplotlib/colors.py", line 54,
in 
import matplotlib.cbook as cbook
  File "/usr/lib64/python2.7/site-packages/matplotlib/cbook.py", line 32,
in 
import new
  File "/home/www/html/auroratest/new.py", line 1, in 
import matplotlib.image as image
  File "/usr/lib64/python2.7/site-packages/matplotlib/image.py", line 13,
in 
from matplotlib import rcParams
ImportError: cannot import name rcParams

What is causing these errors and what specific things do I need to do to
resolve this.  I need this explained clearly in a step by step way.

Thanks,

Jason

-- 
Jason Snyder PhD
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