.ix indexer should be changed to .loc in parameters.py

[sum1lim]

.ix is deprecated since pandas 0.20.0 version release. Therefore, running RVIC parameters command would throw this:

slim@devel2:~/Desktop/hydro_data$ rvic parameters sample_parameter_config.cfg
-->> Could not load xarray!! <<--
INFO:init_logger>> -------------------- INITIALIZED RVIC LOG ------------------
INFO:init_logger>> LOG LEVEL: DEBUG
INFO:init_logger>> Logging To Console: True
INFO:init_logger>> LOG FILE: ./routing/sample/logs/RVIC-20200714-171433.log
INFO:init_logger>> ----------------------------------------------------------

INFO:gen_uh_init>> plots directory is ./routing/sample/plots
INFO:gen_uh_init>> logs directory is ./routing/sample/logs
INFO:gen_uh_init>> params directory is ./routing/sample/params
INFO:gen_uh_init>> inputs directory is ./routing/sample/inputs
INFO:gen_uh_init>> aggregated directory is ./routing/sample/temp/aggregated
INFO:gen_uh_init>> remapped directory is ./routing/sample/temp/remapped
INFO:gen_uh_init>> Opened Pour Points File: ./routing/sample/inputs/sample_pour.txt
ERROR:gen_uh_init>> Error opening pour points file: ./routing/sample/inputs/sample_pour.txt
ERROR:gen_uh_init>> 'DataFrame' object has no attribute 'ix'
Traceback (most recent call last):
  File "/home/slim/.local/lib/python3.7/site-packages/rvic/parameters.py", line 188, in gen_uh_init
    pour_points.ix[i, 'names'] = strip_invalid_char(name)
  File "/home/slim/.local/lib/python3.7/site-packages/pandas/core/generic.py", line 5274, in __getattr__
    return object.__getattribute__(self, name)
AttributeError: 'DataFrame' object has no attribute 'ix'
ERROR:write>> Traceback (most recent call last):
ERROR:write>>   File "/home/slim/.local/bin/rvic", line 61, in <module>
ERROR:write>> main()
ERROR:write>>   File "/home/slim/.local/bin/rvic", line 43, in main
ERROR:write>> parameters(args.config_file, numofproc=args.numofproc)
ERROR:write>>   File "/home/slim/.local/lib/python3.7/site-packages/rvic/parameters.py", line 51, in parameters
ERROR:write>> outlets, config_dict, directories = gen_uh_init(config_file)
ERROR:write>>   File "/home/slim/.local/lib/python3.7/site-packages/rvic/parameters.py", line 188, in gen_uh_init
ERROR:write>> pour_points.ix[i, 'names'] = strip_invalid_char(name)
ERROR:write>>   File "/home/slim/.local/lib/python3.7/site-packages/pandas/core/generic.py", line 5274, in __getattr__
ERROR:write>> return object.__getattribute__(self, name)
ERROR:write>> AttributeError
ERROR:write>> :
ERROR:write>> 'DataFrame' object has no attribute 'ix'

I suggest replacing .ix to .loc indexer as the pandas doc recommends.

[sum1lim]

pacificclimate/osprey#5