Fix/structure final-draft edits

[Hamish Steptoe (hsteptoe)]

Following Rosanna (@rosannaamato) review of draft worksheets, this pull request contains all the commits relating to those changes. Full review and summaries of changes made following Rosanna (@rosannaamato) review can be seen in #21

This final draft to be reviewed and tested by Cathryn Fox (@cathrynjfox)

[Cathryn Fox (cathrynjfox)]

Review and run-through of worksheets:

Worksheet 1
f) suggest adding short explanation of why 'pmi2' means 1982
h) it's a bit confusing that the pictured example is for air temperature but the loaded cube is for precipitation
j) this code block takes longer to run than the previous ones. Suggest saying that this will happen so that users don't think it isn't working (as I did).

Worksheet 2
2.1 - there is a good explanation of a cube here, but we have already met cubes in worksheet 1. Maybe this could be moved to worksheet 1?
e) The input and output file names are already specified in the code block, presumably so that later code loads them easily. Worth stating this in the instructions

Worksheet 3
a) The activity is to sort the lat and lons, but then they are already entered into the code box
c) There's a lot of unexplained functions in this code block i.e. weightings. Is this explained in the presentations? If not can a line be inserted to give a brief explanation. EDIT - this line exists in a note below the code block. Can it be moved to above?
e) I got a warning "Using DEFAULT_SPHERICAL_EARTH_RADIUS." - should this concern me?
Code block with line "aphro_monthly_mean.coord_system()" - why is this here?
Question about plotting aphro data - there isn't a block to put the code in, or any guidance on how to do this
f) Suggest a blue note box explaining what masking is
Code block containing the masking, I got a FutureWarning:

/opt/scitools/environments/experimental/2018_10_16-1/lib/python3.6/site-packages/numpy/ma/core.py:3169: FutureWarning: Using a non-tuple sequence for multidimensional indexing is deprecated; use arr[tuple(seq)] instead of arr[seq]. In the future this will be interpreted as an array index, arr[np.array(seq)], which will result either in an error or a different result.
dout = self.data[indx]
/opt/scitools/environments/experimental/2018_10_16-1/lib/python3.6/site-packages/iris/analysis/_scipy_interpolate.py:290: FutureWarning: Using a non-tuple sequence for multidimensional indexing is deprecated; use arr[tuple(seq)] instead of arr[seq]. In the future this will be interpreted as an array index, arr[np.array(seq)], which will result either in an error or a different result.
return self.values[idx_res]

Still f) We fixed the bit where it was trying to plot cahpa_cube instead of cahpa_regrid

Worksheet 4
a) I got an error:

/opt/scitools/environments/experimental/2018_10_16-1/lib/python3.6/site-packages/iris/fileformats/_pyke_rules/compiled_krb/fc_rules_cf_fc.py:2076: UserWarning: Failed to create 'grid_longitude' dimension coordinate: The points array must be strictly monotonic.
Gracefully creating 'grid_longitude' auxiliary coordinate instead.
error=e_msg))

But it still worked.
EDIT - Hamish fixed something and I no longer get this error

I added in the names of the two cubes to the green question box so that it was clearer.

b) I got a ValueError, Hamish fixed something and I no longer get an error.
c) We fixed this. Problems were
1) it was calling the time_periods key instead of the period
2) Hamish has already changed the units to C, so no longer need to do this

e) I got a UserWarning error about non-bounded coordinates, but it still worked.

h) You have to scroll a long way to remember what the original temp data files are called, suggest giving them in this code box

Worksheet 5
b) This was quite hard BUT I DID MANAGE IT HAMISH.
Had to scroll down to see what the filenames should be when plotting later, suggest providing the infile and outfile names as has happened in all previous examples. Also - that "number_aphro_days" should be called "number_aphro_days".

Worksheet 6
I have read through this for spellings, but not actually done the activity.

[Cathryn Fox (cathrynjfox)]

f07d4a9 pushed changes to worksheets following the review