[python #OAQ-273853]: Q-vector divergence, and "too many positional arguments"

Hello, and thanks for reaching out!

The Q-vector example on the python-training website is currently out-of-date 
and will be updated for MetPy 1.1 soon. Your code adaptation for MetPy>=1.0 is 
close! For this to work:

1.) `dx` and `dy` are now "keyword-only" arguments, not "positional" arguments. 
This means you need to specify the name of the keyword. For example,

    q_div = mpcalc.divergence(uqvect, vqvect, dx=dx, dy=dy, ...)

2.) `x_dim` and `y_dim` are to specify the positional number of the axis for 
each, NOT the total length of those. For example,

    q_div = mpcalc.divergence(uqvect, vqvect, dx=dx, dy=dy, x_dim=1, y_dim=0)

where I'm telling the function that my x-dimension is the SECOND of my 
dimensions of the array (note Python 0-indexing rules), and my y-dimension is 
the first dimension of the array.

Some notes: If you work with parsed Xarray data [1] in these calculations, you 
can get by without specifying any of these at all! Also, MetPy's default 
`x_dim` and `y_dim` ordering will end up working for many datasets, especially 
in our examples. You may not have to set these at all, depending on the data 
you're working with. I hope this helps, and don't hesitate to follow up if I 
can offer any more clarification. Thanks!


[1]: https://unidata.github.io/MetPy/latest/tutorials/xarray_tutorial.html


All the best,

Drew


> Last fall, I used the wonderful Q-vector example from the MetPy webpage,
> modified to plot user-specified current data.  My students and I found it
> very useful.
> 
> This fall, the same code fails at the point where it goes to compute the
> Q-vector divergence.  I've tried to modify the code to be consistent with
> MetPy1.0, but when I run that line, even when configured exactly as in the
> docs, I get the error "TypeError: too many positional arguments".
> 
> The code I am using (one of many attempted variations) is here:
> q_div = mpcalc.divergence(uqvect, vqvect, dx, dy, x_dim=260, y_dim=87)
> 


Ticket Details
===================
Ticket ID: OAQ-273853
Department: Support Python
Priority: Low
Status: Closed
===================
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