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[python #XNB-470459]: A question about wind barbs in the dateline of the Pacific (180 degrees) using Cartopy?

Greetings!

> First, I keep missing your python classes, our you have any online classes 
> soon?

We haven't offered an online one in a bit, we've been working behind the scenes 
on reworking how we offer that training. I'll keep a note of your interest as 
we look towards our next workshop schedule.

> Second, I would like to show 100mb winds across the Pacific (see attachment). 
> I can do this with contouring packages using the following code segments:

I was able to make a quiver work with some synthetic data as:

    import cartopy.crs as ccrs
    import cartopy.feature as cfeature
    import matplotlib.pyplot as plt
    import numpy as np
    
    center_lon = 180
    
    fig = plt.figure(figsize=[9, 9], facecolor='lightgrey')
    ax = fig.add_subplot(1, 1, 1, 
projection=ccrs.PlateCarree(central_longitude=center_lon))
    
    ax.set_extent([100, 265, -25, 50], crs=ccrs.PlateCarree())
    
    ax.add_feature(cfeature.STATES, edgecolor='white', linewidth=1.5)
    ax.add_feature(cfeature.COASTLINE, edgecolor='white', linewidth=2.0)
    ax.add_feature(cfeature.LAND)
    
    lon = np.linspace(-120, 120, 10)
    lat = np.linspace(-10, 40, 5)
    lon2D_sub, lat2D_sub = np.meshgrid(lon, lat)
    u_sub = np.full_like(lon2D_sub, 5)
    v_sub = np.full_like(lon2D_sub, 5)
    
    Q = plt.quiver(lon2D_sub, lat2D_sub, u_sub, v_sub, angles="xy", 
color='black',
        units='width',transform=ccrs.PlateCarree(central_longitude=center_lon))

This worked fine for me here with Cartopy 0.21.1.

I suspect that this is heavily dependent on:

1. Having the data in the right "kind" of longitude; I used the -180 -> 180 
system
2. Having the data for the eastern hemisphere before the data for the western

Maybe the synthetic data I created above can shed some light on where yours 
differs?

Hope this helps,

Ryan

Ticket Details
===================
Ticket ID: XNB-470459
Department: Support Python
Priority: Low
Status: Closed
===================
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