Hi Jim
So when you type:
ax.set_extent([-135, -60, 10, 65], crs=ccrs.Mercator())
You are telling cartopy "set the extents of the axes to a box with lower
left corner (-135, 10) and upper right corner (-60, 65); those points are
native coordinates in the Mercator() projection". You essentially specified
a 75m x 55m box. To plot with Mercator you want:
# Tell cartopy the axes we're plotting on should be in Mercator
ax = fig.add_subplot(1, 1, 1, projection=Mercator())
# Specify the extent as lat/lon
ax.set_extent([-135, -60, 10, 65], crs=ccrs.PlateCarree())
Hope this helps!
Ryan
On Thu, Nov 18, 2021 at 11:54 AM Weber, Jim <Jim.Weber@xxxxxxx> wrote:
> Below is a snippet of code from Brian Blaylock’s True Color Recipe. I am
> trying to instead display imagery in a Mercator projection. I thought I
> would do this with a line such as:
>
> mc=cartopy.ccrs.Mercator(*central_longitude=0.0*, *min_latitude=-80.0*,
> *max_latitude=84.0*, *globe=None*)
>
>
>
> and then have lines:
>
> ax = fig.add_subplot(1, 1, 1, projection=mc)
>
> ax.set_extent([-135, -60, 10, 65], crs=ccrs.Mercator())
>
>
>
> but this does not work. Can someone point out what I am doing wrong or
> point me to the correct resource so I might understand my problem better?
>
>
>
>
>
> Thanks, Jim
>
>
>
> ------ Code snippet ---------
>
>
>
>
>
> fig = plt.figure(figsize=(15, 12))
>
>
>
> # Generate an Cartopy projection
>
> lc = ccrs.LambertConformal(central_longitude=-97.5,
> standard_parallels=(38.5,
>
>
> 38.5))
>
>
>
> ax = fig.add_subplot(1, 1, 1, projection=lc)
>
> ax.set_extent([-135, -60, 10, 65], crs=ccrs.PlateCarree())
>
>
>
> ax.imshow(RGB, origin='upper',
>
> extent=(x.min(), x.max(), y.min(), y.max()),
>
> transform=geos,
>
> interpolation='none')
>
> ax.coastlines(resolution='50m', color='black', linewidth=0.5)
>
> ax.add_feature(ccrs.cartopy.feature.STATES, linewidth=0.5)
>
>
>
> plt.title('GOES-16 True Color', loc='left', fontweight='bold', fontsize=15)
>
> plt.title('{}'.format(scan_start.strftime('%d %B %Y %H:%M UTC ')),
> loc='right')
>
>
>
> plt.show()
>
>
>
>
>
>
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