:orphan:

.. _projections:

Projections in cf-plot
**********************

The cylindrical and polar stereographic projections are detailed separately in `cylindrical plots <cylindrical>` and `polar plots <polar>`.



Example 31 - UKCP projection
----------------------------

.. image::  images/fig31.png
   :scale: 52%

::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/ukcp_rcm_test.nc')[0]
   cfp.mapset(proj='UKCP', resolution='50m')
   cfp.levs(-3, 7, 0.5)
   cfp.setvars(grid_x_spacing=1, grid_y_spacing=1)
   cfp.con(f, lines=False)

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cf-plot looks for auxiliary coordinates of longitude and latitude and uses them if found.  If they aren't present then cf-plot will generate the grid required using the projection_x_coordinate and projection_y_coordinate variables.  For a blockfill plot as below it uses the latter method and the supplied bounds.

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Example 32 - UKCP projection with blockfill
-------------------------------------------

New cfp.setvars options affecting the grid plotting for the UKCP grid are:

| grid=True - draw grid
| grid_spacing=1 - grid spacing in degrees
| grid_colour='black' - grid colour
| grid_linestyle='--' - grid line style
| grid_thickness=1.0 - grid thickness


Here we change the plotted grid with the grid_colour option to cfp.setvars, xticks and yticks options to cfp.con  and make a blockfill plot.

.. image::  images/fig32.png
   :scale: 52%

::

   import cf
   import cfplot as cfp
   import numpy as np
   f=cf.read('cfplot_data/ukcp_rcm_test.nc')[0]
   cfp.mapset(proj='UKCP', resolution='50m')
   cfp.levs(-3, 7, 0.5)
   cfp.setvars(grid_colour='grey')
   cfp.con(f, lines=False, blockfill=True, xticks=np.arange(14)-11, yticks=np.arange(13)+49)

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Example 33 - OSGB and EuroPP projections
----------------------------------------

.. image::  images/fig33.png
   :scale: 52%

::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/ukcp_rcm_test.nc')[0]
   cfp.levs(-3, 7, 0.5)
   cfp.gopen(columns=2)
   cfp.mapset(proj='OSGB', resolution='50m')
   cfp.con(f, lines=False, colorbar_label_skip=2)
   cfp.gpos(2)
   cfp.mapset(proj='EuroPP', resolution='50m')
   cfp.con(f, lines=False, colorbar_label_skip=2)
   cfp.gclose()

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Example 34 - Cropped Lambert conformal projection
-------------------------------------------------

.. image::  images/fig34.png
   :scale: 52%


Lambert conformal projections can now be cropped as in the following code:

::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/tas_A1.nc')[0]
   cfp.mapset(proj='lcc', lonmin=-50, lonmax=50, latmin=20, latmax=85)
   cfp.con(f.subspace(time=15))



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Example 35 - Mollweide projection
---------------------------------

.. image::  images/fig35.png
   :scale: 52%


::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/tas_A1.nc')[0]
   cfp.mapset(proj='moll')
   cfp.con(f.subspace(time=15))



Example 36 - Mercator projection
--------------------------------

.. image::  images/fig36.png
   :scale: 52%


::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/tas_A1.nc')[0]
   cfp.mapset(proj='merc')
   cfp.con(f.subspace(time=15))

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Example 37 - Orthographic projection
------------------------------------

.. image::  images/fig37.png
   :scale: 52%


::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/tas_A1.nc')[0]
   cfp.mapset(proj='ortho')
   cfp.con(f.subspace(time=15))



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Example 38 - Robinson projection
--------------------------------

.. image::  images/fig38.png
   :scale: 52%


::

   import cf
   import cfplot as cfp
   f=cf.read('cfplot_data/tas_A1.nc')[0]
   cfp.mapset(proj='robin')
   cfp.con(f.subspace(time=15))



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