Test Interpolators

Brendan Smithyman | March, 2016



In [1]:

    
import sys
import warnings
sys.path.append('../..')



In [2]:

    
from zephyr.backend import SplineGridInterpolator
from zephyr.middleware import FullwvDatastore

Setup

Read a configuration from xhlayr.ini and xhlayr.vp, and set up a scale factor of 1.5; i.e., $sdx = 1.5\times dx$.



In [3]:

    
fds = FullwvDatastore('xhlayr')
systemConfig = fds.systemConfig
scu = {
    'scale': 1.5,
}
systemConfig.update(scu)

Create a SplineGridInterpolator, which behaves like an $8911\times 20000$ matrix.



In [4]:

    
sgi = SplineGridInterpolator(systemConfig)
print(sgi.shape)









    



(8911.0, 20000)

Get the velocity c from the systemConfig, downsample it to create cn, and then apply the transpose of the operation to get cr.



In [5]:

    
with warnings.catch_warnings():
    warnings.simplefilter('ignore')
    
    c = systemConfig['c']
    cn = (sgi * c).reshape((sgi.snz, sgi.snx))
    cr = (sgi.T * cn).reshape((sgi.nz, sgi.nx))

Results



In [6]:

    
%pylab inline









    



Populating the interactive namespace from numpy and matplotlib



In [7]:

    
with warnings.catch_warnings():
    warnings.simplefilter('ignore')
    

    plotOpts = {
        'vmin': c.min(),
        'vmax': c.max(),
    }

    subplot(1,3,1)
    imshow(c, **plotOpts)
    colorbar(shrink=0.5)
    title('Original')

    subplot(1,3,2)
    imshow(cn, **plotOpts)
    colorbar(shrink=0.5)
    title('Rescaled')

    subplot(1,3,3)
    imshow(cr, **plotOpts)
    colorbar(shrink=0.5)
    title('After adjoint')

    tight_layout()









    



/Users/brendan/anaconda/lib/python2.7/site-packages/matplotlib/collections.py:590: FutureWarning: elementwise comparison failed; returning scalar instead, but in the future will perform elementwise comparison
  if self._edgecolors == str('face'):



In [8]:

    
nLoops = 100

ca = c
sgiT = sgi.T
for i in xrange(nLoops):
    cb = sgi*ca
    ca = sgiT*cb
ca.shape = (sgi.nz,sgi.nx)

plotOpts = {
    'vmin': c.min(),
    'vmax': c.max(),
}

subplot(1,2,1)
imshow(c, **plotOpts)
colorbar(shrink=0.5)
title('Original')

subplot(1,2,2)
imshow(ca, **plotOpts)
colorbar(shrink=0.5)
title('After %d loops'%nLoops)









    Out[8]:





<matplotlib.text.Text at 0x10a974950>



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