xoa.sigma.get_cs

xoa.sigma.get_cs(sig, thetas, thetab, cs_type=None)

Get a s-coordinate stretching curve

Parameters

• sig (xarray.DataArray) – Sigma coordinates range from 0 to 1 (\(s\) | s)

• thetas (xarray.DataArray) – Surface control parameter (\(a\) | a)

• thetab (xarray.DataArray) – Bottom control parameter (\(b\) | b)

• cs_type (str, None) –

  Stretching type:

  None (default):

  \[C & = (1-b)*\frac{\sinh(a*s)}{\sinh(a)} + b*\left[\frac{\tanh(a*(s+0.5))}{2*\tanh(0.5*a)} - 0.5\right]\]

Returns

xarray.DataArray – Stretching curve (\(C\) | C)