gnome.utilities.transforms

Functions

r_theta_to_uv_current(r_theta)	Converts array of current values given with magnitude, direction into
uv_to_r_theta_current(uv)	Converts array of current values given with (u,v) current values to
r_theta_to_uv_wind(r_theta)	Converts array of wind values given with magnitude, direction into(u,v)
uv_to_r_theta_wind(uv)	Converts array of wind values given with (u,v) wind values to magnitude,

Module Contents

gnome.utilities.transforms.r_theta_to_uv_current(r_theta)

Converts array of current values given with magnitude, direction into (u,v) wind values. Current from 0 deg is (u,v) = (0,1), from 45 deg (u,v) = (1,1) i.e. rotate clockwise from North. In addition, (u,v) represents the direction the current moves towards.

Parameters:

r_theta – NX2 numpy array containing r = r_theta[:,0], theta = r_theta[:,1]. Theta is in degrees between 0 and 360.

Returns:

NX2 numpy array containing the corresponding uv Cartesian velocity vector

gnome.utilities.transforms.uv_to_r_theta_current(uv)

Converts array of current values given with (u,v) current values to magnitude, direction. Current from 0 deg is (u,v) = (0,1), from 45 deg (u,v) = (1,1) i.e. rotate clockwise from North. In addition, (u,v) represents the direction the current blows towards

Parameters:

uv – NX2 numpy array, where each row corresponds with a velocity vector

Returns:

NX2 numpy array containing polar coordinates r_theta

gnome.utilities.transforms.r_theta_to_uv_wind(r_theta)

Converts array of wind values given with magnitude, direction into(u,v) wind values. Wind from 0 deg is (u,v) = (0,-1), from 45 deg (u,v) = (-1,-1) i.e. rotate clockwise from North. In addition, (u,v) represents the direction the wind blows towards

Parameters:

r_theta – NX2 numpy array containing r = r_theta[:,0], theta = r_theta[:,1]. Theta is in degrees between 0 and 360.

Returns:

NX2 numpy array containing the corresponding uv Cartesian velocity vector

gnome.utilities.transforms.uv_to_r_theta_wind(uv)

Converts array of wind values given with (u,v) wind values to magnitude, direction. Wind from 0 deg is (u,v) = (0,-1), from 45 deg (u,v) = (-1,-1) i.e. rotate clockwise from North. In addition, (u,v) represents the direction the wind blows towards

Parameters:

uv – NX2 numpy array, where each row corresponds with a velocity vector

Returns:

NX2 numpy array containing polar coordinates r_theta