Change longitude from -180 to 180 to 0 to 360

Question

I want to change my longitude from -180 degrees to 180 deg format to 0-360 for an array. Is there a way to do this with out using loops or if statements?

lon_04_window = [ 1.39698386e-09   6.53551058e-02   1.30710210e-01   1.96065315e-01 2.61420419e-01   3.26775523e-01   3.92130628e-01   4.57485732e-01 5.22840836e-01   5.88195941e-01   6.53551045e-01   7.18906150e-01 7.84261254e-01   8.49616358e-01   9.14971463e-01   9.80326567e-01 1.04568167e+00   1.11103678e+00   1.17639188e+00   1.24174698e+00 1.30710209e+00   1.37245719e+00   1.43781230e+00   1.50316740e+00 1.56852251e+00   1.63387761e+00   1.69923272e+00   1.76458782e+00 1.82994292e+00   1.89529803e+00   1.96065313e+00   2.02600824e+00 2.09136334e+00   2.15671845e+00   2.22207355e+00   2.28742865e+00 2.35278376e+00   2.41813886e+00   2.48349397e+00   2.54884907e+00 2.61420418e+00   2.67955928e+00   2.74491439e+00   2.81026949e+00]

Loop Code:

for i in range(len(lon)):
    if lon[i] < 0:
        lon[i] = lon[i]+360

Answer 1

Assuming lon_04_window is a numpy array AND that you want to go from [0,360] to [-180,180]:

((lon_04_window - 180) % 360) - 180

or

np.mod(lon_04_window - 180.0, 360.0) - 180.0

If you actually want to go from [-180,180] range to [0, 360] as stated in the OP:

lon_04_window % 360

If lon_04_window is not a numpy array, make it:

import numpy as np
lon_04_window = np.asarray(lon_04_window)

Answer 2

def rewrap(x):
    return (x + 180) % 360 - 180

This can also be applied directly to NumPy arrays, not just scalars.

Answer 3

np.mod(lon_04_window, 360)正常工作。

Answer 4

In PostgresSQL:

UPDATE table SET lon = lon -360 WHERE lon > 180 ;  

If the 0 begins in Greenwich.