Example 4: Create video
=======================

This example demonstrates how to import file and create video with GINCCO_lib
using :func:`GINCCO_lib.image_to_video.pngs_to_video`.


Code Example
------------

Now we will import the library and the grid

.. code-block:: python

    # =========================
    # IMPORTS
    # =========================
    import numpy as np
    import GINCCO_lib as gc
    from netCDF4 import Dataset
    from datetime import *

    # =========================
    # CONFIGURATION
    # =========================
    tstart = datetime(2010, 1, 1)
    tend   = datetime(2010, 1, 10)

    path = '/work/users/tungnd/GOT271/GOT_REF5/OFFLINE/'

    # =========================
    # LOAD GRID
    # =========================
    fgrid = Dataset(path + 'grid.nc', 'r')
    lat_t = fgrid.variables['latitude_t'][:]
    lon_t = fgrid.variables['longitude_t'][:]
    mask_t_var = fgrid.variables['mask_t']
    if mask_t_var.ndim == 3:
        mask_t = mask_t_var[0, :, :]
    elif mask_t_var.ndim == 2:
        mask_t = mask_t_var[:, :]
    dx_t  = fgrid.variables['dx_t'][:,:]
    dy_t  = fgrid.variables['dy_t'][:,:]
    sin_t  = fgrid.variables['gridrotsin_t'][:,:]
    cos_t  = fgrid.variables['gridrotcos_t'][:,:]


Now import data

.. code-block:: python


    # Step 1: Import data
    ssh = gc.import_3D(path, 'ssh_ib', tstart, tend, ignore_missing='False')


    data_draw = ssh[0]
    data_draw[mask_t==0] = np.nan


    gc.map_draw(
        lon_min=105, lon_max=111,
        lat_min=16.5, lat_max=22,
        title="ssh",
        lon_data=lon_t,
        lat_data=lat_t,
        data_draw=data_draw,
        path_save="/prod/projects/data/tungnd/figure/",
        name_save="ssh"
    )


Now choose a day and calculate

.. code-block:: python

    #Step 2: Choose a day and calculate
    U1, V1 = gc.geostrophic_current(data_draw, lat_t, dx_t, dy_t, sin_t, cos_t)

    for i in range(0,11):
        print (i*10,  np.nanpercentile(U1, i*10),np.nanpercentile(V1, i*10))


    #Step 4: Draw
    gc.map_draw_uv(
        lon_min=105, lon_max=111,
        lat_min=16.5, lat_max=22,
        title="Geotrophic current (example 7)",
        lon_data=lon_t,
        lat_data=lat_t,
        data_u= U1, data_v= V1,
        mask_ocean = mask_t,
        path_save="/prod/projects/data/tungnd/figure/",
        name_save="geotrophic_current_example7",
        quiver_max_n=20,   # ~max arrows per axis (auto step so arrows <= quiver_max_n x quiver_max_n)
        quiver_scale=6  # higher is shorter arrow. lower is longer arrow
    )