reinstate fit_extent_to_regis under a different name

[OnnoEbbens]

The fit_extent_to_regis function resized a random extent in such a way that there will be an integer number of columns and cells given a certain cellsize. This is useful in case you want to quickly create a grid from a random extent.

I would propose to reinstate the function under the name snap_extent in de grid module.

The original fit_extent_to_regis is:

def fit_extent_to_regis(extent, delr, delc, cs_regis=100.,
                        verbose=False):
    """
    redifine extent and calculate the number of rows and columns.

    The extent will be redefined so that the borders os the grid (xmin, xmax, 
    ymin, ymax) correspond with the borders of the regis grid.

    Parameters
    ----------
    extent : list, tuple or np.array
        original extent (xmin, xmax, ymin, ymax)
    delr : int or float,
        cell size along rows, equal to dx
    delc : int or float,
        cell size along columns, equal to dy
    cs_regis : int or float, optional
        cell size of regis grid. The default is 100..

    Returns
    -------
    extent : list, tuple or np.array
        adjusted extent
    nrow : int
        number of rows.
    ncol : int
        number of columns.

    """
    extent = extent.copy()
    
    if verbose:
        print(f'redefining current extent: {extent}, fit to regis raster')

    for d in [delr, delc]:
        if float(d) not in [10., 20., 25., 50., 100., 200., 400., 500., 800.]:
            print(f'you probably cannot run the model with this '
                  f'cellsize -> {delc, delr}')

    # if extents ends with 50 do nothing, otherwise rescale extent to fit regis
    if extent[0] % cs_regis == 0 or not extent[0] % (0.5 * cs_regis) == 0:
        extent[0] -= extent[0] % 100
        extent[0] = extent[0] - 0.5 * cs_regis
    # get number of columns
    ncol = int(np.ceil((extent[1] - extent[0]) / delr))
    extent[1] = extent[0] + (ncol * delr)  # round x1 up to close grid

    # round y0 down to next 50 necessary for regis
    if extent[2] % cs_regis == 0 or not extent[2] % (0.5 * cs_regis) == 0:
        extent[2] -= extent[2] % 100
        extent[2] = extent[2] - 0.5 * cs_regis
    nrow = int(np.ceil((extent[3] - extent[2]) / delc))  # get number of rows
    extent[3] = extent[2] + (nrow * delc)  # round y1 up to close grid

    if verbose:
        print(
            f'new extent is {extent} model has {nrow} rows and {ncol} columns')

    return extent, nrow, ncol

[rubencalje]

I think snap_extent would be a good name, and maybe return only the extent, and not nrow and ncol anymore.

[rubencalje]

Fixed by @OnnoEbbens