spreadrose module

angle_from_2pts(p1, p2)

Calculate the clockwise angles between the fire vector and the North from start and end points of a vector.

Parameters:

Name	Type	Description	Default
p1	GeoDataFrame	starting point of a vector with geometry.	required
p2	GeoDataFrame	end point of a vector with geometry.	required

Returns:

Type	Description
degree	return angle value

Source code in postbp/spreadrose.py

def angle_from_2pts(p1, p2):
    """Calculate the clockwise angles between the fire vector and the North from start and end points of a vector.

    Args:
        p1 (GeoDataFrame): starting point of a vector with geometry.
        p2 (GeoDataFrame): end point of a vector with geometry.

    Returns:
        degree: return angle value
    """    
    x0, y0 = p1['geometry'].x,p1['geometry'].y
    x1, y1 = p2['geometry'].x, p2['geometry'].y
    dy = y0 - y1
    dx = x0 - x1
    theta = atan2(dx, dy)
    angle = degrees(theta)
    if angle < 0:
        angle = 360 + angle
    return angle

angle_from_pij(record)

Calculate the clockwise angles between the fire vector and the North from postbp function generate_daily_vectors.

Parameters:

Name	Type	Description	Default
record	DataFrame	a row of outputs from pij_from_vectors function	required

Returns:

Type	Description
degree	return angle value

Source code in postbp/spreadrose.py

def angle_from_pij(record):
    """Calculate the clockwise angles between the fire vector and the North from postbp function generate_daily_vectors.

    Args:
        record (DataFrame): a row of outputs from pij_from_vectors function

    Returns:
        degree: return angle value
    """    
    x0, y0 = record['geometry_x'].x, record['geometry_x'].y
    x1, y1 = record['geometry_y'].x, record['geometry_y'].y
    dy = y0 - y1
    dx = x0 - x1
    theta = atan2(dx, dy)
    angle = degrees(theta)
    if angle < 0:
        angle = 360 + angle
    return angle

generate_fire_rose(pijVectors, nodes, **kwargs)

Prepare data for plotting fire rose.

Parameters:

Name	Type	Description	Default
pijVectors	DataFrame	outputs from pij_from_vectors function	required
nodes	GeoDataFrame	centroid points of the hexagonal patch network	required

Returns:

Type	Description
DataFrame	return a dataframe containing angles, pij, and distance of spread.

Source code in postbp/spreadrose.py

def generate_fire_rose(pijVectors, nodes, **kwargs):
    """Prepare data for plotting fire rose.

    Args:
        pijVectors (DataFrame): outputs from pij_from_vectors function
        nodes (GeoDataFrame): centroid points of the hexagonal patch network

    Returns:
        DataFrame: return a dataframe containing angles, pij, and distance of spread. 
    """    
    node = nodes.copy()
    pij = pijVectors.copy() 
    if 'Node_ID' in kwargs:
        node = node.rename(columns={kwargs["Node_ID"]: 'Node_ID'})
    if 'column_i' in kwargs:
        pij.rename(columns={kwargs["column_i"]: 'column_i'}, inplace=True)    
    if 'column_j' in kwargs:
        pij.rename(columns={kwargs["column_j"]: 'column_j'}, inplace=True)     

    pij = node.merge(pij, left_on = 'Node_ID', right_on = 'column_i', how = 'right')
    pij = pij.merge(node, left_on = 'column_j', right_on = 'Node_ID', how = 'left')    
    pij.drop(labels = ['Node_ID_x', 'Node_ID_y'], axis = 1, inplace = True)
    for index, row in tqdm(pij.iterrows()):
        pij.at[index, 'angle'] = angle_from_pij(row)
    dffLine = [LineString(xy) for xy in zip(pij['geometry_x'], pij['geometry_y'])]
    pij = gpd.GeoDataFrame(pij, crs = node.crs, geometry = dffLine )
    pij.drop(labels = ['geometry_x', 'geometry_y'], axis = 1, inplace = True)
    pij['len'] = pij.geometry.length
    pij['pij'] = pij['pij'].astype(float)
    return pij

plot_rose(pijRose, column='pij', save=False)

Plot fire rose.

Parameters:

Name	Type	Description	Default
pijRose	DataFrame	a dataframe containing angles, pij, and distance of spread.	required
column	str	value can be 'pij' or 'len'. Defaults to 'pij'.	'pij'
save	bool	whether save the plot to current repository or plot on screen. Defaults to False.	False

Source code in postbp/spreadrose.py

def plot_rose(pijRose, column='pij', save = False):
    """Plot fire rose.

    Args:
        pijRose (DataFrame): a dataframe containing angles, pij, and distance of spread. 
        column (str, optional): value can be 'pij' or 'len'. Defaults to 'pij'.
        save (bool, optional): whether save the plot to current repository or plot on screen. Defaults to False.
    """    

    plt.rcParams.update({'font.size': 20,"legend.frameon":False})
    ax = WindroseAxes.from_ax()
    ax.bar(pijRose['angle'], pijRose[column], normed=True, blowto=False, cmap=cm.Set2, opening=0.8, edgecolor='white')
    ax.set_legend(fontsize="20",loc=(1.1, 0.01))
    if save:
        plt.savefig(column + 'Rose.png', bbox_inches='tight', pad_inches=.1, transparent=False)
        plt.close()
    else:
        plt.show()

    plt.rcParams.update(plt.rcParamsDefault)