Exemplo n.º 1
0
def algorithm1(train1, train2):
    """
    - Performs algorithm 1 described in 'Mining Railway Delay Dependenies in
    Large-Scale Real-World Delay Data' (Flier, Gelashvili, Graffagnino,
    Nunkesser).
    - train1 and train2 must be numpy arrays containing delay times of the trains
    there can be no missing values, and train1[d], train2[d] must be delay data
    from the same day d. Implicitly train1 and train2 must be of equal length.
    """

    train1, train2 = trainsorting.sort_two_non_decreasing(train1, train2)
    train1 = trainsorting.append(train1, float('inf'))
    train2 = trainsorting.append(train2, float(0))

    #Locals
    diff = trainsorting.difference(train1, train2)
    points = 0
    points_star = 0
    bft = diff[0] #buffertime
    bft_star = 0
    lpi = 0 #last point index
    md_star = 0 # maximal delay

    #The algorithm:
    for i in range(len(train1)):
        if diff[i] > bft:
            if points > points_star:
                #update best solution
                points_star = points
                bft_star = bft
                md_star = train1[i-1]

            bft = diff[i]
            notdone = True
            while notdone:
                if (train1[lpi] < bft and
                    lpi < len(train1)):
                    lpi += 1
                else:
                    notdone = False
            points = i - lpi + 1
        else:
            points += 1

    return (points_star, bft_star, md_star)
Exemplo n.º 2
0
def algorithm2(train1, train2, minwidth=1):
    """
    - Performs algorithm 2 described in 'Mining Railway Delay Dependenies in
    Large-Scale Real-World Delay Data' (Flier, Gelashvili, Graffagnino,
    Nunkesser).
    - Optional parameter minwidth describes the minimum requiered headway
    between trains using the same infrastructure, varies from station to
    station.
    - train1 and train2 must be numpy arrays containing delay times of the trains
    there can be no missing values, and train1[d], train2[d] must be delay data
    from the same day d. Implicitly train1 and train2 must be of equal length.
    """
    train1 = trainsorting.append(train1, float('inf'))
    train2 = trainsorting.append(train2, 0)

    #Locals
    intercepts = sorted(trainsorting.difference(train1, train2))
    points = 0
    points_star = 0
    left = 0
    leftstar = 0
    right = 0
    rightstar = 0
    fai = 0 #index of first point above stripe

    #The algorithm
    for j in range(1, len(intercepts)):
        left = intercepts[j-1]
        right = intercepts[j]
        if right - left >= minwidth:

            while train1[fai] < left:
                fai += 1

            points = j - fai
            if points > points_star:
                #update best solution
                points_star = points
                leftstar = left
                rightstar = right

    return (points_star, leftstar, rightstar)