2017-08-04 127 views
0

正如標題所暗示的,我試圖編寫一個函數來計算任何輸入節點所屬的週期數。我發現了一個有用的video,它解釋了查找循環的算法背後的理論,但我無法理解如何使用networkX而不是網站使用的數據結構來實現它。我無法理解白色/灰色/等等設置概念以及遍歷網絡並查找循環。python:檢測網絡中的一個循環X

我的函數參數/結構:

def feedback_loop_counter(G, node): 
    c = 0 
    calculate all cycles in the network 
    for every cycle node is in, increment c by 1 
    return c 

該網絡具有輸入和輸出節點過,我不清楚有那些玩成計算週期

這是我輸入網絡:

import networkx as nx 
import matplotlib.pyplot as plt 
G=nx.DiGraph() 
molecules = ["CD40L", "CD40", "NF-kB", "XBP1", "Pax5", "Bach2", "Irf4", "IL-4", "IL-4R", "STAT6", "AID", "Blimp1", "Bcl6", "ERK", "BCR", "STAT3", "Ag", "STAT5", "IL-21R", "IL-21", "IL-2", "IL-2R"] 
Bcl6 = [("Bcl6", "Bcl6"), ("Bcl6", "Blimp1"), ("Bcl6", "Irf4")] 
STAT5 = [("STAT5", "Bcl6")] 
IL_2R = [("IL-2R", "STAT5")] 
IL_2 = [("IL-22", "IL-2R")] 
BCR = [("BCR", "ERK")] 
Ag = [("Ag", "BCR")] 
CD40L = [("CD40L", "CD40")] 
CD40 = [("CD40", "NF-B")] 
NF_B = [("NF-B", "Irf4"), ("NF-B", "AID")] 
Irf4 = [("Irf4", "Bcl6"), ("Irf4", "Pax5"), ("Irf4", "Irf4"), ("Irf4", "Blimp1")] 
ERK = [("ERK", "Bcl6"), ("ERK", "Blimp1"), ("ERK", "Pax5")] 
STAT3 = [("STAT3", "Blimp1")] 
IL_21 = [("IL-21", "IL-21R")] 
IL_21R = [("IL-21R", "STAT3")] 
IL_4R = [("IL-4R", "STAT6")] 
STAT6 = [("STAT6", "AID"), ("STAT6", "Bcl6")] 
Bach2 = [("Bach2", "Blimp1")] 
IL_4 = [("IL-4", "IL-4R")] 
Blimp1 = [("Blimp1", "Bcl6"), ("Blimp1", "Bach2"), ("Blimp1", "Pax5"), ("Blimp1", "AID"), ("Blimp1", "Irf4")] 
Pax5 = [("Pax5", "Pax5"), ("Pax5", "AID"), ("Pax5", "Bcl6"), ("Pax5", "Bach2"), ("Pax5", "XBP1"), ("Pax5", "ERK"), ("Pax5", "Blimp1")] 
edges = Bcl6 + STAT5 + IL_2R + IL_2 + BCR + Ag + CD40L + CD40 + NF_B + Irf4 + 
ERK + STAT3 + IL_21 + IL_21R + IL_4R + STAT6 + Bach2 + IL_4 + Blimp1 + Pax5 
G.add_nodes_from(molecules) 
G.add_edges_from(edges) 
sources = ["Ag", "CD40L", "IL-2", "IL-21", "IL-4"] 
targets = ["XBP1", "AID"] 

回答

1

我會寫你感興趣的是「簡單的循環」的假設下,我的答案代碼,也就是,只有重複節點是第一個/最後一個節點的週期。

把那些有邊緣的節點加入節點u(「輸入節點」)。然後使用networkx命令all_simple_paths查找從u到每個輸入節點的所有簡單路徑。這些都是一個簡單的循環。

+0

是否這樣做,似乎它給我很好的輸出後,我也手動檢查網絡。謝謝你的幫助。 – witcheR

1

尋找週期的想法是做一個Depth-first search,當你這樣做時,記住你已經看到了哪些節點以及它們的路徑。如果碰巧訪問了您已經看到的節點,那麼就有一個循環,您可以通過連接路徑來找到它。

試着寫一些代碼來做到這一點,並打開一個新的問題與如果您遇到