Python 熊猫按范围合并间隔
我有一个熊猫数据框,看起来如下所示:Python 熊猫按范围合并间隔,python,pandas,bioinformatics,Python,Pandas,Bioinformatics,我有一个熊猫数据框,看起来如下所示: chrom start end probability read 0 chr1 1 10 0.99 read1 1 chr1 5 25 0.99 read2 2 chr1 15 25 0.99 read2 3 chr1 30 40 0.75 read4 我想做的是合并具有相同染色体(色度列)且其坐标(开始、结束)
chrom start end probability read
0 chr1 1 10 0.99 read1
1 chr1 5 25 0.99 read2
2 chr1 15 25 0.99 read2
3 chr1 30 40 0.75 read4
我想做的是合并具有相同染色体(色度列)且其坐标(开始、结束)重叠的区间。在某些情况下,如果多个间隔相互重叠,则会有一些间隔应该合并,即使它们不重叠。请参见上述示例中的第0行和第2行以及下面合并的输出
对于那些被合并的元素,我想对它们的概率(概率列)求和,并计算“read”列中的唯一元素
使用上面的示例将产生以下输出,请注意,行0、1和2已合并:
chrom start end probability read
0 chr1 1 20 2.97 2
1 chr1 30 40 0.75 1
到目前为止,我一直在使用pybedtools merge进行这项工作,但事实证明,它执行数百万次的速度很慢(我的案例)。因此,我正在寻找其他选择,熊猫是显而易见的选择。我知道,使用pandasgroupby可以对要合并的列应用不同的操作,如nunique和sum,这是我需要应用的操作。尽管如此,pandas groupby仅将数据与精确的“色度”、“开始”和“结束”坐标合并
我的问题是,我不知道如何使用pandas根据坐标(色度、开始、结束)合并行,然后应用求和和努尼克操作
有没有快速的方法
谢谢
PS:正如我在我的问题上所说的,我已经做了数百万次了,所以速度是个大问题。因此,我不能使用pybedtools或纯python,这对我的目标来说太慢了
谢谢 IIUC
df.groupby((df.end.shift()-df.start).lt(0).cumsum()).agg({'chrom':'first','start':'first','end':'last','probability':'sum','read':'nunique'})
Out[417]:
chrom start end probability read
0 chr1 1 20 2.97 2
1 chr1 30 40 0.75 1
更多信息创建组密钥
(df.end.shift()-df.start).lt(0).cumsum()
Out[418]:
0 0
1 0
2 0
3 1
dtype: int32
正如@root所建议的,公认的答案无法推广到类似的情况。e、 g.如果我们在问题示例中添加范围为2-3的额外行:
df = pd.DataFrame({'chrom': ['chr1','chr1','chr1','chr1','chr1'],
'start': [1, 2, 5, 15, 30],
'end': [10, 3, 20, 25, 40],
'probability': [0.99, 0.99, 0.99, 0.99, 0.75],
'read': ['read1','read2','read2','read2','read4']})
…建议的聚合函数输出以下数据帧。请注意,4在1-10范围内,但它不再被捕获。范围1-10、2-3、5-20和15-25都重叠,因此应分组在一起
一种解决方案是以下方法(使用@W-B建议的聚合函数和组合区间的方法)
…它输出以下数据帧。第一行的总概率是3.96,因为我们组合了四行而不是三行
虽然这种方法应该更具普遍性,但它不一定很快!希望其他人能提出更快的替代方案。以下是使用和熊猫的答案。它的改进之处在于,它的合并速度非常快,易于并行化,即使在单核模式下也能快速实现超级复制
设置:
import pandas as pd
import pyranges as pr
import numpy as np
rows = int(1e7)
gr = pr.random(rows)
gr.probability = np.random.rand(rows)
gr.read = np.arange(rows)
print(gr)
# +--------------+-----------+-----------+--------------+----------------------+-----------+
# | Chromosome | Start | End | Strand | probability | read |
# | (category) | (int32) | (int32) | (category) | (float64) | (int64) |
# |--------------+-----------+-----------+--------------+----------------------+-----------|
# | chr1 | 149953099 | 149953199 | + | 0.7536048547309669 | 0 |
# | chr1 | 184344435 | 184344535 | + | 0.9358130407479777 | 1 |
# | chr1 | 238639916 | 238640016 | + | 0.024212603310159064 | 2 |
# | chr1 | 95180042 | 95180142 | + | 0.027139751993808026 | 3 |
# | ... | ... | ... | ... | ... | ... |
# | chrY | 34355323 | 34355423 | - | 0.8843190383030953 | 999996 |
# | chrY | 1818049 | 1818149 | - | 0.23138017743097572 | 999997 |
# | chrY | 10101456 | 10101556 | - | 0.3007915302642412 | 999998 |
# | chrY | 355910 | 356010 | - | 0.03694752911338561 | 999999 |
# +--------------+-----------+-----------+--------------+----------------------+-----------+
# Stranded PyRanges object has 1,000,000 rows and 6 columns from 25 chromosomes.
# For printing, the PyRanges was sorted on Chromosome and Strand.
执行:
def praderas(df):
grpby = df.groupby("Cluster")
prob = grpby.probability.sum()
prob.name = "ProbSum"
n = grpby.read.count()
n.name = "Count"
return df.merge(prob, on="Cluster").merge(n, on="Cluster")
%time result = gr.cluster().apply(praderas)
# 11.4s !
result[result.Count > 2]
# +--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------+
# | Chromosome | Start | End | Strand | probability | read | Cluster | ProbSum | Count |
# | (category) | (int32) | (int32) | (category) | (float64) | (int64) | (int32) | (float64) | (int64) |
# |--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------|
# | chr1 | 52952 | 53052 | + | 0.7411051557901921 | 59695 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 52959 | 53059 | + | 0.9979036360671423 | 356518 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 53029 | 53129 | + | 0.47409221639405397 | 104776 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 64657 | 64757 | + | 0.32465233067499366 | 386140 | 88 | 1.3880589602361695 | 3 |
# | ... | ... | ... | ... | ... | ... | ... | ... | ... |
# | chrY | 59356855 | 59356955 | - | 0.3877207561218887 | 9966373 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356865 | 59356965 | - | 0.4007557656399032 | 9907364 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356932 | 59357032 | - | 0.33799123310907786 | 9978653 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356980 | 59357080 | - | 0.055686136451676305 | 9994845 | 8502533 | 1.182153891322546 | 4 |
# +--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------+
# Stranded PyRanges object has 606,212 rows and 9 columns from 24 chromosomes.
# For printing, the PyRanges was sorted on Chromosome and Strand.
没有,但它可以很容易地与熊猫分类。我认为这会对“合并”部分有所帮助,对吗?在您的输出数据帧示例中,您是指以“25”而不是“20”结尾的第一行吗?是的,我是这样做的。编辑:)我想你编辑错单元格了!我希望对第二个数据帧的第一行进行编辑,以指示范围1(开始)到25(结束)。我不理解df.end.shift()-df.start).lt(0).cumsum()的部分。你能解释一下吗?这似乎对解决我的问题至关重要problem@Praderas检查重叠圈,例如[1,10]和[5,15],我们通过5@Praderas在这种情况下,你想合并头2还是尾2?(它将被视为一个区间并合并3),因为你提到这种情况,我认为你需要澄清在一些有嵌套间隔的情况下这是行不通的,例如<代码> [[ 1, 10 ],[2, 3 ],[5, 6 ] ] /代码>将被分组为<代码> [[1, 3 ],[5, 6 ] ] /代码>。如@根所指出的,被接受的解决方案是误导的。尝试:
df=pd.DataFrame({'chrom':['chr1','chr1','chr1','chr1','chr1','start':[1,2,5],'end':[10,3,6],'probability':[0.99,0.99,0.99],'read':[read1','read2','read3']}
df groupby((df end.shift()-df.start).lt(0.cumsum()).agg('chrom':'first','start','first','read','first','first','read','first','resume','resume':'resume','resume')
@Praderas对于大型数据集,我的回答速度提高了(可能)>100倍。此外,您接受的回答在一般情况下是错误的,因为它只考虑成对的行。OP给出的输入df
中的列集群
在哪里?试图理解您的答案它是由函数gr.cluster()
:)生成的
def praderas(df):
grpby = df.groupby("Cluster")
prob = grpby.probability.sum()
prob.name = "ProbSum"
n = grpby.read.count()
n.name = "Count"
return df.merge(prob, on="Cluster").merge(n, on="Cluster")
%time result = gr.cluster().apply(praderas)
# 11.4s !
result[result.Count > 2]
# +--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------+
# | Chromosome | Start | End | Strand | probability | read | Cluster | ProbSum | Count |
# | (category) | (int32) | (int32) | (category) | (float64) | (int64) | (int32) | (float64) | (int64) |
# |--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------|
# | chr1 | 52952 | 53052 | + | 0.7411051557901921 | 59695 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 52959 | 53059 | + | 0.9979036360671423 | 356518 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 53029 | 53129 | + | 0.47409221639405397 | 104776 | 70 | 2.2131010082513884 | 3 |
# | chr1 | 64657 | 64757 | + | 0.32465233067499366 | 386140 | 88 | 1.3880589602361695 | 3 |
# | ... | ... | ... | ... | ... | ... | ... | ... | ... |
# | chrY | 59356855 | 59356955 | - | 0.3877207561218887 | 9966373 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356865 | 59356965 | - | 0.4007557656399032 | 9907364 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356932 | 59357032 | - | 0.33799123310907786 | 9978653 | 8502533 | 1.182153891322546 | 4 |
# | chrY | 59356980 | 59357080 | - | 0.055686136451676305 | 9994845 | 8502533 | 1.182153891322546 | 4 |
# +--------------+-----------+-----------+--------------+----------------------+-----------+-----------+--------------------+-----------+
# Stranded PyRanges object has 606,212 rows and 9 columns from 24 chromosomes.
# For printing, the PyRanges was sorted on Chromosome and Strand.