Question

我有一个文件，我想从中提取下面突出显示的两个值（Time，C_F [6]）。它在CentOS 7环境中，所以可以使用bash或gnuplot或r。我甚至不确定如何谷歌（例如从文件bash中提取值并没有真正提出解决方案）。可能吗？

我希望能够：

情节时间与C_F [6]
平均C_F [6]

编辑1：

我认为这可能就行，但它会重现整个文件 sed's /^.* C_F [6] = //'C_F.pressure＆gt; OUTPUTFILE

编辑2：

Extract of the file:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  3.0.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 3.0.0-6abec57f5449
Exec   : patchAverage p C_F -parallel
Date   : Apr 15 2017
Time   : 15:01:20
Host   : "login2.jjj.uk"
PID    : 59764
Case   : /nobackup/jjjj/Silsoe/Solid/solid_0_LES/motorBikeLES
nProcs : 8
Slaves :
7
(
"login2.jjjj.59765"
"login2.jjjj.59766"
"login2.jjjj.59767"
"login2.jjjj.59768"
"login2.jjjj.59769"
"login2.jjjj.59770"
"login2.jjjj.59771"
)

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0.18

Time = 0.18
    Reading volScalarField p
    Average of volScalarField over patch C_F[6] = -18.3176

Time = 0.19
    Reading volScalarField p
    Average of volScalarField over patch C_F[6] = -18.299

Time = 0.2
    Reading volScalarField p
    Average of volScalarField over patch C_F[6] = -18.2704

Time = 0.21
    Reading volScalarField p
    Average of volScalarField over patch C_F[6] = -18.2349

Answer 1

这是一种粗暴的做事方式：

# extract text from file line by line; will be indexed by line
sample <- readLines("D:\\tempFiles/example.txt")

# index the lines contaning "Time = "
timeI <- grep(x = sample, pattern = "Time = ")

# index the lines contaning "C_F[6]"; note that \\ is escape for [ and ]
C_FI <- grep(x = sample, pattern = "C_F\\[6\\]")

# extract lines and clean them
# note that these lines only contain "Time = values"; so just remove the "Time = "
timeval <-as.numeric(gsub(x = sample[timeI], pattern = "Time = ", replacement = ""))

# extract lines and clean them
# note that gsub removes all characters from te start (^) until "= "
C_FIval <- as.numeric(gsub(x = sample[C_FI], pattern = "^.*= ", ""))


# plot timve vs CF[6]
plot(y = timeval, x = C_FIval )

# get the mean
mean(C_FIval)

正则表达式还有更优雅的方法，但我仍然找到了解决这个问题的方法。这应该是一种基本方式。

从文件中提取值并取平均值

1 个答案: