R-helpers

 

I have 120 small Excel sheets to read and I am using
library(xlsReadWrite): one example below.

 

I had hoped to read sheets by looping over a list of numbers in their
name (eg Book1.xls, Book2.xls, etc).

 

I thought I had seen examples which used eval-parse-paste in this way. 

 

However, I have not been able to get it to work..

 

1. is this a feasible approach?

 

2. if not advice would be welcome.

 

3. Equally, advice about a better approach would also be v. welcome.

 

I haven't included the data because my failed attempt is
data-independent (and probably more basic).  

 

 

Michael Anyadike-Danes

 

############# show that read.xls works

 

> test <- read.xls("Book1.xls",sheet=1,from=4,colClasses="numeric")

> str(test)

'data.frame':   23 obs. of  13 variables:

 $ Off.Flows..Thousands.: num  117.19    NaN     NA   1.43   2.26 ...

 $ Off.Flows..Thousands.: num  8.42 NaN NA 0.08 0.11 0.01 0.11 1.59 0.16
0.04 ...

 $ Off.Flows..Thousands.: num  20 NaN NA 0.2 0.3 0.02 0.32 4.39 0.41
0.11 ...

 $ Off.Flows..Thousands.: num  12.36   NaN    NA  0.14  0.27 ...

 $ Off.Flows..Thousands.: num  7.59 NaN NA 0.11 0.18 0.01 0.14 1.46 0.23
0.06 ...

 $ Off.Flows..Thousands.: num  10.31   NaN    NA  0.12  0.23 ...

 $ Off.Flows..Thousands.: num  7.55 NaN NA 0.08 0.2 0.01 0.11 1.6 0.23
0.05 ...

 $ Off.Flows..Thousands.: num  10.57   NaN    NA  0.19  0.21 ...

 $ Off.Flows..Thousands.: num  9.36 NaN NA 0.13 0.26 0.02 0.13 2.12 0.27
0.07 ...

 $ Off.Flows..Thousands.: num  8.21 NaN NA 0.1 0.19 0.01 0.1 1.9 0.23
0.06 ...

 $ Off.Flows..Thousands.: num  9.04 NaN NA 0.13 0.11 0.01 0.17 1.54 0.17
0.05 ...

 $ Off.Flows..Thousands.: num  13.42   NaN    NA  0.14  0.19 ...

 $ Off.Flows..Thousands.: num  0.37 NaN NA NaN 0.01 NaN 0.01 0.05 0.02
NaN ...

 

############### simple minded attempt substituting eval-parse-paste

 

> nam <- 1

 

> test <-
eval(parse(paste('read.xls("Book',nam,'.xls",sheet=1,from=4,colClasses="
numeric")',sep='')))

Error in file(file, "r") : unable to open connection

In addition: Warning message:

In file(file, "r") :

  cannot open file
'read.xls("Book1.xls",sheet=1,from=4,colClasses="numeric")', reason
'Invalid argument'

 

############### stripping off eval, looking for clues

 

>
parse(paste('read.xls("Book',nam,'.xls",sheet=1,from=4,colClasses="numer
ic")',sep=''))

Error in file(file, "r") : unable to open connection

In addition: Warning message:

In file(file, "r") :

  cannot open file
'read.xls("Book1.xls",sheet=1,from=4,colClasses="numeric")', reason
'Invalid argument'

 

############### stripping off parse, still looking for clues

 

>
paste('read.xls("Book',nam,'.xls",sheet=1,from=4,colClasses="numeric")',
sep='')

[1] "read.xls(\"Book1.xls\",sheet=1,from=4,colClasses=\"numeric\")"

 

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