R-language data file read/write

R language data storage and reading

1. First Use getwd () to get the current directory, and use setwd ("C:/Data") to set the current directory:

2.0 Data Storage: create data box D:

> D <-data. frame (OBS = C (1, 2, 3), treat = C ("A", "B", "A"), weight = C (2.3, Na, 9 ))

2.1 save as simple text:

> Write. Table (D, file = "C:/data/foo.txt", row. Names = F, quote = f)

2.2 Save As comma-separated text:

> Write.csv (D, file = "C:/data/foo.csv", row. Names = F, quote = f)

2.3 save as an R file:

> Save (D, file = "C:/data/Foo. RDATA ")

2.4 save a workspace image:

> Save. Image () = save (list = ls (all = true), file = ". RDATA ")

3.0 Data Reading: Read functions include: Read. Table (), scan (), read. fwf ().

3.1 Use read. Table () to read houses. dat under "C: \ data:

> Setwd ("C:/Data"); houseprice <-read. Table (file = "houses. dat ")

If the first row of data is specified as the header, use the header option:

> Houseprice <-read. Table ("houses. dat", header = true)

Read. table () Deformation: aread.csv (Region, read.csv 2 (), read. delim (), read. delim2 (). the first two read the comma-separated data, and the last two read other delimiter data.

3.2 use scan () is more flexible than read. Table. However, you must specify the variable type, for example, C: \ data. DAT:

M 65 168

M 70 172

F 54 156

F 58 163

> Mydata <-scan ("data. dat", what = List ("", 0, 0 ))

> Mydata <-scan ("data. dat", what = List (sex = "", Weight = 0, Height = 0 ))

3.3 Use read. fwf () to read some fixed-width data in the file, for example, C: \ data \ data.txt:

A1.501.2

A1.551.3

B1.601.4

> Mydata <-read. fwf ("data.txt", widths = C (1, 4, 3), Col. names = C ("X", "Y", "Z "))

4.0 reading data in Excel format:

4.1 Use clipboard: Select Excel Data and copy it with Ctrl + C. In R, type the following command:

> Mydata <-read. delim ("Clipboard ")

4.2 UseProgramPackage rodbc. For example: C: \ data \ body.xls

Sex weight height

M 65 168

M 70 172

F 54 156

F 58 163

> Library (rodbc)

> Z <-odbcconnectexcel ("C:/data/body.xls ")

> Foo <-sqlfetch (Z, "sheet1 ")

> Close (z)

 

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