CODEWITHSUNDEEP
r
Kamil
Kamil

Reputation: 183

Converting a string to a table in R

I'm completely new to R and I'm making a program that will solve a system of equations from a string like for example this:

my_string <- "3x+2y=0; -1x+4y=-1; 13x-2y=11"

and only one thing prevents me from finishing it.

After some replace instructions I could obtain this string:

my_string <- "3, 2, 0, -1, 4, -1, 13, -2, 11"

I want to build a 3*3 table but can't manage to turn this string into a form which would enable me to do so (a vector). I've tried with data.frame, as.numeric, lapply, noquote and other functions but couldn't find an answer.

The result should be :

x <- matrix(c(my_string), ncol=3,nrow=3,byrow=TRUE)

x

#    [,1]   [,2]   [,3]

# [1,] 3     2      0

# [2,]-1     4     -1

# [3,]13    -2     11

Thank you in advance.

Upvotes: 0

Views: 124

Answers (2)

Ista
Ista

Reputation: 10437

You can use scan to parse delimited values in a file or character vector. 

matrix(scan(text = my_string, sep = ",", what = 1L), ncol = 3, byrow = TRUE)
#Read 9 items
#     [,1] [,2] [,3]
#[1,]    3    2    0
#[2,]   -1    4   -1
#[3,]   13   -2   11

Upvotes: 1

MrFlick
MrFlick

Reputation: 206197

You should user strsplit to split based on commas and then turn those into numeric values

vals <- as.numeric(strsplit(my_string, ",")[[1]])
x <- matrix(vals, ncol=3,nrow=3,byrow=TRUE)
x
#      [,1] [,2] [,3]
# [1,]    3    2    0
# [2,]   -1    4   -1
# [3,]   13   -2   11

Upvotes: 0

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