Convert FIX message format ("Tag = Value") to CSV

I have a csv / log file of 35 = S (Quote messages; "Tag = Value") and I need to extract the bids to the correct CSV file for data mining. This is not strictly FIX-related, but rather an R-related question about how to clear a dataset.

The raw messages look something like this:

190=1.1204 ,191=-0.000029,193=20141008,537=0        ,631=1.12029575,642=0.000145,10=56
190=7.20425,191=0.000141 ,537=0       ,631=7.2034485,10=140        ,            ,
190=1.26237,191=0        ,537=1       ,10=068       ,              ,            ,

      

I need to first go to an intermediate dataset that looks like this when the same tags are aligned.

190=1.1204 ,191=-0.000029,193=20141008,537=0,631=1.12029575,642=0.000145,10=56
190=7.20425,191=0.000141 ,            ,537=0,631=7.2034485 ,            ,10=140
190=1.26237,191=0        ,            ,537=1,              ,            ,10=068

      

which in turn would need to be converted to this:

190    ,191      ,193     ,537,631       ,642     ,10
1.1204 ,-0.000029,20141008,0  ,1.12029575,0.000145,56
7.20425,0.000141 ,        ,0  ,7.2034485 ,        ,140
1.26237,0        ,        ,1  ,          ,        ,068

      

I'm in the middle of developing a bash script with awk, but I'm wondering if I can do this in R. Currently, my biggest challenge is getting to the staging table. From the intermediate to the final table, I was thinking about using R with the tidyr package, specifically the "separate" function. If anyone can suggest a better logic I would greatly appreciate it!

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2 answers


Another possibility. Start with the same scan

as @Andrie, but also use arguments strip.white

and na.strings

:

x <- scan(text = "190=1.1204 ,191=-0.000029,193=20141008,537=0        ,631=1.12029575,642=0.000145,10=56
190=7.20425,191=0.000141 ,537=0       ,631=7.2034485,10=140        ,            ,
190=1.26237,191=0        ,537=1       ,10=068       ,              ,            ,",
           sep = ",",
           what = "character", 
           strip.white = TRUE,
           na.strings = "")

# remove NA
x <- x[!is.na(x)]

      

Then use colsplit

and dcast

from the reshape2

package:

library(reshape2)

# split 'x' into two columns
d1 <- colsplit(string = x, pattern = "=", names = c("x", "y")) 

# create an id variable, needed in dcast
d1$id <- ave(d1$x, d1$x, FUN = seq_along)   

# reshape from long to wide
d2 <- dcast(data = d1, id ~ x, value.var = "y")

#   id  10     190       191      193 537      631      642
# 1  1  56 1.12040 -0.000029 20141008   0 1.120296 0.000145
# 2  2 140 7.20425  0.000141       NA   0 7.203449       NA
# 3  3  68 1.26237  0.000000       NA   1       NA       NA

      



Because you mentioned tidyr

:

library(tidyr)
d1 <- separate(data = data.frame(x), col = x, into = c("x", "y"), sep = "=")
d1$id <- ave(d1$x, d1$x, FUN = seq_along)
spread(data = d1, key = x, value = y)
#   id  10     190       191      193 537        631      642
# 1  1  56  1.1204 -0.000029 20141008   0 1.12029575 0.000145
# 2  2 140 7.20425  0.000141     <NA>   0  7.2034485     <NA>
# 3  3 068 1.26237         0     <NA>   1       <NA>     <NA>

      

This stores the values ​​as character

. If you want numeric

, you can install convert = TRUE

in spread

.

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By the editors. Complete solution using only basic R functions:

dat <- scan(sep=",", what="character", text="190=1.1204 ,191=-0.000029,193=20141008,537=0        ,631=1.12029575,642=0.000145,10=56
190=7.20425,191=0.000141 ,537=0       ,631=7.2034485,10=140        ,            ,
190=1.26237,191=0        ,537=1       ,10=068       ,              ,            ,")

dat <- gsub(" ", "", dat)
dat <- dat[dat != ""]

x <- as.data.frame(
  matrix(
    unlist(
      sapply(dat, strsplit, split = "=", USE.NAMES=FALSE)
    ),
    ncol=2, byrow=TRUE
  )
)

z <- unstack(x, V2 ~ V1)

      

The resulting object is a named list that is close to what you wanted. You will need to do some extra work to convert this to a matrix, if necessary.

$`10`
[1] "56"  "140" "068"

$`190`
[1] "1.1204"  "7.20425" "1.26237"

$`191`
[1] "-0.000029" "0.000141"  "0"   

....
etc.     

      



Here you just need to insert a list with the appropriate number of NA values:

maxLength <- max(sapply(z, length))
sapply(z, function(x)c(as.numeric(x), rep(NA, maxLength - length(x))))

      

gives:

      10     190       191      193 537      631      642
[1,]  56 1.12040 -0.000029 20141008   0 1.120296 0.000145
[2,] 140 7.20425  0.000141       NA   0 7.203449       NA
[3,]  68 1.26237  0.000000       NA   1       NA       NA

      

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