[R] replace character by numeric value

[arnaud gaboury]

On Thu, Sep 28, 2023 at 8:18 AM Ivan Calandra <ivan.calandra using leiza.de> wrote:
>
> Dear Arnaud,
>
> I don't quite unterstand why you have imbricated ifelse() statements. Do
> you have more that BUY (1) and SELL (-1)? If not, why not simply:
> mynewdf2 <- mydf2 |> dplyr::mutate(side = ifelse(side == 'BUY', 1, -1))

Yes it works indeed.
I found another solution :
df <- df |> mutate(side = as.numeric(ifelse(side == 'BUY', 1,
ifelse(side == 'SELL', -1, side))))
but yours is much simpler. and I can use dplyr::if_else() or
fifelse(). which looks safer and faster.

>
> That would solve the problem. I'm not quite sure exactly what happens,
> but this is probably related to the intermediary result after the first
> ifelse(), where characters and numeric are mixed. But conversion to
> numeric works properly, so I'm not sure what you meant:
> as.numeric(mynewdf2$side)
>
> More generally, why are you trying to convert to 1 and -1?

I am working on a crypto asset portfolio and want to compute profit &
loss. To achieve it, I need to convert (BUY * quantity) to quantity
and
(SELL * quantity) to -quantity.

Thank you for your answer.

Why not use
> factors? Are you trying to test contrasts maybe? I would be surprised if
> the function for the statistical test you are trying to use does not
> deal with that already on its own.
>
> HTH,
> Ivan
>
>
> On 27/09/2023 13:01, arnaud gaboury wrote:
> > I have two data.frames:
> >
> > mydf1 <- structure(list(symbol = "ETHUSDT", cummulative_quote_qty =
> > 1999.9122, side = "BUY", time = structure(1695656875.805, tzone = "", class
> > = c("POSIXct", "POSIXt"))), row.names = c(NA, -1L), class = c("data.table",
> > "data.frame"))
> >
> > mydf2 <- structure(list(symbol = c("ETHUSDT", "ETHUSDT", "ETHUSDT"),
> > cummulative_quote_qty = c(1999.119408,
> > 0, 2999.890985), side = c("SELL", "BUY", "BUY"), time =
> > structure(c(1695712848.487,
> > 1695744226.993, 1695744509.082), class = c("POSIXct", "POSIXt"
> > ), tzone = "")), row.names = c(NA, -3L), class = c("data.table",
> > "data.frame"))
> >
> > I use this line to replace 'BUY' by numeric 1 and 'SELL' by numeric -1 in
> > mydf1 and mydf2:
> > mynewdf <- mydf |> dplyr::mutate(side = ifelse(side == 'BUY', 1,
> > ifelse(side == 'SELL', -1, side)))
> >
> > This does the job but I am left with an issue: 1 and -1 are characters for
> > mynewdf2 when it is numeric for mynewdf1. The result I am expecting is
> > getting numeric values.
> > I can't solve this issue (using as.numeric(1) doesn't work) and don't
> > understand why I am left with num for mynewdf1 and characters for mynewdf2.
> >
> >> mynewdf1 <- mydf1 |> dplyr::mutate(side = ifelse(side == 'BUY', 1,
> > ifelse(side == 'SELL', -1, side)))
> >> str(mynewdf1)
> > Classes ‘data.table’ and 'data.frame': 1 obs. of  4 variables:
> >   $ symbol               : chr "ETHUSDT"
> >   $ cummulative_quote_qty: num 2000
> >   $ side                 : num 1      <<<------
> >   $ time                 : POSIXct, format: "2023-09-25 17:47:55"
> >   - attr(*, ".internal.selfref")=<externalptr>
> >
> >> mynewdf2 <- mydf2 |> dplyr::mutate(side = ifelse(side == 'BUY', 1,
> > ifelse(side == 'SELL', -1, side)))
> >>   str(mynewdf2)
> > Classes ‘data.table’ and 'data.frame': 3 obs. of  4 variables:
> >   $ symbol               : chr  "ETHUSDT" "ETHUSDT" "ETHUSDT"
> >   $ cummulative_quote_qty: num  1999 0 3000
> >   $ side                 : chr  "-1" "1" "1"   <<<------
> >   $ time                 : POSIXct, format: "2023-09-26 09:20:48"
> > "2023-09-26 18:03:46" "2023-09-26 18:08:29"
> >   - attr(*, ".internal.selfref")=<externalptr>
> >
> > Thank you for help
> >
> >       [[alternative HTML version deleted]]
> >
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> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.