[R] Character (1a, 1b) to numeric

[Richard O'Keefe]

This can be done very simply because vectors in R can have
named elements, and can be indexed by strings.

> stage <- c("1" = 1, "1a" = 1.3, "1b" = 1.5, "1c" = 1.7,
+            "2" = 2, "2a" = 2.3, "2b" = 2.5, "2c" = 2.7,
+            "3" = 3, "3a" = 3.3, "3b" = 3.5, "3c" = 3.7)

> testdata <- rep(c("1", "1a", "1b", "1c",
+                   "2", "2a", "2b", "2c",
+                   "3", "3a", "3b", "3c"), times=c(1:6,6:1))

> stage[testdata]
  1  1a  1a  1b  1b  1b  1c  1c  1c  1c   2   2   2   2   2  2a  2a  2a  2a
 2a
1.0 1.3 1.3 1.5 1.5 1.5 1.7 1.7 1.7 1.7 2.0 2.0 2.0 2.0 2.0 2.3 2.3 2.3 2.3
2.3
 2a  2b  2b  2b  2b  2b  2b  2c  2c  2c  2c  2c   3   3   3   3  3a  3a  3a
 3b
2.3 2.5 2.5 2.5 2.5 2.5 2.5 2.7 2.7 2.7 2.7 2.7 3.0 3.0 3.0 3.0 3.3 3.3 3.3
3.5
 3b  3c
3.5 3.7

On Sat, 11 Jul 2020 at 05:51, Jean-Louis Abitbol <abitbol using sent.com> wrote:

> Dear All
>
> I have a character vector,  representing histology stages, such as for
> example:
> xc <-  c("1", "1a", "1b", "1c", "2", "2a", "2b", "2c")
>
> and this goes on to 3, 3a etc in various order for each patient. I do have
> of course a pre-established  classification available which does change
> according to the histology criteria under assessment.
>
> I would want to convert xc, for plotting reasons, to a numeric vector such
> as
>
> xn <- c(1, 1.3, 1.5, 1.7, 2, 2.3, 2.5, 2.7)
>
> Unfortunately I have no clue on how to do that.
>
> Thanks for any help and apologies if I am missing the obvious way to do it.
>
> JL
> --
> Verif30042020
>
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