[R] replace items in vector with character based on logical operator

[Jeff Newmiller]

Your goal is fundamentally flawed,  since all elements of a vector must be if the same type. 
Create another vector to hold your character information. 

kc <- rep( 'NC', length( kx ) )
kc[ kx <= qt[[2]] ] <- 'DN'
kc[ kx >=qt [[4]] ] <- 'UP'

-- 
Sent from my phone. Please excuse my brevity.

On November 12, 2016 2:25:51 PM PST, Adrian Johnson <oriolebaltimore at gmail.com> wrote:
>Hi group,
>
>I have a vector of numeric items and I want to replace based on
>logical operator (> or <)  with 'up', 'down' or 'nochange'
>
>The way I am doing works sometimes and does not work sometime. I dont
>understand the problem. In this example, that works for condition DN
>first, gets over-written by UP and then by NC.
>
>
> I appreciate your help.
>Thanks
>Adrian
>
>In the example below (dput code given below).
>
>qt = quantile(kx)
>kx[kx <= qt[[2]]] <- 'DN'
>kx[kx >=qt [[4]]] <- 'UP'
>kx[kx < qt[[4]] | kx > qt[[2]]] <- 'NC'
>
>
>> qt
>       0%       25%       50%       75%      100%
> 9.341531  9.995026 10.186305 10.444237 11.013304
>
>> kx[kx <= qt[[2]]] <- 'DN'
>> kx
>      TCGA-3H-AB3K       TCGA-3H-AB3L       TCGA-3H-AB3M
>TCGA-3H-AB3O       TCGA-3H-AB3S       TCGA-3H-AB3T       TCGA-3H-AB3U
>     TCGA-3H-AB3X
>"11.0133035117116"               "DN" "10.2976687932597"
>"10.080008468093" "10.3661039885332"               "DN"
>"10.8971723299346" "10.0327245097586"
>      TCGA-3U-A98D       TCGA-3U-A98E       TCGA-3U-A98F
>TCGA-3U-A98G       TCGA-3U-A98H       TCGA-3U-A98I       TCGA-3U-A98J
>     TCGA-LK-A4NW
>"10.0094206497379" "10.4816534666287" "10.4317651665439"
>"DN" "10.2313364037012"               "DN" "10.1412738417844"
>     "DN"
>  TCGA-LK-A4NY       TCGA-LK-A4NZ       TCGA-LK-A4O0       TCGA-LK-A4O2
>"10.603941260297" "10.7959493941044" "10.0501324788234"
>"10.3877479259697"
>
>
>
>
>
>
>
>kx <- structure(c(11.0133035117116, 9.95184228858716, 10.2976687932597,
>10.080008468093, 10.3661039885332, 9.34153148077152, 10.8971723299346,
>10.0327245097586, 10.0094206497379, 10.4816534666287, 10.4317651665439,
>9.57711797674944, 10.2313364037012, 9.39562974544228, 10.1412738417844,
>9.80706011783492, 10.603941260297, 10.7959493941044, 10.0501324788234,
>10.3877479259697), .Names = c("TCGA-3H-AB3K", "TCGA-3H-AB3L",
>"TCGA-3H-AB3M", "TCGA-3H-AB3O", "TCGA-3H-AB3S", "TCGA-3H-AB3T",
>"TCGA-3H-AB3U", "TCGA-3H-AB3X", "TCGA-3U-A98D", "TCGA-3U-A98E",
>"TCGA-3U-A98F", "TCGA-3U-A98G", "TCGA-3U-A98H", "TCGA-3U-A98I",
>"TCGA-3U-A98J", "TCGA-LK-A4NW", "TCGA-LK-A4NY", "TCGA-LK-A4NZ",
>"TCGA-LK-A4O0", "TCGA-LK-A4O2"))
>
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