# [R] if else condition - help

WRAY NICHOLAS nicholas.wray at ntlworld.com
Sun May 22 20:12:25 CEST 2016

```Hi Adrian I'm not sure that you need to use the ifelse here.  You can simply
assign values ina vector or matrix using a simple condition -- here is a simple
example:

v<-c(4,5,6,7)
v1<-v
v1[]<-0
v1[v<5]<--1
v1[v>6]<-1
v1

Nick

>
>     On 22 May 2016 at 18:58 Adrian Johnson <oriolebaltimore at gmail.com> wrote:
>
>
>     Hi group:
>     I am having difficulty with if else condition. I kindly request some help.
>
>     I have a matrix k
>
>     > k
>     C1 C2 C3 C4
>     A 0.09902175 -0.1083887 0.2018689 -0.3546167
>     B 1.60623838 -1.4167034 0.9076373 -0.3161138
>     C -0.10433133 -1.7060911 -0.4030050 1.0153297
>     D -2.91485614 2.9201895 -2.4771802 -2.6991517
>
>     I want to convert values > 1.5 to 1, < -1.5 to -1 and rest to 0;
>
>     > k1 - desired output
>     C1 C2 C3 C4
>     A 0 0 0 0
>     B 1 0 0 0
>     C 0 -1 0 0
>     D -1 1 -1 -1
>
>
>     I am trying with if else but cannot do it. I could only define one
>     condition. Could someone help how I can do this. I dont mean only if
>     else, but any other way.
>
>     k =
>     structure(c(0.0990217544905328, 1.60623837694539, -0.104331330281166,
>     -2.91485614212114, -0.108388742328104, -1.41670341534772,
> -1.70609114096417,
>     2.92018951284015, 0.201868946570178, 0.907637296638577,
> -0.403004972105994,
>     -2.47718015803221, -0.354616729237253, -0.316113789733413,
> 1.01532974064126,
>     -2.69915170731852), .Dim = c(4L, 4L), .Dimnames = list(c("A",
>     "B", "C", "D"), c("C1", "C2", "C3", "C4")))
>
>
>
>     k1 <- t(apply(k, 1, function(x) ifelse(x > 1.5,1,-1)))
>
>     > k1
>     C1 C2 C3 C4
>     A -1 -1 -1 -1
>     B 1 -1 -1 -1
>     C -1 -1 -1 -1
>     D -1 1 -1 -1
>
>
>
>     Thanks
>
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