# [R] several "ifelse" problems...

Patrizio Frederic frederic.patrizio at gmail.com
Mon Feb 16 20:04:43 CET 2009

```do you mean:

f=function(x) 0*(abs(x-.5)<=.3)-1*(abs(x-.5)>=.4)+(10*x-2)*(x>.1&x<.2)+(-10*x+8)*(x>=.2&x<=.5)
f(x)
curve(f,0,1)

hope it helps.

Patrizio

2009/2/14 kathie <kathryn.lord2000 at gmail.com>:
>
> Dear R users,
>
> >From the code below, I try to compute "y" value. (In fact, y looks like a
> trapezoid)
>
> ------------------------------------------------------------------
>
> x <- seq(0,1,.01)
> y <- ifelse(abs(x-.5)<=0.3,0,
>            ifelse(abs(w-.5)>=0.4,-1,
>                   ifelse((0.1<w && w<0.2),10*x-2,-10*x+8)))
>
> ------------------------------------------------------------------
>
> So, results are...
>
> ------------------------------------------------------------------
>> x
>  [1] 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13
> 0.14
>  [16] 0.15 0.16 0.17 0.18 0.19 0.20 0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28
> 0.29
>  [31] 0.30 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.40 0.41 0.42 0.43
> 0.44
>  [46] 0.45 0.46 0.47 0.48 0.49 0.50 0.51 0.52 0.53 0.54 0.55 0.56 0.57 0.58
> 0.59
>  [61] 0.60 0.61 0.62 0.63 0.64 0.65 0.66 0.67 0.68 0.69 0.70 0.71 0.72 0.73
> 0.74
>  [76] 0.75 0.76 0.77 0.78 0.79 0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88
> 0.89
>  [91] 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1.00
>
>> y
>  [1] -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1  8  8  8  8  8  8  8  8  8  0  0  0
> 0  0
>  [26]  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
> 0  0
>  [51]  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
> 0  0
>  [76]  0  0  0  0  0  8  8  8  8  8  8  8  8  8  8 -1 -1 -1 -1 -1 -1 -1 -1
> -1 -1
> [101] -1
>>
>
> ------------------------------------------------------------------
>
> However, even though the results show that y=8 for x=0.11, when x=0.11,
> actual y value is -0.9.  And, y=-0.8 for x=0.88.  I cannot understand the
> above results.
>
> Any comments will be greatly appreciated.
>
> Kathryn Lord
> --
> View this message in context: http://www.nabble.com/several-%22ifelse%22-problems...-tp22009321p22009321.html
> Sent from the R help mailing list archive at Nabble.com.
>
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