[R] approxfun values

[e-letter]

Readers,

According to the help '?approxfun', the function can be used to obtain
the interpolated values. The following test was tried:

> testinterpolation<-read.csv('test.csv',header=FALSE)
> testinterpolation
    V1 V2
1   10  2
2   20 NA
3   30  5
4   40  7
5   50 NA
6   60 NA
7   70  2
8   80  6
9   90  9
10 100 NA
> testinterpolationvalues<-approxfun(testinterpolation,y=NULL)
> testinterpolationvalues
function (v)
.C(C_R_approxfun, as.double(x), as.double(y), as.integer(n),
    xout = as.double(v), as.integer(length(v)), as.integer(method),
    as.double(yleft), as.double(yright), as.double(f), NAOK = TRUE,
    PACKAGE = "stats")$xout
<bytecode: 0x33ffab84>
<environment: 0x34072eac>
> testinterpolationvalues<-approx(testinterpolation,y=NULL)
> testinterpolationvalues
$x
 [1] 10.00000 11.63265 13.26531 14.89796 16.53061 18.16327 19.79592 21.42857
 [9] 23.06122 24.69388 26.32653 27.95918 29.59184 31.22449 32.85714 34.48980
[17] 36.12245 37.75510 39.38776 41.02041 42.65306 44.28571 45.91837 47.55102
[25] 49.18367 50.81633 52.44898 54.08163 55.71429 57.34694 58.97959 60.61224
[33] 62.24490 63.87755 65.51020 67.14286 68.77551 70.40816 72.04082 73.67347
[41] 75.30612 76.93878 78.57143 80.20408 81.83673 83.46939 85.10204 86.73469
[49] 88.36735 90.00000

$y
 [1] 2.000000 2.244898 2.489796 2.734694 2.979592 3.224490 3.469388 3.714286
 [9] 3.959184 4.204082 4.448980 4.693878 4.938776 5.244898 5.571429 5.897959
[17] 6.224490 6.551020 6.877551 6.829932 6.557823 6.285714 6.013605 5.741497
[25] 5.469388 5.197279 4.925170 4.653061 4.380952 4.108844 3.836735 3.564626
[33] 3.292517 3.020408 2.748299 2.476190 2.204082 2.163265 2.816327 3.469388
[41] 4.122449 4.775510 5.428571 6.061224 6.551020 7.040816 7.530612 8.020408
[49] 8.510204 9.000000

How to obtain a vector consisting _only_ of the interpolated values?

It was expected that 'approx' would return both original and
interpolated values (which the above shows) and that 'approxfun' would
not show the original values.

--
r2151