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The regression problem Friedman 3 as described in Friedman (1991) and Breiman (1996). Inputs are 4 independent variables uniformly distributed over the ranges $$0 \le x1 \le 100$$ $$40 \pi \le x2 \le 560 \pi$$ $$0 \le x3 \le 1$$ $$1 \le x4 \le 11$$ The outputs are created according to the formula $$\mbox{atan}((x2 x3 - (1/(x2 x4)))/x1) + e$$ where e is \(N(0,sd^2)\).

Usage

sim_Friedman3(n, sd = 0.1)

Arguments

n

number of data points to create

sd

Standard deviation of noise. The default value of 125 gives a signal to noise ratio (i.e., the ratio of the standard deviations) of 3:1. Thus, the variance of the function itself (without noise) accounts for 90% of the total variance.

Value

Returns a list with components

x

input values (independent variables)

y

output values (dependent variable)

References

Breiman, Leo (1996) Bagging predictors. Machine Learning 24, pages 123-140.
Friedman, Jerome H. (1991) Multivariate adaptive regression splines. The Annals of Statistics 19 (1), pages 1-67.

See also

Other bark simulation functions: sim_Friedman1(), sim_Friedman2(), sim_circle()

Other bark functions: bark(), bark-package, bark-package-deprecated, sim_Friedman1(), sim_Friedman2(), sim_circle()

Examples

sim_Friedman3(n=100, sd=0.1)
#> $x
#>             [,1]      [,2]        [,3]      [,4]
#>   [1,] 30.825952 1127.9017 0.573424780  1.478231
#>   [2,] 56.282889 1152.0600 0.870915000  2.033601
#>   [3,] 10.283905  413.8673 0.921000510  2.241561
#>   [4,] 86.429125 1104.0521 0.973211584  6.799358
#>   [5,] 37.058717 1020.2058 0.565367990  2.493783
#>   [6,] 56.669640 1049.0497 0.580058141  4.571176
#>   [7,] 85.620612 1074.8537 0.451348698  8.135946
#>   [8,] 93.787521  137.4751 0.749643839  1.383408
#>   [9,] 57.649304  523.8623 0.534890170  8.120493
#>  [10,] 96.398831  295.6232 0.395163982  4.895550
#>  [11,] 94.458449  410.7939 0.594093726  8.949516
#>  [12,] 96.417692 1493.8341 0.346676224  4.511120
#>  [13,] 70.495891 1191.4955 0.203333060  4.434715
#>  [14,] 91.507220  496.2649 0.871611096  7.487752
#>  [15,] 65.914199 1447.5109 0.120421228  6.590462
#>  [16,] 70.462228  509.5219 0.254895523  6.631807
#>  [17,] 88.310760  707.1107 0.315147347  6.045018
#>  [18,] 27.884101  863.0375 0.673826131 10.039038
#>  [19,]  4.354110  562.6515 0.241721363  4.982203
#>  [20,] 99.230953  367.8261 0.718741739  4.130821
#>  [21,] 45.822133 1334.5513 0.105027412  4.170977
#>  [22,] 60.809732  145.8603 0.494299243  8.691526
#>  [23,] 84.767140  890.9077 0.059236672  8.451566
#>  [24,] 94.884000  839.6750 0.493812188  5.903832
#>  [25,]  1.986057  559.6768 0.250226249 10.288233
#>  [26,] 73.319807 1185.0692 0.891174042  5.008642
#>  [27,] 40.755611  649.4596 0.080101752  8.312420
#>  [28,] 41.391993  264.0161 0.017509584 10.617382
#>  [29,] 82.039428  804.2670 0.294779242  2.655079
#>  [30,] 17.574505  960.1463 0.817871663  5.938581
#>  [31,] 26.556426  298.4271 0.199264202  1.604306
#>  [32,]  3.464958  717.8549 0.441008693  5.314073
#>  [33,] 53.889174 1590.9096 0.213425233  2.594641
#>  [34,] 37.871453  259.6782 0.594987497  4.236741
#>  [35,] 89.704471  850.2740 0.932048126  5.143644
#>  [36,] 63.366214 1469.9975 0.090543105  7.923376
#>  [37,] 63.607036  194.8063 0.773080538  7.309777
#>  [38,] 66.784642  904.3950 0.720907238 10.137250
#>  [39,]  2.151921 1162.1605 0.853163768  9.627817
#>  [40,] 66.294452 1369.9562 0.240071075 10.613858
#>  [41,] 52.770047  390.6047 0.331604818  8.430682
#>  [42,] 76.327332 1201.1006 0.413337878  3.661946
#>  [43,] 26.010365  413.9119 0.514562150  9.632506
#>  [44,] 62.974862 1484.3180 0.143993061 10.936522
#>  [45,] 48.456779 1606.1559 0.028128325  9.897014
#>  [46,]  2.470620 1030.3406 0.083775715  2.060839
#>  [47,] 41.875079  669.4004 0.303986391  2.532628
#>  [48,] 19.881345  496.2695 0.218112098  8.412991
#>  [49,] 25.576360 1699.0529 0.305153707  2.291095
#>  [50,] 73.444774 1470.8927 0.338777487 10.828080
#>  [51,] 41.187703 1736.6659 0.509695614  8.165728
#>  [52,] 11.476699 1433.8945 0.367414622 10.002884
#>  [53,] 35.062301  407.1805 0.145373559  3.248528
#>  [54,]  1.898003 1559.2784 0.236825332  3.996812
#>  [55,] 53.919572 1456.4783 0.333344291  8.070362
#>  [56,] 71.965680  343.9097 0.544956580  1.677744
#>  [57,] 31.661532 1443.2678 0.221341793  9.818495
#>  [58,] 67.579770 1167.5540 0.347526818  4.580853
#>  [59,] 60.254614  316.3190 0.061869972  5.362826
#>  [60,] 54.028325  268.6651 0.983538146  6.689607
#>  [61,] 83.446984 1406.3700 0.232457852  1.697569
#>  [62,] 59.118330  646.0840 0.142002595  3.241725
#>  [63,] 49.596202 1448.2511 0.977395241  2.890007
#>  [64,] 10.458808 1525.4039 0.275599060  4.622639
#>  [65,] 44.228854  790.7129 0.944558017  3.884189
#>  [66,] 26.763161 1037.2351 0.444347145  2.409515
#>  [67,] 67.805727  476.5362 0.016627895 10.148604
#>  [68,] 82.057226 1040.8143 0.806981719  2.771745
#>  [69,] 30.498487 1095.2270 0.070730513  1.283073
#>  [70,] 72.519565 1489.9240 0.967027876  6.343249
#>  [71,] 88.149093 1745.3359 0.932933122  4.964997
#>  [72,] 88.459378  934.9048 0.596474341  8.683736
#>  [73,] 96.992085  989.8979 0.550144838  9.541985
#>  [74,] 77.908849 1570.3274 0.129840423  5.800195
#>  [75,] 84.016820 1518.6840 0.378134911  5.594849
#>  [76,] 21.680225 1390.7443 0.425370500  9.164034
#>  [77,] 31.560739  390.4897 0.830497077  1.909209
#>  [78,]  4.398040  231.3197 0.111564942  1.372887
#>  [79,] 54.870058  185.2058 0.472555966  4.651288
#>  [80,] 77.442946  280.1721 0.973888866  1.147488
#>  [81,] 48.996267  841.1061 0.436716406  5.406159
#>  [82,] 54.964301 1528.7694 0.294627368  8.299121
#>  [83,]  7.630711  779.2293 0.169721953  2.274610
#>  [84,] 88.413986 1573.9854 0.791205528  3.551065
#>  [85,] 33.834462 1218.1433 0.809181832  9.308088
#>  [86,]  6.441419 1707.2070 0.950115869  2.746835
#>  [87,] 29.304838 1675.8857 0.492245314  7.896159
#>  [88,] 62.641159  311.2145 0.460462597  5.304011
#>  [89,] 28.528188  874.4557 0.332182426  8.931595
#>  [90,]  8.386399  632.0582 0.676949844  2.974928
#>  [91,] 90.108014  281.6644 0.174675048 10.877295
#>  [92,] 44.483487  139.9396 0.838248761  1.742246
#>  [93,] 23.416390  427.4938 0.239468809  5.791856
#>  [94,] 23.394862  621.4651 0.816823635  9.557527
#>  [95,] 51.664437 1751.4432 0.143833089  1.410754
#>  [96,] 14.479299 1269.4888 0.370566186 10.354301
#>  [97,]  6.220333 1386.0282 0.956884115  6.977835
#>  [98,] 71.859516  159.7813 0.845859981  9.976063
#>  [99,] 62.156340  580.9319 0.881534312  4.899534
#> [100,] 28.626160  526.7528 0.005404439 10.791704
#> 
#> $y
#>   [1]  1.55845593  1.62135963  1.59164799  1.61660710  1.48245246  1.47342289
#>   [7]  1.43685486  0.89098999  1.21807163  0.87597717  1.12879908  1.28617670
#>  [13]  1.53598528  1.46310158  1.37315462  1.03143303  1.20409573  1.53340144
#>  [19]  1.71351951  1.06730746  1.12111759  0.90721157  0.56803291  1.17962792
#>  [25]  1.62668378  1.46015556  0.97394053  0.06614486  1.20770422  1.50682298
#>  [31]  1.05558016  1.60445814  1.50403672  1.23575106  1.35204559  1.00511700
#>  [37]  0.96651611  1.34832957  1.68724931  1.30338894  1.19250371  1.30944982
#>  [43]  1.41172915  1.16471093  0.84679889  1.54285974  1.33121444  1.24389417
#>  [49]  1.66624222  1.42276030  1.56724967  1.41478802  0.90886807  1.64581436
#>  [55]  1.32891832  1.23505317  1.48920327  1.24907667  0.16635414  1.53373651
#>  [61]  1.25920313  1.05295061  1.63704348  1.59548563  1.41427255  1.47576587
#>  [67] -0.02143759  1.47472971  1.10870813  1.63072137  1.68037500  1.41537110
#>  [73]  1.45999089  1.10667827  1.38693292  1.47071790  1.32485388  1.21269998
#>  [79]  1.09013858  1.33708294  1.58307448  1.45902861  1.47930360  1.51566074
#>  [85]  1.67539290  1.48119998  1.51055379  1.11524523  1.57217760  1.51152985
#>  [91]  0.64790509  1.19435007  1.60345166  1.51104608  1.40353431  1.55342898
#>  [97]  1.50222820  1.00186983  1.39480412  0.24371478
#>