Create Initial Sample

Convenient helper function, which creates an initial sample - either based on random (uniform) sampling or using latin hypercube sampling.

createInitialSample(n.obs, dim, control)

Arguments

n.obs	[integer(1)] Number of observations.
dim	[integer(1)] Number of dimensions.
control	[list] Control argument. For further information refer to the details.

Value

[matrix]. A matrix, consisting of n.obs rows of dim-dimensional observations.

Details

Per default, this function will produce n.obs observations of size dim in the range from 0 to 1. If you want to create a more specific initial sample, the following control arguments might be helpful:

• init_sample.type: Should the initial sample be created based on random uniform sampling ("random") or on a latin hypercube sample ("lhs")? The default is "random".

• init_sample.lower: The lower bounds of the initial sample. Either a vector of size dim or a scalar (if all lower bounds are identical). The default is 0.

• init_sample.upper: The upper bounds of the initial sample. Either a vector of size dim or a scalar (if all upper bounds are identical). The default is 1.

Examples

# (1) create a simple initial sample:
X = createInitialSample(300, 5)
summary(X)
#>        V1                  V2                 V3                 V4           
#>  Min.   :0.0009579   Min.   :0.002401   Min.   :0.008509   Min.   :0.0006031  
#>  1st Qu.:0.2429917   1st Qu.:0.245017   1st Qu.:0.253667   1st Qu.:0.2406380  
#>  Median :0.4928397   Median :0.492408   Median :0.482884   Median :0.4880612  
#>  Mean   :0.4993741   Mean   :0.495573   Mean   :0.500302   Mean   :0.4919303  
#>  3rd Qu.:0.7380544   3rd Qu.:0.725750   3rd Qu.:0.759592   3rd Qu.:0.7402251  
#>  Max.   :0.9964129   Max.   :0.995568   Max.   :0.996453   Max.   :0.9970272  
#>        V5          
#>  Min.   :0.005146  
#>  1st Qu.:0.233525  
#>  Median :0.467263  
#>  Mean   :0.477459  
#>  3rd Qu.:0.722433  
#>  Max.   :0.999062  

# (2) create a more specific initial sample:
ctrl = list(init_sample.type = "lhs",
  init_sample.lower = c(-5, 2, 0),
  init_sample.upper = 10)
X = createInitialSample(200, 3, control = ctrl)
summary(X)
#>        V1               V2               V3          
#>  Min.   :-4.945   Min.   : 2.016   Min.   :0.007931  
#>  1st Qu.:-1.222   1st Qu.: 4.001   1st Qu.:2.517489  
#>  Median : 2.512   Median : 6.010   Median :4.988256  
#>  Mean   : 2.500   Mean   : 6.001   Mean   :5.000196  
#>  3rd Qu.: 6.244   3rd Qu.: 7.989   3rd Qu.:7.495977  
#>  Max.   : 9.927   Max.   :10.000   Max.   :9.954831