Function for computing standard SO-PLS based on the interface of the pls package.

sopls(
  formula,
  ncomp,
  max_comps = min(sum(ncomp), 20),
  data,
  subset,
  na.action,
  scale = FALSE,
  validation = c("none", "CV", "LOO"),
  sequential = FALSE,
  segments = 10,
  sel.comp = "opt",
  progress = TRUE,
  ...
)

Arguments

formula

Model formula accepting a single response (block) and predictor block names separated by + signs.

ncomp

Numeric vector of components per block or scalar of overall maximum components.

max_comps

Maximum total number of components from all blocks combined (<= sum(ncomp)).

data

The data set to analyse.

subset

Expression for subsetting the data before modelling.

na.action

How to handle NAs (no action implemented).

scale

Logical indicating if variables should be scaled.

validation

Optional cross-validation strategy "CV" or "LOO".

sequential

Logical indicating if optimal components are chosen sequentially or globally.

segments

Optional number of segments or list of segments for cross-validation. (See [pls::cvsegments()]).

sel.comp

Character indicating if sequential optimal number of components should be chosen as minimum RMSECV ('opt', default) or by Chi-square test ('chi').

progress

Logical indicating if a progress bar should be displayed while cross-validating.

...

Additional arguments to underlying methods.

Value

An sopls, mvr object with scores, loadings, etc. associated with printing (sopls_results) and plotting methods (sopls_plots).

Details

SO-PLS is a method which handles two or more input blocks by sequentially performing PLS on blocks against a response and orthogonalising the remaining blocks on the extracted components. Component number optimisation can either be done globally (best combination across blocks) or sequentially (determine for one block, move to next, etc.).

References

Jørgensen K, Mevik BH, Næs T. Combining designed experiments with several blocks of spectroscopic data. Chemometr Intell Lab Syst. 2007;88(2): 154–166.

See also

SO-PLS result functions, sopls_results, SO-PLS plotting functions, sopls_plots, SO-PLS Måge plot, maage, and SO-PLS path-modelling, SO_TDI. Overviews of available methods, multiblock, and methods organised by main structure: basic, unsupervised, asca, supervised and complex.

Examples

data(potato)
so <- sopls(Sensory ~ Chemical + Compression, data=potato, ncomp=c(10,10), 
            max_comps=10, validation="CV", segments=10)
summary(so)
#> Data: 	X dimension: 26 0 
#> 	Y dimension: 26 9
#> Fit method: PKPLS
#> Number of components considered: 10
#> 
#> VALIDATION: RMSEP
#> Cross-validated using 10 random segments.
#>    0,0     0,1     0,2     0,3     0,4     0,5     0,6     0,7     0,8     0,9  
#> 1.1472  0.9974  1.1034  0.9942  1.0159  1.1523  1.0857  1.1834  1.2494  1.3022  
#>   0,10     1,0     1,1     1,2     1,3     1,4     1,5     1,6     1,7     1,8  
#> 1.2690  0.9058  0.8860  0.9779  0.9029  0.8942  0.9320  0.9441  1.0542  1.1243  
#>    1,9     2,0     2,1     2,2     2,3     2,4     2,5     2,6     2,7     2,8  
#> 1.1369  0.8077  0.7023  0.7124  0.7737  0.8072  0.8651  0.8511  0.9742  1.0048  
#>    3,0     3,1     3,2     3,3     3,4     3,5     3,6     3,7     4,0     4,1  
#> 0.7439  0.7275  0.7111  0.7716  0.8322  0.8846  0.8893  0.9793  0.7494  0.7165  
#>    4,2     4,3     4,4     4,5     4,6     5,0     5,1     5,2     5,3     5,4  
#> 0.7272  0.7748  0.8135  0.9157  0.9001  0.7752  0.7491  0.7593  0.8494  0.9693  
#>    5,5     6,0     6,1     6,2     6,3     6,4     7,0     7,1     7,2     7,3  
#> 1.0306  0.8504  0.8438  0.8198  0.9304  1.0222  0.8997  0.8910  0.8418  0.9632  
#>    8,0     8,1     8,2     9,0     9,1    10,0  
#> 1.0062  1.0033  0.9511  1.0682  1.0557  1.6371  
#> 
#> TRAINING: % variance explained
#>         0,0    0,1    0,2    0,3    0,4    0,5    0,6    0,7    0,8    0,9
#> X         0  45.87  55.51  62.90  66.46  67.73  74.95  78.26  79.85  82.39
#> ref       0  42.19  54.73  65.01  66.85  73.96  74.10  74.44  77.45  77.57
#> hard      0  39.11  41.97  42.23  43.80  50.95  54.87  56.78  59.50  74.53
#> firm      0  42.55  57.44  59.44  61.06  66.78  68.62  69.02  71.34  76.53
#> elas      0  38.64  65.31  73.51  75.63  77.23  79.25  81.19  83.71  86.57
#> adhes     0  16.13  18.11  26.71  26.74  29.70  42.07  44.57  46.47  46.54
#> grainy    0  23.21  43.78  62.23  64.02  67.18  67.72  69.83  74.79  74.79
#> mealy     0  35.35  41.99  57.36  58.84  67.17  70.33  73.21  77.77  78.88
#> moist     0  24.48  27.71  43.10  44.27  48.41  53.39  62.37  67.60  74.79
#> chewi     0  21.98  22.78  48.17  55.50  59.96  68.39  72.54  76.39  77.42
#>          0,10    1,0    1,1    1,2    1,3    1,4    1,5    1,6    1,7    1,8
#> X       83.18  34.20  64.12  71.71  76.24  78.20  79.49  83.37  84.42  85.59
#> ref     77.57  55.79  64.00  64.25  73.75  77.39  79.53  80.42  80.50  80.96
#> hard    75.43  24.10  41.42  44.05  44.07  44.09  47.61  53.70  53.86  62.46
#> firm    79.31  42.73  54.16  58.42  62.05  63.55  64.91  70.85  70.91  70.93
#> elas    88.14  53.24  59.32  63.95  71.43  74.51  75.33  77.16  78.86  78.88
#> adhes   54.68  17.49  22.70  33.54  33.75  34.70  34.90  39.43  48.51  48.92
#> grainy  74.82  57.69  58.26  58.39  71.89  75.95  76.07  76.72  77.73  79.00
#> mealy   79.25  61.37  65.64  66.70  74.33  75.36  77.44  78.35  79.55  80.15
#> moist   77.22  57.32  58.51  62.12  66.20  66.35  67.13  67.14  69.51  71.02
#> chewi   81.68  53.27  54.25  64.22  66.35  69.59  69.96  72.80  77.64  77.64
#>           1,9    2,0    2,1    2,2    2,3    2,4    2,5    2,6    2,7    2,8
#> X       86.07  42.76  72.61  79.40  81.41  82.69  84.98  88.16  88.87  89.84
#> ref     81.20  76.03  85.17  87.21  89.03  90.67  90.68  91.36  91.36  91.39
#> hard    69.98  25.29  44.10  46.63  46.63  46.88  52.03  61.89  64.48  73.84
#> firm    80.21  55.93  69.19  76.45  76.45  76.80  77.79  82.58  82.64  86.03
#> elas    87.63  63.10  70.21  78.03  78.08  78.17  80.37  82.19  84.54  85.69
#> adhes   49.97  34.43  39.48  46.70  46.78  48.48  54.50  56.16  67.45  72.74
#> grainy  79.50  83.95  84.78  87.19  88.01  88.56  89.28  89.29  89.30  89.49
#> mealy   80.19  81.14  85.67  85.68  87.94  88.28  88.57  89.15  89.69  90.49
#> moist   72.44  67.94  69.06  70.49  72.51  72.53  72.61  72.80  73.61  78.69
#> chewi   78.05  70.55  71.41  77.11  77.11  78.09  78.17  79.79  83.27  86.51
#>           3,0    3,1    3,2    3,3    3,4    3,5    3,6    3,7    4,0    4,1
#> X       63.76  78.59  84.55  86.77  87.73  90.09  91.81  92.46  70.09  80.35
#> ref     84.50  86.31  87.91  89.34  91.72  91.74  93.12  93.13  84.91  87.28
#> hard    29.51  45.43  50.00  50.23  51.56  54.69  61.12  63.12  30.80  49.39
#> firm    62.42  68.64  76.93  76.96  77.84  78.25  82.67  82.72  62.64  73.46
#> elas    69.44  70.75  78.04  78.06  78.07  80.60  82.75  85.36  69.94  73.16
#> adhes   34.51  46.88  50.83  51.04  51.60  57.45  58.26  69.10  64.76  65.66
#> grainy  87.18  87.45  88.87  89.86  90.34  91.06  91.37  91.45  87.20  87.21
#> mealy   84.89  86.14  86.18  88.32  89.25  89.48  91.02  91.95  88.83  88.96
#> moist   70.03  70.05  72.13  74.57  74.71  74.88  74.97  76.40  75.09  76.33
#> chewi   70.56  72.61  77.34  77.39  78.58  78.58  79.89  83.77  82.06  82.29
#>           4,2    4,3    4,4    4,5    4,6    5,0    5,1    5,2    5,3    5,4
#> X       87.12  88.89  89.78  92.03  93.37  75.21  84.27  91.16  92.52  93.47
#> ref     88.13  89.65  92.48  92.54  93.63  85.03  88.23  89.16  90.27  92.85
#> hard    49.95  50.65  50.76  54.96  60.99  41.38  53.88  54.08  54.33  54.70
#> firm    77.00  77.10  77.44  78.23  83.34  68.24  75.97  78.78  78.78  79.40
#> elas    78.98  79.09  79.43  82.78  83.85  72.35  74.56  79.87  80.48  80.91
#> adhes   67.28  68.26  69.21  70.41  70.90  64.77  65.81  67.35  67.83  69.01
#> grainy  89.07  90.46  91.63  92.15  92.30  87.53  87.56  89.67  90.98  91.93
#> mealy   88.99  93.13  94.52  94.64  95.00  89.21  89.65  89.73  93.45  94.51
#> moist   76.60  82.33  82.90  82.90  83.28  79.72  79.91  79.98  83.86  84.08
#> chewi   84.08  84.45  86.24  86.38  86.39  82.11  82.31  83.97  84.76  86.45
#>           5,5    6,0    6,1    6,2    6,3    6,4    7,0    7,1    7,2    7,3
#> X       95.40  77.28  86.22  93.18  94.55  95.63  79.57  88.43  95.46  96.65
#> ref     92.91  86.80  90.43  91.47  92.26  94.07  88.07  91.60  92.62  92.70
#> hard    60.53  45.27  56.94  57.05  57.64  59.71  45.28  56.91  56.99  57.22
#> firm    80.75  68.98  76.56  79.17  79.42  80.55  69.02  76.72  79.16  79.35
#> elas    83.34  72.55  74.96  80.08  80.15  80.26  73.76  76.39  81.36  81.61
#> adhes   70.53  64.77  65.79  67.29  69.17  69.37  65.04  65.96  67.53  68.89
#> grainy  92.38  91.29  91.41  93.80  94.06  94.27  91.78  91.89  94.29  94.34
#> mealy   94.83  90.67  91.24  91.36  94.83  95.44  92.38  92.87  92.98  94.77
#> moist   84.08  82.80  82.90  82.93  85.65  85.67  85.12  85.26  85.29  86.55
#> chewi   86.50  84.60  84.72  86.16  86.49  87.50  86.05  86.22  87.61  87.62
#>           8,0    8,1    8,2    9,0    9,1   10,0
#> X       82.82  88.16  95.96  85.49  90.21  87.08
#> ref     90.82  94.67  94.93  91.52  94.42  91.79
#> hard    52.73  59.90  60.33  52.75  63.37  52.92
#> firm    71.26  80.42  80.49  71.81  80.88  71.82
#> elas    73.78  80.71  81.41  75.22  80.15  76.14
#> adhes   68.88  68.89  69.28  71.74  72.73  74.17
#> grainy  91.80  93.21  94.39  91.99  92.91  92.43
#> mealy   93.59  94.05  94.31  93.75  93.98  93.83
#> moist   86.40  86.60  87.34  87.11  88.40  87.14
#> chewi   87.11  88.40  88.43  87.27  89.53  87.28

# Scatter plot matrix with two first components from Chemical block
# and 1 component from the Compression block.
scoreplot(so, comps=list(1:2,1), ncomp=2, block=2)


# Result functions and more plots for SO-PLS 
# are found in ?sopls_results and ?sopls_plots.