# MacroPCA examples

## Raymaekers, J. and Rousseeuw, P.J.

### 2026-02-25

# Introduction

This file contains some examples of the functions related to the MacroPCA routine. More specifically, `MacroPCA`, `MacroPCApredict` and `cellMap` will be illustrated.

    library("cellWise")
    library("gridExtra") # has grid.arrange()

# Small generated example

We will first look at a small artificial example.

    set.seed(12345) # for reproducibility
    n <- 50; d <- 10
    A <- matrix(0.9, d, d); diag(A) = 1
    round(A,1) # true covariance matrix

    ##       [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
    ##  [1,]  1.0  0.9  0.9  0.9  0.9  0.9  0.9  0.9  0.9   0.9
    ##  [2,]  0.9  1.0  0.9  0.9  0.9  0.9  0.9  0.9  0.9   0.9
    ##  [3,]  0.9  0.9  1.0  0.9  0.9  0.9  0.9  0.9  0.9   0.9
    ##  [4,]  0.9  0.9  0.9  1.0  0.9  0.9  0.9  0.9  0.9   0.9
    ##  [5,]  0.9  0.9  0.9  0.9  1.0  0.9  0.9  0.9  0.9   0.9
    ##  [6,]  0.9  0.9  0.9  0.9  0.9  1.0  0.9  0.9  0.9   0.9
    ##  [7,]  0.9  0.9  0.9  0.9  0.9  0.9  1.0  0.9  0.9   0.9
    ##  [8,]  0.9  0.9  0.9  0.9  0.9  0.9  0.9  1.0  0.9   0.9
    ##  [9,]  0.9  0.9  0.9  0.9  0.9  0.9  0.9  0.9  1.0   0.9
    ## [10,]  0.9  0.9  0.9  0.9  0.9  0.9  0.9  0.9  0.9   1.0

    library(MASS) # only needed for the following line:
    x <- mvrnorm(n, rep(0,d), A)
    x[sample(1:(n * d), 50, FALSE)] <- NA
    x[sample(1:(n * d), 25, FALSE)] <- 10
    x[sample(1:(n * d), 25, FALSE)] <- -10
    x <- cbind(1:n, x)
    # When not specifying MacroPCApars all defaults are used:
    MacroPCA.out <- MacroPCA(x, k = 0)

    ##
    ##  The input data has 50 rows and 11 columns.
    ##
    ##  The data contained 1 columns that were identical to the case number
    ##  (number of the row).
    ##  Their column names are:
    ##
    ## [1] X1
    ##
    ##  These columns will be ignored in the analysis.
    ##  We continue with the remaining 10 columns:
    ##
    ##  [1] X2  X3  X4  X5  X6  X7  X8  X9  X10 X11
    ##
    ##  The final data set we will analyze has 50 rows and 10 columns.
    ##
    ##
    ## Initial eigenvalues:
    ##  5.244268 0.098185 0.08510009 0.05672098 0.05008563 0.04632771 0.03971856 0.03232433 0.01782431 0.01617235

plot of chunk unnamed-chunk-3

    ##
    ## The cumulative percentage of explained variability
    ## by the first 10 components is:
    ##   PC1   PC2   PC3   PC4   PC5   PC6   PC7   PC8   PC9  PC10
    ##  92.2  93.9  95.4  96.4  97.3  98.1  98.8  99.4  99.7 100.0
    ##
    ## Based on explained variability >= 80% one would select k = 1.
    ##
    ## Please use this information and the scree plot to select a value of k
    ## and rerun MacroPCA with it.

    MacroPCA.out <- MacroPCA(x, k = 1)

    ##
    ##  The input data has 50 rows and 11 columns.
    ##
    ##  The data contained 1 columns that were identical to the case number
    ##  (number of the row).
    ##  Their column names are:
    ##
    ## [1] X1
    ##
    ##  These columns will be ignored in the analysis.
    ##  We continue with the remaining 10 columns:
    ##
    ##  [1] X2  X3  X4  X5  X6  X7  X8  X9  X10 X11
    ##
    ##  The final data set we will analyze has 50 rows and 10 columns.
    ##
    ##
    ## Initial eigenvalues:
    ##  5.210214 0.1121324 0.08729449 0.0532014 0.04884532 0.04532176 0.03756785 0.03267324 0.0154171 0.01106728
    ##
    ## XciSVD$rank, Xcih.SVD$rank, k and kmax:  10 10 1 10
    ##
    ## Performed an extra reweighting step because k = 1 < rank = 10 .
    ##
    ## The final step used eigenvectors of MCD scatter.

    cellMap(MacroPCA.out$stdResid)

plot of chunk unnamed-chunk-4

    # Red cells have higher value than predicted, blue cells lower,
    # white cells are missing values, and all other cells are yellow.

# TopGear dataset

The Top Gear data contains information on 297 cars.

    library(robustHD)
    data(TopGear)
    dim(TopGear)

    myTopGear = TopGear
    rownames(myTopGear) = paste(myTopGear[,1],myTopGear[,2])
    # These rownames are make and model of the cars.
    rownames(myTopGear)[165] = "Mercedes-Benz G" # name was too long
    myTopGear = myTopGear[,-31] # removes subjective variable `Verdict'

    # Transform some skewed variables:
    transTG = myTopGear
    transTG$Price = log(myTopGear$Price)
    transTG$Displacement = log(myTopGear$Displacement)
    transTG$BHP = log(myTopGear$BHP)
    transTG$Torque = log(myTopGear$Torque)
    transTG$TopSpeed = log(myTopGear$TopSpeed)

    # Check the data:
    checkData = checkDataSet(transTG, silent = TRUE)

    ##
    ##  The final data set we will analyze has 296 rows and 11 columns.
    ##

    # With option silent = FALSE we obtain more information:
    #
    # The input data has 297 rows and 31 columns.
    #
    # The input data contained 19 non-numeric columns (variables).
    # Their column names are:
    #
    #  [1] Maker         Model              Type               Fuel
    #  [5] DriveWheel    AdaptiveHeadlights AdjustableSteering AlarmSystem
    #  [9] Automatic     Bluetooth          ClimateControl     CruiseControl
    # [13] ElectricSeats Leather            ParkingSensors     PowerSteering
    # [17] SatNav        ESP                Origin
    #
    # These columns will be ignored in the analysis.
    # We continue with the remaining 12 numeric columns:
    #
    # [1] Price Cylinders Displacement BHP   Torque Acceleration TopSpeed
    # [8] MPG   Weight    Length       Width Height
    #
    # The data contained 1 rows with over 50% of NAs.
    # Their row names are:
    #
    #   [1] Citroen C5 Tourer
    #
    # These rows will be ignored in the analysis.
    # We continue with the remaining 296 rows:
    #
    #   [1] Alfa Romeo Giulietta             Alfa Romeo MiTo
    # .......
    # [295] Volvo XC70                       Volvo XC90
    #
    # The data contained 1 columns with zero or tiny median absolute deviation.
    # Their column names are:
    #
    # [1] Cylinders
    #
    # These columns will be ignored in the analysis.
    # We continue with the remaining 11 columns:
    #
    # [1] Price  Displacement BHP   Torque Acceleration TopSpeed MPG
    # [8] Weight Length       Width Height
    #
    # The final data set we will analyze has 296 rows and 11 columns.

    # The remainder of the dataset:
    remTG = checkData$remX
    dim(remTG)

    ## [1] 296  11

    colSums(is.na(remTG)) # we still have quite a few NA's, especially in Weight:

    ##        Price Displacement          BHP       Torque Acceleration     TopSpeed
    ##            0            8            3            3            0            3
    ##          MPG       Weight       Length        Width       Height
    ##           11           32           10           15           10

    # Check robust scale of the variables:
    locscale = estLocScale(remTG)
    round(locscale$scale,2)

    ##        Price Displacement          BHP       Torque Acceleration     TopSpeed
    ##         0.60         0.38         0.59         0.60         3.51         0.17
    ##          MPG       Weight       Length        Width       Height
    ##        17.08       381.02       420.89        91.95       131.82

    # The scales are clearly different, so we will standardize before PCA.
    # This is the argument scale=TRUE in MacroPCApars below.

    # Small option lists (MacroPCA will automatically extend them with the
    # default choices for the other options):
    DDCpars <- list(fastDDC = FALSE, silent = TRUE)
    MacroPCApars <- list(DDCpars = DDCpars, scale = TRUE, silent = TRUE)
    # Note that MacroPCA needs DDCpars because it first runs DDC.

    # To choose the number k of principal components we can run MacroPCA with k=0:
    MacroPCAtransTG0 <- MacroPCA(transTG,k=0,MacroPCApars=MacroPCApars)

    ##
    ##  The final data set we will analyze has 296 rows and 11 columns.
    ##

plot of chunk unnamed-chunk-6

    ##
    ## The cumulative percentage of explained variability
    ## by the first 10 components is:
    ##  PC1  PC2  PC3  PC4  PC5  PC6  PC7  PC8  PC9 PC10
    ## 70.3 83.4 90.4 93.3 95.3 96.7 97.8 98.7 99.3 99.7
    ##
    ## Based on explained variability >= 80% one would select k = 2.
    ##
    ## Please use this information and the scree plot to select a value of k
    ## and rerun MacroPCA with it.

    MacroPCAtransTG <- MacroPCA(transTG,k=2,MacroPCApars=MacroPCApars) # takes about 1 second.

    ##
    ##  The final data set we will analyze has 296 rows and 11 columns.
    ##

    names(MacroPCAtransTG)

    ##  [1] "MacroPCApars" "remX"         "DDC"          "scaleX"       "k"
    ##  [6] "loadings"     "eigenvalues"  "center"       "alpha"        "h"
    ## [11] "It"           "diff"         "X.NAimp"      "scores"       "OD"
    ## [16] "cutoffOD"     "SD"           "cutoffSD"     "highOD"       "highSD"
    ## [21] "residScale"   "stdResid"     "indcells"     "NAimp"        "Cellimp"
    ## [26] "Fullimp"

    MacroPCAtransTG$MacroPCApars # these are all the options used, starting with DDCpars:

    ## $DDCpars
    ## $DDCpars$fracNA
    ## [1] 0.5
    ##
    ## $DDCpars$numDiscrete
    ## [1] 3
    ##
    ## $DDCpars$precScale
    ## [1] 1e-12
    ##
    ## $DDCpars$cleanNAfirst
    ## [1] "automatic"
    ##
    ## $DDCpars$tolProb
    ## [1] 0.99
    ##
    ## $DDCpars$corrlim
    ## [1] 0.5
    ##
    ## $DDCpars$combinRule
    ## [1] "wmean"
    ##
    ## $DDCpars$returnBigXimp
    ## [1] FALSE
    ##
    ## $DDCpars$silent
    ## [1] TRUE
    ##
    ## $DDCpars$nLocScale
    ## [1] 25000
    ##
    ## $DDCpars$fastDDC
    ## [1] FALSE
    ##
    ## $DDCpars$standType
    ## [1] "1stepM"
    ##
    ## $DDCpars$corrType
    ## [1] "gkwls"
    ##
    ## $DDCpars$transFun
    ## [1] "wrap"
    ##
    ## $DDCpars$nbngbrs
    ## [1] 100
    ##
    ##
    ## $kmax
    ## [1] 10
    ##
    ## $alpha
    ## [1] 0.5
    ##
    ## $scale
    ## [1] TRUE
    ##
    ## $maxdir
    ## [1] 250
    ##
    ## $distprob
    ## [1] 0.99
    ##
    ## $silent
    ## [1] TRUE
    ##
    ## $maxiter
    ## [1] 20
    ##
    ## $tol
    ## [1] 0.005
    ##
    ## $bigOutput
    ## [1] TRUE

    MacroPCAtransTG$cutoffOD # cutoff value for orthogonal distances OD:

    ## [1] 1.737869

    MacroPCAtransTG$cutoffSD # cutoff value for score distances OD:

    ## [1] 3.034854

    length(MacroPCAtransTG$indcells) # list of flagged cells

    ## [1] 126

## Also run ICPCA (iterative classical PCA):

    ICPCAtransTG <- ICPCA(remTG,k=2,scale=TRUE,tolProb=0.99)
    names(ICPCAtransTG)

    ##  [1] "scaleX"      "k"           "loadings"    "eigenvalues" "center"
    ##  [6] "covmatrix"   "It"          "diff"        "X.NAimp"     "scores"
    ## [11] "OD"          "cutoffOD"    "SD"          "cutoffSD"    "highOD"
    ## [16] "highSD"      "residScale"  "stdResid"    "indcells"

    # Compare imputed values for missings:
    MacroPCAtransTG$X.NAimp[c(94,176),8]

    ##  Ford Kuga Mini Coupe
    ##   1654.907   1125.878

    ICPCAtransTG$X.NAimp[c(94,176),8]

    ##  Ford Kuga Mini Coupe
    ##   1774.286   1001.698

    # CAR MAGAZINE: Ford Kuga Kuga 2.0 TDCi weighs 1605kg
    # CAR MAGAZINE: MINI Coupe 1.6T Cooper  weighs 1165kg

    # Make untransformed submatrix of X for labeling the cells
    # in the residual plot:
    tempTG = myTopGear[checkData$rowInAnalysis,checkData$colInAnalysis]
    dim(tempTG)

    ## [1] 296  11

    tempTG$Price = tempTG$Price/1000 # to avoid printing long numbers

    showrows = c(12,42,50,51,52,59,72,94,98,135,150,164,176,
                 180,195,196,198,209,210,215,219,234,259,277) # these 24 cars will be shown

    # Make the ggplot2 objects for the residual maps by the function cellMap:
    ggpICPCA = cellMap(ICPCAtransTG$stdResid, showcellvalues="D",
                       D=tempTG, mTitle="ICPCA residual map",
                       showrows=showrows, sizecellvalues = 0.7)

    plot(ggpICPCA)

plot of chunk unnamed-chunk-8

    ggpMacroPCA = cellMap(MacroPCAtransTG$stdResid, showcellvalues="D",
                          D=tempTG, mTitle="MacroPCA residual map",
                           showrows=showrows, sizecellvalues = 0.7)
    plot(ggpMacroPCA)

plot of chunk unnamed-chunk-8

    # Creating the combined pdf:
    # pdf(file="TopGear_IPCA_MacroPCA_residualMap.pdf", width=12, height=10)
    # gridExtra::grid.arrange(ggpICPCA, ggpMacroPCA, ncol=2) # arranges two plots on a page
    # dev.copy(pdf, file="TopGear_IPCA_MacroPCA_residualMap.pdf", width=20, height=16)
    # dev.off()

    ### Creating the outlier maps

    outlierMap(MacroPCAtransTG,title="MacroPCA outlier map",
               labelOut=FALSE)
    rowlabels = rownames(tempTG)
    plotLabs = rep("",nrow(tempTG))
    plotLabs[42]  = rowlabels[42] # BMW i3
    plotLabs[50]  = "Bugatti"
    plotLabs[52]  = rowlabels[52] # Caterham Super 7
    plotLabs[59]  = rowlabels[59] # Chevrolet Volt
    plotLabs[180] = rowlabels[180] # Mitsubishi i-MiEV
    plotLabs[195] = rowlabels[195] # Noble M600
    plotLabs[196] = rowlabels[196] # Pagani Huayra
    plotLabs[219] = rowlabels[219] # Renault Twizy
    plotLabs[234] = rowlabels[234] # Ssangyong Rodius
    plotLabs[259] = rowlabels[259] # Vauxhall Ampera
    textPos = cbind(MacroPCAtransTG$SD,MacroPCAtransTG$OD)
    textPos[42,1]  = textPos[42,1] -0.5 # BMW i3
    textPos[42,2]  = textPos[42,2] +0.8 # BMW i3
    textPos[50,1]  = textPos[50,1] -0.03 # Bugatti Veyron
    textPos[50,2]  = textPos[50,2] +0.05 # Bugatti Veyron
    textPos[52,1]  = textPos[52,1] +0.3  # Caterham Super 7
    textPos[52,2]  = textPos[52,2] -0.5  # Caterham Super 7
    textPos[59,1]  = textPos[59,1] -0.05 # Chevrolet Volt
    textPos[59,2]  = textPos[59,2] -0.1  # Chevrolet Volt
    textPos[180,1] = textPos[180,1] -1.2 # Mitsubishi i-MiEV
    textPos[180,2] = textPos[180,2] +0.6 # Mitsubishi i-MiEV
    textPos[195,1] = textPos[195,1] -0.05 # Noble M600
    textPos[195,2] = textPos[195,2] +0.35 # Noble M600
    textPos[196,1] = textPos[196,1] -0.6 # Pagani Huayra
    textPos[196,2] = textPos[196,2] +0.7 # Pagani Huayra
    textPos[219,1] = textPos[219,1] -0.03 # Renault Twizy
    textPos[234,1] = textPos[234,1] +0.1 # Ssangyong Rodius
    textPos[234,2] = textPos[234,2] +0.6 # Ssangyong Rodius
    textPos[259,1] = textPos[259,1] -1.35 # Vauxhall Ampera
    textPos[259,2] = textPos[259,2] +0.65 # Vauxhall Ampera
    text(textPos,plotLabs,cex=0.8,pos=4)

plot of chunk unnamed-chunk-9

    # dev.copy(pdf,"TopGear_MacroPCA_outlierMap.pdf",width=6,height=6)
    # dev.off()

    outlierMap(ICPCAtransTG,title="ICPCA outlier map",labelOut=FALSE)
    plotLabs = rep("",nrow(tempTG))
    plotLabs[42]  = rowlabels[42]  # BMW i3
    plotLabs[50]  = rowlabels[50]  # Bugatti Veyron
    plotLabs[52]  = rowlabels[52]  # Caterham Super 7
    plotLabs[59]  = rowlabels[59]  # Chevrolet Volt
    plotLabs[180] = rowlabels[180] # Mitsubishi i-MiEV
    plotLabs[195] = rowlabels[195] # Noble M600
    plotLabs[196] = rowlabels[196] # Pagani Huayra
    plotLabs[219] = rowlabels[219] # Renault Twizy
    plotLabs[234] = rowlabels[234] # Ssangyong Rodius
    plotLabs[259] = rowlabels[259] # Vauxhall Ampera
    textPos = cbind(ICPCAtransTG$SD,ICPCAtransTG$OD)
    textPos[50,1]  = textPos[50,1] -0.05 # Bugatti Veyron
    textPos[50,2]  = textPos[50,2] +0.05 # Bugatti Veyron
    textPos[52,1]  = textPos[52,1] -0.07 # Caterham Super 7
    textPos[52,2]  = textPos[52,2] -0.37 # Caterham Super 7
    textPos[59,1]  = textPos[59,1] -0.05 # Chevrolet Volt
    textPos[59,2]  = textPos[59,2] -0.3  # Chevrolet Volt
    textPos[180,1] = textPos[180,1] -1.2 # Mitsubishi i-MiEV
    textPos[180,2] = textPos[180,2] +0.23 # Mitsubishi i-MiEV
    textPos[195,1] = textPos[195,1] +0.25 # Noble M600
    textPos[195,2] = textPos[195,2] +0.2 # Noble M600
    textPos[196,1] = textPos[196,1] -0.05 # Pagani Huayra
    textPos[196,2] = textPos[196,2] +0.32 # Pagani Huayra
    textPos[219,1] = textPos[219,1] -0.8 # Renault Twizy
    textPos[219,2] = textPos[219,2] +0.4 # Renault Twizy
    textPos[234,1] = textPos[234,1] -0.05 # Ssangyong Rodius
    textPos[234,2] = textPos[234,2] +0.2 # Ssangyong Rodius
    textPos[259,1] = textPos[259,1] -0.9 # Vauxhall Ampera
    textPos[259,2] = textPos[259,2] +0.4 # Vauxhall Ampera
    text(textPos,plotLabs, cex=0.8, pos=4)

plot of chunk unnamed-chunk-9

    # dev.copy(pdf,"TopGear_ICPCA_outlierMap.pdf",width=6,height=6)
    # dev.off()

# TopGear dataset: prediction of new data

    # For comparison, remake the residual map of the entire dataset, but now
    # showing the values of the residuals instead of the data values:

    ggpMacroPCAres = cellMap(MacroPCAtransTG$stdResid,
                             showcellvalues="R", sizecellvalues = 0.7,
                             mTitle="MacroPCA residual map",
                             showrows=showrows)
    plot(ggpMacroPCAres)

plot of chunk unnamed-chunk-10

    # Define the "initial" dataset as the rows not in these 24:
    initX = remTG[-showrows,]
    dim(initX)

    ## [1] 272  11

    # Fit initX:
    MacroPCAinitX = MacroPCA(initX,k=2,MacroPCApars=MacroPCApars)

    ##
    ##  The final data set we will analyze has 271 rows and 11 columns.
    ##

    # Define the "new" data to predict:
    newX = remTG[showrows,]
    dim(newX)

    ## [1] 24 11

    # Make predictions by MacroPCApredict.
    # Its inputs are:
    #
    # Xnew            : the new data (test data), which must be a
    #                   matrix or a data frame.
    #                   It must always be provided.
    # InitialMacroPCA : the output of the MacroPCA function on the
    #                   initial (training) dataset. Must be provided.
    # MacroPCApars    : the input options to be used for the prediction.
    #                   By default the options of InitialMacroPCA
    #                   are used. For the complete list of options
    #                   see the function MacroPCA.

    predictMacroPCA = MacroPCApredict(newX,MacroPCAinitX)
    # We did not need to specify the third argument because it is taken
    # from the initial fit MacroPCAinitX .

    names(predictMacroPCA)

    ##  [1] "MacroPCApars" "DDC"          "scaleX"       "k"            "loadings"
    ##  [6] "eigenvalues"  "center"       "It"           "diff"         "Xnew.NAimp"
    ## [11] "scores"       "OD"           "cutoffOD"     "SD"           "cutoffSD"
    ## [16] "highOD"       "highSD"       "residScale"   "stdResid"     "indcells"
    ## [21] "NAimp"        "Cellimp"      "Fullimp"

    # The outputs are similar to those of of MacroPCA.

    # Make the residual map:
    ggpMacroPCApredict = cellMap(predictMacroPCA$stdResid,
                                 showcellvalues="R", sizecellvalues = 0.7,
                                 mTitle="MacroPCApredict residual map")
    plot(ggpMacroPCApredict) # is very similar to that based on all the data!

plot of chunk unnamed-chunk-10

    # Creating the combined pdf:
    # pdf(file="TopGear_MacroPCApredict_residualMap.pdf",width=12,height=10)
    # gridExtra::grid.arrange(ggpMacroPCAres,ggpMacroPCApredict,ncol=2)
    # dev.off()

# Glass dataset

The glass data consists of spectra with 750 wavelengths of 180 archaeological glass samples.

    data(data_glass)

    library(rrcov) # for robust PCA:

    dim(data_glass)

    ## [1] 180 750

    # Do not scale the spectra in the glass data:
    MacroPCApars$scale = FALSE

    # Check data
    checkData = checkDataSet(data_glass, silent=TRUE)

    ##
    ##  The final data set we will analyze has 180 rows and 737 columns.
    ##

    # With checkData = checkDataSet(glass, silent=FALSE) we obtain more information:
    #
    #  The input data has 180 rows and 750 columns.
    #
    #  The data contained 11 discrete columns with 3 or fewer values.
    #  Their column names are:
    #
    #  [1] V1  V2  V3  V4  V5  V6  V7  V8  V9  V10 V11
    #
    #  These columns will be ignored in the analysis.
    #  We continue with the remaining 739 columns:
    #
    #   [1] V12  V13  V14  V15  V16  V17  V18  V19  V20  V21  V22  V23  V24  V25
    #    ......
    # [729] V740 V741 V742 V743 V744 V745 V746 V747 V748 V749 V750
    #
    #  The data contained 2 columns with zero or tiny median absolute deviation.
    #  Their column names are:
    #
    # [1] V12 V13
    #
    #  These columns will be ignored in the analysis.
    #  We continue with the remaining 737 columns:
    #
    #   [1] V14  V15  V16  V17  V18  V19  V20  V21  V22  V23  V24  V25  V26  V27
    #    ......
    # [729] V742 V743 V744 V745 V746 V747 V748 V749 V750
    #
    #  The final data set we will analyze has 180 rows and 737 columns.

    remglass = checkData$remX
    n <- nrow(remglass); n

    ## [1] 180

    d = ncol(remglass); d # the first 13 variables had scale 0:

    ## [1] 737

    # Compare ICPCA and MacroPCA:

    ICPCAglass <- ICPCA(remglass,k=4,scale=F,tolProb=0.99)

    MacroPCAglass = MacroPCA(remglass,k=4,MacroPCApars=MacroPCApars) # takes 8 seconds

    nrowsinblock = 5
    rowlabels = rep("",floor(n/nrowsinblock));
    rowlabels[1] = "1"
    rowlabels[floor(n/nrowsinblock)] = "n";

    ncolumnsinblock = 5
    columnlabels = rep("",floor(d/ncolumnsinblock));
    columnlabels[1] = "1";
    columnlabels[floor(d/ncolumnsinblock)] = "d"

    ggpICPCA <- cellMap(ICPCAglass$stdResid,
                        rowblocklabels=rowlabels,
                        columnblocklabels=columnlabels,
                        mTitle="ICPCA residual map",
                        rowtitle="glass samples",
                        columntitle="wavelengths",
                        nrowsinblock=5,
                        ncolumnsinblock=5)

    ggpMacroPCA <- cellMap(MacroPCAglass$stdResid,
                           rowblocklabels=rowlabels,
                           columnblocklabels=columnlabels,
                           mTitle="MacroPCA residual map",
                           rowtitle="glass samples",
                           columntitle="wavelengths",
                           nrowsinblock=5,
                           ncolumnsinblock=5)

    grid.arrange(ggpMacroPCA,ggpICPCA,nrow=2)

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    # pdfName = "Glass_MacroPCA_ICPCA_residualMap.pdf"
    # dev.copy(pdf, pdfName, width=12, height=8)
    # dev.off()

## We now compare MacroPCA with ROBPCA:

    library(rrcov) # only needed for PcaHubert()
    ROBPCAglass = PcaHubert(remglass,k=4,alpha=0.5)
    # Calculate ROBPCA residuals and standardize them:
    Xhat = sweep(ROBPCAglass@scores %*% t(ROBPCAglass@loadings),
                 2,ROBPCAglass@center,"+")
    Xresid = remglass - Xhat
    scaleRes = estLocScale(Xresid,type="1stepM",center=F)$scale
    stdResidROBPCA = sweep(Xresid,2,scaleRes,"/")

    ggpROBPCA <- cellMap(stdResidROBPCA,
                         rowblocklabels=rowlabels,
                         columnblocklabels=columnlabels,
                         mTitle="ROBPCA residual map",
                         rowtitle="glass samples",
                         columntitle="wavelengths",
                         nrowsinblock=5,
                         ncolumnsinblock=5)

    grid.arrange(ggpMacroPCA, ggpROBPCA, nrow=2)

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    # pdfName = "Glass_MacroPCA_ROBPCA_residualMap.pdf"
    # dev.copy(pdf, pdfName, width=12, height=8)
    # dev.off()

## We now compare fastDDC=FALSE with fastDDC=TRUE in MacroPCA:

    fastDDCpars = list(fastDDC=TRUE, silent=TRUE)
    fastMacroPCApars = list(DDCpars=fastDDCpars, scale=FALSE, silent=TRUE)

    fastMacroPCAglass = MacroPCA(data_glass,k=4,MacroPCApars=fastMacroPCApars) # 2 seconds

    ##
    ##  The final data set we will analyze has 180 rows and 737 columns.
    ##

    ggpfastMacroPCA <- cellMap(fastMacroPCAglass$stdResid,
                               columnblocklabels=columnlabels,
                               rowblocklabels=rowlabels,
                               mTitle="MacroPCA with fastDDC=T",
                               columntitle="wavelengths",
                               rowtitle="glass samples",
                               ncolumnsinblock=5,
                               nrowsinblock=5)

    grid.arrange(ggpMacroPCA, ggpfastMacroPCA, nrow=2) # The results are similar:

plot of chunk unnamed-chunk-15

    # pdfName = "Glass_MacroPCA_residualMaps.pdf"
    # dev.copy(pdf, pdfName, width=12, height=8)
    # dev.off()

# DPOSS dataset

Finally we analyze the DPOSS data. This is a random subset of 20’000 stars from the Digitized Palomar Sky Survey described by Odewahn et al (1998).

    data(data_dposs)

    colnames(data_dposs); dim(data_dposs)

    ##  [1] "MAperF" "MTotF"  "MCoreF" "AreaF"  "IR2F"   "csfF"   "EllipF" "MAperJ"
    ##  [9] "MTotJ"  "MCoreJ" "AreaJ"  "IR2J"   "csfJ"   "EllipJ" "MAperN" "MTotN"
    ## [17] "MCoreN" "AreaN"  "IR2N"   "csfN"   "EllipN"

    ## [1] 20000    21

    n = nrow(data_dposs); n

    ## [1] 20000

    # Count missing cells
    missmat = is.na(data_dposs)
    sizemat = nrow(missmat)*ncol(missmat); sizemat

    ## [1] 420000

    100*sum(as.vector(missmat))/sizemat # 50.2% of the values are missing:

    ## [1] 50.20952

    # Count rows with missings
    missrow = length(which(rowSums(missmat) > 0))
    100*missrow/nrow(missmat) # 84.6% of the rows contain missing values:

    ## [1] 84.61

    # PERFORM ICPCA AND MACROPCA

    ICPCAdposs = ICPCA(data_dposs,k=4,scale=TRUE)
    names(ICPCAdposs)

    ##  [1] "scaleX"      "k"           "loadings"    "eigenvalues" "center"
    ##  [6] "covmatrix"   "It"          "diff"        "X.NAimp"     "scores"
    ## [11] "OD"          "cutoffOD"    "SD"          "cutoffSD"    "highOD"
    ## [16] "highSD"      "residScale"  "stdResid"    "indcells"

    # MacroPCA options with fracNA allowing for many NA's:
    DDCPars = list(fastDDC=F,fracNA=1.0)
    MacroPCAPars = list(DDCpars=DDCPars,scale=TRUE,silent=T)
    MacroPCAdposs = MacroPCA(data_dposs,k=4,MacroPCApars=MacroPCAPars) # takes 6 seconds

    ## SCREE PLOTS

    barplot(ICPCAdposs$eigenvalues,
            main="ICPCA scree plot", ylab="eigenvalues",
            names.arg=1:length(ICPCAdposs$eigenvalues))

plot of chunk unnamed-chunk-17

    # dev.copy(pdf,"DPOSS_ICPCA_screeplot.pdf",width=6,height=6)
    # dev.off()

    barplot(MacroPCAdposs$eigenvalues,
            main="MacroPCA scree plot", ylab="eigenvalues",
            names.arg=1:length(MacroPCAdposs$eigenvalues))

plot of chunk unnamed-chunk-17

    # Not as concentrated in the first eigenvalue.
    # dev.copy(pdf,"DPOSS_MacroPCA_screeplot.pdf",width=6,height=6)
    # dev.off()

    ## LOADINGS
    ICPCAdposs$loadings[,2] = -ICPCAdposs$loadings[,2]

    matplot(ICPCAdposs$loadings[,1:2],main="ICPCA loadings",
            xlab="variables",ylab="Loadings",col=c("black","blue"),
            ylim=c(-0.4,0.6),type="l",lty=c(1,2),lwd=2)
    abline(v=7.5,col="red")
    abline(v=14.5,col="red")

plot of chunk unnamed-chunk-18

    # dev.copy(pdf,"DPOSS_ICPCA_loadings.pdf",width=5,height=5)
    # dev.off()

    matplot(MacroPCAdposs$loadings[,1:2],main="MacroPCA loadings",
            xlab="variables",ylab="Loadings",col=c("black","blue"),
            ylim=c(-0.3,0.5),type="l",lty=c(1,2),lwd=2)
    abline(v=7.5,col="red")
    abline(v=14.5,col="red")

plot of chunk unnamed-chunk-18

    # dev.copy(pdf,"DPOSS_MacroPCA_loadings.pdf",width=5,height=5)
    # dev.off()

    # Select the 150 rows with highest OD from MacroPCA
    dpossOD = MacroPCAdposs$OD
    summary(dpossOD)

    ##      Min.   1st Qu.    Median      Mean   3rd Qu.      Max.
    ##   0.04344   0.45833   0.99144   2.01535   2.31592 145.53136

    n = length(dpossOD); n

    ## [1] 20000

    sortOD = order(dpossOD,1:n)
    summary(sortOD); sortOD[1:5]

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##       1    5001   10000   10000   15000   20000

    ## [1] 10370  6891  1320 17270  7993

    indHighOD = sortOD[n-150+1:n]
    indHighOD = na.omit(indHighOD)
    summary(indHighOD); length(indHighOD)

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##     157    5009    8222    9549   15101   19979

    ## [1] 150

    indLowOD = sortOD[1:(n-150)]
    indLowOD = na.omit(indLowOD)
    summary(indLowOD); length(indLowOD)

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##       1    5001   10014   10004   15000   20000

    ## [1] 19850

    ## OUTLIER MAPS

    dpossColList = list(class1=list(col="black",index=indLowOD),
                        class2=list(col="red",index=indHighOD))

    outlierMap(ICPCAdposs,title="ICPCA outlier map",
               col=dpossColList,labelOut=FALSE)

plot of chunk unnamed-chunk-19

    # dev.copy(pdf,"DPOSS_ICPCA_outlierMap.pdf",width=8,height=8)
    # dev.off()

    outlierMap(MacroPCAdposs,title="MacroPCA outlier map",
               col=dpossColList,labelOut=FALSE)

plot of chunk unnamed-chunk-19

    # dev.copy(pdf,"DPOSS_MacroPCA_outlierMap.pdf",width=8,height=8)
    # dev.off()

    ## ICPCA SCORE PLOTS
    ICPCAdposs$scores[,2] = -ICPCAdposs$scores[,2]

    plot(ICPCAdposs$scores[,1:2],main="ICPCA scores",xlab="PC1",ylab="PC2")
    points(ICPCAdposs$scores[indHighOD,1:2],pch=16,col="red")

plot of chunk unnamed-chunk-20

    # dev.copy(pdf,"DPOSS_ICPCA_Scores12.pdf",width=5,height=5)
    # dev.off()

    plot(ICPCAdposs$scores[,c(1,3)],main="ICPCA scores",xlab="PC1",ylab="PC3")
    points(ICPCAdposs$scores[indHighOD,c(1,3)],pch=16,col="red")

plot of chunk unnamed-chunk-20

    plot(ICPCAdposs$scores[,2:3],main="ICPCA scores",xlab="PC2",ylab="PC3")
    points(ICPCAdposs$scores[indHighOD,2:3],pch=16,col="red")

plot of chunk unnamed-chunk-20

    # MacroPCA SCORE PLOTS
    MacroPCAdposs$scores[,2] = -MacroPCAdposs$scores[,2]
    MacroPCAdposs$scores[,3] = -MacroPCAdposs$scores[,3]

    plot(MacroPCAdposs$scores[,1:2],main="MacroPCA scores",xlab="PC1",ylab="PC2")
    points(MacroPCAdposs$scores[indHighOD,1:2],pch=16,col="red")

plot of chunk unnamed-chunk-20

    # dev.copy(pdf,"DPOSS_MacroPCA_Scores12.pdf",width=5,height=5)
    # dev.off()

    plot(MacroPCAdposs$scores[,c(1,3)],main="MacroPCA scores",xlab="PC1",ylab="PC3")
    points(MacroPCAdposs$scores[indHighOD,c(1,3)],pch=16,col="red")

plot of chunk unnamed-chunk-20

    plot(MacroPCAdposs$scores[,2:3],main="MacroPCA scores",xlab="PC2",ylab="PC3")
    points(MacroPCAdposs$scores[indHighOD,2:3],pch=16,col="red")

plot of chunk unnamed-chunk-20

    # RESIDUAL MAPS

    dpossH = na.omit(indHighOD)
    summary(dpossH); length(as.vector(dpossH))

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##     157    5009    8222    9549   15101   19979

    ## [1] 150

    dpossL = na.omit(indLowOD)
    summary(dpossL); length(as.vector(dpossL))

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##       1    5001   10014   10004   15000   20000

    ## [1] 19850

    set.seed(0)
    dpossH = sample(dpossH,150)
    dpossL = sample(dpossL,300)
    showrowsdposs = c(dpossH,dpossL)
    summary(showrowsdposs)

    ##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
    ##     150    5110    9818   10115   15554   19991

    length(showrowsdposs)

    ## [1] 450

    rowlabels = c("OS1","OS2","OS3","OS4","OS5","OS6",
                  "S1","S2","S3","S4","S5","S6","S7","S8",
                  "S9","S10","S11","S12")

    ggpICPCAdposs = cellMap(ICPCAdposs$stdResid,
                            rowblocklabels=rowlabels,
                            mTitle="ICPCA residual map",
                            rowtitle="",
                            showrows=showrowsdposs,
                            nrowsinblock=25,
                            ncolumnsinblock=1,
                            sizetitles=1.5)
    plot(ggpICPCAdposs) # not much to see:

plot of chunk unnamed-chunk-21

    # dev.copy(pdf,"DPOSS_ICPCA_residualMap.pdf",width=8,height=6)
    # dev.off()

    ggpMacroPCAdposs = cellMap(MacroPCAdposs$stdResid,
                               rowblocklabels=rowlabels,
                               mTitle="MacroPCA residual map",
                               rowtitle="",
                               showrows=showrowsdposs,
                               nrowsinblock=25,
                               ncolumnsinblock=1,
                               sizetitles=1.5)
    plot(ggpMacroPCAdposs) # interesting structure:

plot of chunk unnamed-chunk-21

    # dev.copy(pdf,"DPOSS_MacroPCA_residualMap.pdf",width=8,height=6)
    # dev.off()