Running examples in ‘RWsearch-Ex.R’ failed
The error most likely occurred in:

> ### Name: archivedb
> ### Title: CRAN archive (CRAN-archive.html + archivedb)
> ### Aliases: archivedb archivedb_down archivedb_load archivedb_npkgs
> ###   archivedb_pkgs archivedb_rempkgs archivedb_list
> 
> ### ** Examples
> 
> ### DOWNLOAD archivedb AND COMPARE IT WITH crandb.
> ## In real life, download archivedb and crandb from CRAN
> ## with the functions archivedb_down() and crandb_down().  
> ## In this example, we load two small files.
> 
> crandb_load(system.file("data", "zcrandb.rda", package = "RWsearch"))
$newfile
[1] "crandb loaded. 110 packages listed between 2011-04-13 and 2020-04-17"

> archivedb_load(system.file("aabb", "zCRAN-archive.html", package = "RWsearch")) 
archivedb loaded in .GlobalEnv. 99 listed.
> archivedb_npkgs()
   pcrandb parchivedb     pfirst   pupdated   premoved 
       110         99         18         92          7 
> archivedb_pkgs()
 [1] "BTSPAS"         "Brobdingnag"    "CHNOSZ"         "CSTools"       
 [5] "CalibratR"      "ChainLadder"    "CompLognormal"  "Delaporte"     
 [9] "EpiEstim"       "FBFsearch"      "FatTailsR"      "IAPWS95"       
[13] "ICcalib"        "KernSmooth"     "MALDIquant"     "MASS"          
[17] "Matrix"         "PredictionR"    "RWsearch"       "RcppHMM"       
[21] "RcppHNSW"       "RobExtremes"    "RxnSim"         "SCI"           
[25] "Seurat"         "Signac"         "VetResearchLMM" "XML"           
[29] "abind"          "actuar"         "aiRthermo"      "autoencoder"   
[33] "automl"         "boot"           "brew"           "bsearchtools"  
[37] "canprot"        "cascsim"        "class"          "cluster"       
[41] "codetools"      "compHclust"     "elasticsearchr" "episensr"      
[45] "findR"          "fitdistrplus"   "fitur"          "foreign"       
[49] "grid"           "h2o"            "htmltools"      "htmlwidgets"   
[53] "igraph"         "jsonlite"       "kerasR"         "latexpdf"      
[57] "lattice"        "lbiassurv"      "magrittr"       "mbbefd"        
[61] "mgcv"           "multicross"     "myTAI"          "networkD3"     
[65] "nlme"           "nnet"           "packagefinder"  "pacman"        
[69] "pdfsearch"      "qmap"           "rSQM"           "randomsearch"  
[73] "robmixglm"      "rpart"          "scMappR"        "searchConsoleR"
[77] "searchable"     "searcher"       "sig"            "simPop"        
[81] "sos"            "spatial"        "splines"        "ssdtools"      
[85] "stratifyR"      "survival"       "tcltk"          "teachingApps"  
[89] "tensorflow"     "tfestimators"   "uptasticsearch" "visNetwork"    
[93] "websearchr"     "zFactor"        "zicounts"       "zmatrix"       
[97] "zonator"        "zoo"            "zstdr"         
> archivedb_rempkgs()
[1] "grid"     "splines"  "tcltk"    "zicounts" "zmatrix"  "zonator"  "zstdr"   
> 
> lst <- archivedb_list()
> lapply(lst, head)
$pkgs_crandb
[1] "abind"                "actuar"               "aiRthermo"           
[4] "AmmoniaConcentration" "AnnuityRIR"           "AquaEnv"             

$pkgs_archivedb
[1] "BTSPAS"      "Brobdingnag" "CHNOSZ"      "CSTools"     "CalibratR"  
[6] "ChainLadder"

$pkgs_first
[1] "AmmoniaConcentration" "AnnuityRIR"           "AquaEnv"             
[4] "bioPN"                "CompDist"             "CRANsearcher"        

$pkgs_updated
[1] "abind"       "actuar"      "aiRthermo"   "autoencoder" "automl"     
[6] "boot"       

$pkgs_removed
[1] "grid"     "splines"  "tcltk"    "zicounts" "zmatrix"  "zonator" 

$dfr_crandb
               Package  Published
1                abind 2016-07-21
2               actuar 2019-12-04
3            aiRthermo 2018-09-16
4 AmmoniaConcentration 2016-12-05
5           AnnuityRIR 2017-11-03
6              AquaEnv 2016-09-06

$dfr_archivedb
      Package   Archived
1      BTSPAS 2019-12-04
2 Brobdingnag 2018-08-13
3      CHNOSZ 2020-03-16
4     CSTools 2020-01-16
5   CalibratR 2019-08-19
6 ChainLadder 2020-02-10

$dfr_first
                Package  Published
4  AmmoniaConcentration 2016-12-05
5            AnnuityRIR 2017-11-03
6               AquaEnv 2016-09-06
9                 bioPN 2014-03-04
23             CompDist 2017-08-17
26         CRANsearcher 2017-06-26

$dfr_updated
       Package  Published
1        abind 2016-07-21
2       actuar 2019-12-04
3    aiRthermo 2018-09-16
7  autoencoder 2015-07-02
8       automl 2020-01-16
10        boot 2019-12-20

$dfr_removed
    Package   Archived
49     grid 2008-02-16
83  splines 2008-02-16
87    tcltk 2008-02-16
95 zicounts 2008-04-23
96  zmatrix 2008-02-16
97  zonator 2019-03-15

$npkgs
   pcrandb parchivedb     pfirst   pupdated   premoved 
       110         99         18         92          7 

> lapply(lst, tail)
$pkgs_crandb
[1] "vsgoftest"  "websearchr" "wfindr"     "XML"        "zFactor"   
[6] "zoo"       

$pkgs_archivedb
[1] "zFactor"  "zicounts" "zmatrix"  "zonator"  "zoo"      "zstdr"   

$pkgs_first
[1] "spectralAnalysis" "STI"              "titrationCurves"  "univariateML"    
[5] "vsgoftest"        "wfindr"          

$pkgs_updated
[1] "VetResearchLMM" "visNetwork"     "websearchr"     "XML"           
[5] "zFactor"        "zoo"           

$pkgs_removed
[1] "splines"  "tcltk"    "zicounts" "zmatrix"  "zonator"  "zstdr"   

$dfr_crandb
       Package  Published
105  vsgoftest 2018-06-24
106 websearchr 2018-10-23
107     wfindr 2016-07-03
108        XML 2020-01-20
109    zFactor 2019-08-01
110        zoo 2020-01-10

$dfr_archivedb
    Package   Archived
94  zFactor 2019-03-01
95 zicounts 2008-04-23
96  zmatrix 2008-02-16
97  zonator 2019-03-15
98      zoo 2020-01-10
99    zstdr 2019-01-11

$dfr_first
             Package  Published
92  spectralAnalysis 2018-06-12
94               STI 2015-08-19
100  titrationCurves 2016-02-11
101     univariateML 2019-12-18
105        vsgoftest 2018-06-24
107           wfindr 2016-07-03

$dfr_updated
           Package  Published
103 VetResearchLMM 2018-04-22
104     visNetwork 2019-12-06
106     websearchr 2018-10-23
108            XML 2020-01-20
109        zFactor 2019-08-01
110            zoo 2020-01-10

$dfr_removed
    Package   Archived
83  splines 2008-02-16
87    tcltk 2008-02-16
95 zicounts 2008-04-23
96  zmatrix 2008-02-16
97  zonator 2019-03-15
99    zstdr 2019-01-11

$npkgs
   pcrandb parchivedb     pfirst   pupdated   premoved 
       110         99         18         92          7 

> xlim <- as.Date(range(lst$dfr_archivedb$Archived)) ; xlim
[1] "2008-02-16" "2020-04-17"
> op <- par(mfrow = c(2,1))
> hist(as.Date(lst$dfr_first$Published), 
+      breaks = 12, freq = TRUE, las = 1, xlim = xlim)
Error in as.Date.numeric(e) : 'origin' must be supplied
Calls: hist ... unlist -> lapply -> FUN -> as.Date -> as.Date.numeric
Execution halted