I will use the code from Module 4 Exercise to produce this R Markdown example

The file Temperature.csv contains temperature and salinity observations made at 31 locations along the Dutch coastline over 16 years. Sampling frequency was 0–4 times per month, depending on the season. Read in the file:

temp <- read.csv("Temperature.csv")
str(temp)
## 'data.frame':    8528 obs. of  16 variables:
##  $ Sample     : chr  "DANT.19900110" "DANT.19900206" "DANT.19900308" "DANT.19900404" ...
##  $ Date       : int  19900110 19900206 19900308 19900404 19900509 19900620 19900718 19900815 19900919 19901017 ...
##  $ DateNr     : chr  "10/1/90" "6/2/90" "8/3/90" "4/4/90" ...
##  $ dDay1      : int  7 34 64 91 126 168 196 224 259 287 ...
##  $ dDay2      : int  9 36 66 93 128 170 198 226 261 289 ...
##  $ dDay3      : int  9 36 66 93 128 170 198 226 261 289 ...
##  $ Station    : chr  "DANT" "DANT" "DANT" "DANT" ...
##  $ Area       : chr  "WZ" "WZ" "WZ" "WZ" ...
##  $ X31UE_ED50 : num  681380 681380 681380 681380 681380 ...
##  $ X31UN_ED50 : num  5920571 5920571 5920571 5920571 5920571 ...
##  $ Year       : int  1990 1990 1990 1990 1990 1990 1990 1990 1990 1990 ...
##  $ Month      : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ Season     : chr  "winter" "winter" "spring" "spring" ...
##  $ Salinity   : num  29.2 27.4 25 28.8 33.3 ...
##  $ Temperature: num  4 6 7.3 8.2 17.4 18.1 17 21 15.1 13.8 ...
##  $ CHLFa      : num  1.3 NA 21.1 25 10.2 6.2 7.9 7.85 13 11.8 ...
names(temp)
##  [1] "Sample"      "Date"        "DateNr"      "dDay1"       "dDay2"      
##  [6] "dDay3"       "Station"     "Area"        "X31UE_ED50"  "X31UN_ED50" 
## [11] "Year"        "Month"       "Season"      "Salinity"    "Temperature"
## [16] "CHLFa"

I first estimate the mean and standard deviation for temperature and salinity across all samples.

  • Mean
mean(temp$Temperature, na.rm = TRUE)
## [1] 12.20743
mean(temp$Salinity, na.rm = TRUE)
## [1] 29.70221
  • Standard Deviation
sd(temp$Temperature, na.rm = TRUE)
## [1] 5.412521
sd(temp$Salinity, na.rm = TRUE)
## [1] 5.421593

I then use tapply() estimate the average values of temperature and salinity across a) all sites and b) all years

  • By Stations (sites)
tapply(temp$Temperature, temp$Station, mean, na.rm = TRUE)
##     DANT     DREI       G6     GROO     HAMM     HANS     HUIB     LODS 
## 12.05908 12.77160 10.66570 12.25853 12.50000 13.54894 11.85353 12.61192 
##     MARS      N02      N10      N20      N70      R03      R50      R70 
## 12.39607 11.37433 12.45878 12.19753 12.14789 12.80000 13.94911 13.98022 
##     SOEL     T004     T010     T100     T135     T175     T235     VLIS 
## 13.21203 11.28425 12.37517 11.94766 11.75512 11.55431 11.32355 12.79292 
##      W02      W20      W70     WISS     ZIJP     ZUID 
## 10.51829 11.87937 12.18243 12.45090 12.55904 11.83928
tapply(temp$Salinity, temp$Station, mean, na.rm = TRUE)
##     DANT     DREI       G6     GROO     HAMM     HANS     HUIB     LODS 
## 28.94468 29.83813 30.59610 14.57571 31.35738 18.29124 29.52631 30.73000 
##     MARS      N02      N10      N20      N70      R03      R50      R70 
## 28.03457 28.78695 30.45223 31.93275 34.94147 30.54978 33.49888 33.67944 
##     SOEL     T004     T010     T100     T135     T175     T235     VLIS 
## 18.09477 32.08114 32.72095 34.56746 34.67667 34.75135 34.87812 29.55476 
##      W02      W20      W70     WISS     ZIJP     ZUID 
## 32.05992 33.31554 35.02006 31.75164 29.39230 28.83997
  • By Years
tapply(temp$Temperature, temp$Year, mean, na.rm = TRUE)
##     1990     1991     1992     1993     1994     1995     1996     1997 
## 11.99146 11.00885 11.55799 11.45385 12.07944 12.32080 10.72728 12.33687 
##     1998     1999     2000     2001     2002     2003     2004     2005 
## 12.13386 13.10577 12.61539 12.74162 13.05500 12.69017 12.56788 12.56112
tapply(temp$Salinity, temp$Year, mean, na.rm = TRUE)
##     1990     1991     1992     1993     1994     1995     1996     1997 
## 30.89873 30.88625 30.27116 29.52839 29.07707 28.94954 30.66670 30.54525 
##     1998     1999     2000     2001     2002     2003     2004     2005 
## 29.55748 29.03291 28.99534 28.22390 28.89323 29.60946 30.45629 30.35355

I then use aggregate() to estimate the average monthly values of temperature and salinity by year across all sites to make a time series

  • Temperature
aggregate(temp[,15], list(temp$Year, temp$Month), mean, na.rm = TRUE)
##     Group.1 Group.2         x
## 1      1990       1  6.313889
## 2      1991       1  5.210000
## 3      1992       1  5.858140
## 4      1993       1  4.965217
## 5      1994       1  5.691111
## 6      1995       1  5.778000
## 7      1996       1  3.645238
## 8      1997       1  2.146857
## 9      1998       1  6.685926
## 10     1999       1  5.717778
## 11     2000       1  5.622963
## 12     2001       1  4.754375
## 13     2002       1  4.427778
## 14     2003       1  4.848485
## 15     2004       1  5.558636
## 16     2005       1  5.877692
## 17     1990       2  6.475000
## 18     1991       2  3.576923
## 19     1992       2  5.040625
## 20     1993       2  5.231111
## 21     1994       2  4.814706
## 22     1995       2  6.400000
## 23     1996       2  1.751351
## 24     1997       2  2.793600
## 25     1998       2  5.023438
## 26     1999       2  4.280000
## 27     2000       2  5.635517
## 28     2001       2  5.717826
## 29     2002       2  7.634286
## 30     2003       2  3.864545
## 31     2004       2  5.739286
## 32     2005       2  4.670455
## 33     1990       3  8.192857
## 34     1991       3  5.286207
## 35     1992       3  6.525806
## 36     1993       3  5.521622
## 37     1994       3  5.815686
## 38     1995       3  6.800000
## 39     1996       3  2.950000
## 40     1997       3  6.747551
## 41     1998       3  6.965862
## 42     1999       3  6.684898
## 43     2000       3  6.984773
## 44     2001       3  5.268108
## 45     2002       3  7.487778
## 46     2003       3  6.042927
## 47     2004       3  5.784407
## 48     2005       3  5.051000
## 49     1990       4  9.153333
## 50     1991       4  8.365714
## 51     1992       4  8.030769
## 52     1993       4  8.584615
## 53     1994       4  7.742857
## 54     1995       4  8.386364
## 55     1996       4  6.392683
## 56     1997       4  8.507045
## 57     1998       4  8.965862
## 58     1999       4 10.036364
## 59     2000       4  8.857907
## 60     2001       4  8.117222
## 61     2002       4  9.589038
## 62     2003       4  9.197736
## 63     2004       4  9.695370
## 64     2005       4  9.044444
## 65     1990       5 14.357576
## 66     1991       5 10.185000
## 67     1992       5 12.074324
## 68     1993       5 13.170270
## 69     1994       5 11.987097
## 70     1995       5 11.572549
## 71     1996       5 10.101429
## 72     1997       5 12.223214
## 73     1998       5 13.181455
## 74     1999       5 13.028776
## 75     2000       5 13.255000
## 76     2001       5 12.031867
## 77     2002       5 12.416441
## 78     2003       5 13.620857
## 79     2004       5 12.478364
## 80     2005       5 11.883061
## 81     1990       6 16.277273
## 82     1991       6 13.059259
## 83     1992       6 16.887838
## 84     1993       6 16.024390
## 85     1994       6 14.637255
## 86     1995       6 14.632609
## 87     1996       6 14.996364
## 88     1997       6 15.570200
## 89     1998       6 16.557660
## 90     1999       6 16.019091
## 91     2000       6 15.611111
## 92     2001       6 15.330877
## 93     2002       6 16.343036
## 94     2003       6 18.874643
## 95     2004       6 15.784259
## 96     2005       6 15.061846
## 97     1990       7 17.423333
## 98     1991       7 17.724324
## 99     1992       7 18.745000
## 100    1993       7 17.142857
## 101    1994       7 19.314035
## 102    1995       7 18.335849
## 103    1996       7 16.509091
## 104    1997       7 18.483594
## 105    1998       7 17.108049
## 106    1999       7 18.442623
## 107    2000       7 16.645918
## 108    2001       7 19.071818
## 109    2002       7 17.872241
## 110    2003       7 19.644000
## 111    2004       7 17.292632
## 112    2005       7 18.799111
## 113    1990       8 18.976667
## 114    1991       8 19.550000
## 115    1992       8 18.905000
## 116    1993       8 17.376316
## 117    1994       8 19.903065
## 118    1995       8 20.385000
## 119    1996       8 18.390741
## 120    1997       8 20.919815
## 121    1998       8 18.749200
## 122    1999       8 19.174603
## 123    2000       8 18.756102
## 124    2001       8 19.292273
## 125    2002       8 20.403500
## 126    2003       8 21.038269
## 127    2004       8 19.780185
## 128    2005       8 17.692105
## 129    1990       9 16.831250
## 130    1991       9 17.896000
## 131    1992       9 15.958621
## 132    1993       9 15.660526
## 133    1994       9 15.753846
## 134    1995       9 17.243902
## 135    1996       9 15.953191
## 136    1997       9 17.910833
## 137    1998       9 15.998444
## 138    1999       9 18.999268
## 139    2000       9 17.424048
## 140    2001       9 15.645429
## 141    2002       9 18.297895
## 142    2003       9 17.982400
## 143    2004       9 16.174694
## 144    2005       9 17.883455
## 145    1990      10 13.851724
## 146    1991      10 13.647727
## 147    1992      10 13.095135
## 148    1993      10 13.648485
## 149    1994      10 12.884375
## 150    1995      10 15.133333
## 151    1996      10 13.725000
## 152    1997      10 13.920000
## 153    1998      10 11.752941
## 154    1999      10 13.080385
## 155    2000      10 13.697297
## 156    2001      10 14.866410
## 157    2002      10 13.262703
## 158    2003      10 12.246765
## 159    2004      10 12.790000
## 160    2005      10 14.498125
## 161    1990      11 10.345161
## 162    1991      11  8.400000
## 163    1992      11  8.900833
## 164    1993      11  8.580000
## 165    1994      11 11.212195
## 166    1995      11 11.479487
## 167    1996      11  9.386410
## 168    1997      11 10.031200
## 169    1998      11  9.037097
## 170    1999      11  7.207857
## 171    2000      11  9.189630
## 172    2001      11 10.069130
## 173    2002      11 10.565357
## 174    2003      11  9.401000
## 175    2004      11 10.301786
## 176    2005      11 11.562759
## 177    1990      12  6.766667
## 178    1991      12  6.556757
## 179    1992      12  7.576977
## 180    1993      12  5.532258
## 181    1994      12  9.012821
## 182    1995      12  5.417143
## 183    1996      12  6.581818
## 184    1997      12  6.399259
## 185    1998      12  6.080741
## 186    1999      12  5.637200
## 187    2000      12  7.550952
## 188    2001      12  7.821786
## 189    2002      12  5.246552
## 190    2003      12  6.464762
## 191    2004      12  7.444643
## 192    2005      12  7.111481
  • Salinity
aggregate(temp[,14], list(temp$Year, temp$Month), mean, na.rm = TRUE)
##     Group.1 Group.2        x
## 1      1990       1 30.27000
## 2      1991       1 29.77267
## 3      1992       1 29.99535
## 4      1993       1 28.19087
## 5      1994       1 27.31000
## 6      1995       1 27.97180
## 7      1996       1 30.66524
## 8      1997       1 31.24865
## 9      1998       1 30.24886
## 10     1999       1 28.94469
## 11     2000       1 28.49000
## 12     2001       1 29.25000
## 13     2002       1 28.19519
## 14     2003       1 28.65606
## 15     2004       1 28.64591
## 16     2005       1 30.72360
## 17     1990       2 27.94625
## 18     1991       2 30.51923
## 19     1992       2 30.47500
## 20     1993       2 27.25280
## 21     1994       2 28.97088
## 22     1995       2 25.15593
## 23     1996       2 30.01189
## 24     1997       2 28.73720
## 25     1998       2 30.55347
## 26     1999       2 26.74842
## 27     2000       2 28.62345
## 28     2001       2 26.99696
## 29     2002       2 26.19952
## 30     2003       2 26.75606
## 31     2004       2 25.41143
## 32     2005       2 29.20818
## 33     1990       3 30.22250
## 34     1991       3 30.27966
## 35     1992       3 30.16500
## 36     1993       3 28.32056
## 37     1994       3 27.95980
## 38     1995       3 28.45118
## 39     1996       3 30.35333
## 40     1997       3 30.33224
## 41     1998       3 26.51448
## 42     1999       3 27.82719
## 43     2000       3 26.74886
## 44     2001       3 27.01111
## 45     2002       3 27.08886
## 46     2003       3 27.52780
## 47     2004       3 29.26576
## 48     2005       3 29.38240
## 49     1990       4 30.80133
## 50     1991       4 30.84543
## 51     1992       4 29.69103
## 52     1993       4 29.49949
## 53     1994       4 27.25381
## 54     1995       4 28.28159
## 55     1996       4 29.99561
## 56     1997       4 29.89523
## 57     1998       4 30.20926
## 58     1999       4 26.46606
## 59     2000       4 27.78628
## 60     2001       4 25.79417
## 61     2002       4 29.27327
## 62     2003       4 29.42528
## 63     2004       4 30.29222
## 64     2005       4 29.66933
## 65     1990       5 30.71281
## 66     1991       5 29.63042
## 67     1992       5 29.55811
## 68     1993       5 30.34541
## 69     1994       5 29.02492
## 70     1995       5 29.05375
## 71     1996       5 30.96757
## 72     1997       5 29.87750
## 73     1998       5 30.07436
## 74     1999       5 28.90551
## 75     2000       5 29.11696
## 76     2001       5 27.69520
## 77     2002       5 28.68169
## 78     2003       5 27.61743
## 79     2004       5 30.51545
## 80     2005       5 29.39306
## 81     1990       6 31.01000
## 82     1991       6 31.08407
## 83     1992       6 30.35611
## 84     1993       6 30.54561
## 85     1994       6 28.83816
## 86     1995       6 28.32043
## 87     1996       6 30.93800
## 88     1997       6 30.86431
## 89     1998       6 29.16064
## 90     1999       6 29.79455
## 91     2000       6 29.80463
## 92     2001       6 28.86246
## 93     2002       6 29.54439
## 94     2003       6 27.59964
## 95     2004       6 30.69167
## 96     2005       6 30.86169
## 97     1990       7 31.43033
## 98     1991       7 30.83892
## 99     1992       7 30.59800
## 100    1993       7 30.94595
## 101    1994       7 30.38172
## 102    1995       7 29.41472
## 103    1996       7 31.25352
## 104    1997       7 30.05484
## 105    1998       7 29.86098
## 106    1999       7 30.31197
## 107    2000       7 29.52940
## 108    2001       7 29.14891
## 109    2002       7 30.07845
## 110    2003       7 31.02720
## 111    2004       7 31.00930
## 112    2005       7 30.15822
## 113    1990       8 31.99467
## 114    1991       8 31.43059
## 115    1992       8 30.80000
## 116    1993       8 30.53184
## 117    1994       8 30.16051
## 118    1995       8 29.85034
## 119    1996       8 31.21519
## 120    1997       8 30.58132
## 121    1998       8 30.79800
## 122    1999       8 30.69317
## 123    2000       8 29.97169
## 124    2001       8 30.04818
## 125    2002       8 29.98167
## 126    2003       8 31.83269
## 127    2004       8 31.41574
## 128    2005       8 30.64439
## 129    1990       9 30.41125
## 130    1991       9 31.36160
## 131    1992       9 31.25241
## 132    1993       9 28.51892
## 133    1994       9 30.61487
## 134    1995       9 29.36300
## 135    1996       9 30.43723
## 136    1997       9 30.03083
## 137    1998       9 30.19549
## 138    1999       9 30.03122
## 139    2000       9 29.35476
## 140    2001       9 27.70486
## 141    2002       9 29.12079
## 142    2003       9 31.38060
## 143    2004       9 31.03040
## 144    2005       9 31.44145
## 145    1990      10 31.91690
## 146    1991      10 31.58044
## 147    1992      10 31.80270
## 148    1993      10 30.09182
## 149    1994      10 30.50844
## 150    1995      10 30.29039
## 151    1996      10 31.50750
## 152    1997      10 31.62538
## 153    1998      10 26.48765
## 154    1999      10 29.21885
## 155    2000      10 29.77703
## 156    2001      10 28.18974
## 157    2002      10 27.88711
## 158    2003      10 30.37000
## 159    2004      10 31.61171
## 160    2005      10 30.68656
## 161    1990      11 31.53484
## 162    1991      11 31.11848
## 163    1992      11 28.24167
## 164    1993      11 29.79150
## 165    1994      11 28.81049
## 166    1995      11 30.25692
## 167    1996      11 30.36205
## 168    1997      11 31.85209
## 169    1998      11 27.67930
## 170    1999      11 28.35071
## 171    2000      11 29.72741
## 172    2001      11 27.49217
## 173    2002      11 28.56679
## 174    2003      11 31.03300
## 175    2004      11 31.16250
## 176    2005      11 31.25586
## 177    1990      12 31.10160
## 178    1991      12 31.42028
## 179    1992      12 29.92356
## 180    1993      12 28.58935
## 181    1994      12 28.97487
## 182    1995      12 29.41657
## 183    1996      12 29.53676
## 184    1997      12 31.20455
## 185    1998      12 29.48020
## 186    1999      12 28.57640
## 187    2000      12 27.88381
## 188    2001      12 28.03893
## 189    2002      12 29.41345
## 190    2003      12 29.75091
## 191    2004      12 30.50429
## 192    2005      12 30.53444

I then use the table() function to determine the number of observations:

  • At each station
table(temp$Station)
## 
## DANT DREI   G6 GROO HAMM HANS HUIB LODS MARS  N02  N10  N20  N70  R03  R50  R70 
##  300  293  278  296  295  309  296  294  296  402  665  266  268  161  106  106 
## SOEL T004 T010 T100 T135 T175 T235 VLIS  W02  W20  W70 WISS ZIJP ZUID 
##  295  339  261  258  259  258  258  421  272  191  190  296  296  303
  • For each year
table(temp$Year)
## 
## 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 
##  367  392  438  436  590  590  583  636  608  570  563  568  545  550  540  552
  • At each station per year
table(temp$Station, temp$Year)
##       
##        1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
##   DANT   12   12   18   19   17   13   19   20   22   21   22   21   21   21
##   DREI   13   13   13   13   19   21   20   20   21   20   20   20   20   20
##   G6     12   16   20   17   21   24   23   28   23   21   13   12   12   12
##   GROO   12   12   18   19   17   12   18   19   21   21   21   21   21   21
##   HAMM   13   13   13   13   20   21   20   21   20   20   21   20   20   20
##   HANS   13   16   13   13   21   24   19   19   18   18   29   29   20   19
##   HUIB   12   11   18   19   17   12   19   19   21   21   21   22   21   21
##   LODS   13   13   13   13   20   21   20   21   20   20   20   20   20   20
##   MARS   12   12   18   18   16   12   19   19   22   21   21   21   21   21
##   N02    12   17   20   17   27   29   31   40   37   29   24   27   23   23
##   N10    47   45   40   46   53   56   43   52   45   43   36   37   30   31
##   N20    12   12   11   11   18   18   18   18   18   18   19   19   19   19
##   N70    12   11   11   11   18   18   18   18   18   19   18   20   20   19
##   R03     0    5    7    7   13   17   17   23   20    9    8    7    7    7
##   R50     0    5    7    7   10    7    7    7    7    7    7    7    7    7
##   R70     0    5    7    7   10    7    7    7    7    7    7    7    7    7
##   SOEL   13   13   13   12   20   22   20   21   20   20   20   20   20   20
##   T004   12   14   20   16   26   27   27   33   28   20   19   19   19   20
##   T010   12   10   11   10   18   18   18   18   18   18   18   18   18   19
##   T100   12   10   10   10   18   18   18   18   18   18   18   18   18   18
##   T135   12   10   10   10   18   18   18   18   18   18   17   19   18   19
##   T175   12   10   10   10   18   18   18   18   18   18   18   18   18   18
##   T235   12   10   10   10   18   18   18   18   18   18   18   18   18   18
##   VLIS   14   18   21   24   35   36   22   23   22   22   30   31   30   32
##   W02    12   17   20   17   21   23   23   28   23   16   12   12   12   12
##   W20    12   12   11   11   12   12   12   12   12   13   12   12   12   12
##   W70    12   12   11   11   12   12   12   12   12   12   12   12   12   12
##   WISS   13   13   13   13   20   21   20   22   20   20   21   20   20   20
##   ZIJP   13   13   13   13   20   21   20   23   20   20   20   20   20   20
##   ZUID   11   12   18   19   17   14   19   21   21   22   21   21   21   22
##       
##        2004 2005
##   DANT   21   21
##   DREI   20   20
##   G6     12   12
##   GROO   21   22
##   HAMM   20   20
##   HANS   19   19
##   HUIB   21   21
##   LODS   20   20
##   MARS   21   22
##   N02    22   24
##   N10    29   32
##   N20    17   19
##   N70    18   19
##   R03     7    7
##   R50     7    7
##   R70     7    7
##   SOEL   20   21
##   T004   19   20
##   T010   18   19
##   T100   18   18
##   T135   18   18
##   T175   18   18
##   T235   18   18
##   VLIS   31   30
##   W02    12   12
##   W20    12   12
##   W70    12   12
##   WISS   20   20
##   ZIJP   20   20
##   ZUID   22   22

That’s it for Module 6 Exercise