- the pdf on my SlideShare repo,
- the Rmd on my Rpubs, and
- the raw text file from my Github.
17 March 2015
hydrogeological analysis using open source tools: case Cikapundung River
24 July 2014
Updated #R Code: GAM exercise using mgcv package
The previous GAM post was based on only one year dataset. I have added another four year dataset in to the system and unfortunately it needed several adjustment, especially for the knot (k) value.
So the following is the updated R code. I am sure someone can come up with more efficient code.
Cheers,
Erwin
Note:
We can use (x,y) coordinate as one of the predictor, as tensor function using "te()".
We can also include character-type column as the predictor.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 | #--- # title : MGCV package tryout # author: Dasapta Erwin Irawan^1 and Farzina Akter^2 # affiliation^1: Institut Teknologi Bandung (Indonesia) # affiliation^2: University of Sydney (Australia) # date : 22 July 2014 #--- # This code is following http://www3.nd.edu/~mclark19/learn/GAMS.pdf # Load library and data require("mgcv") data <- read.csv("alldata23.csv") ########################## ##### GAM ANALYSIS ####### ########################## # load library and data require("mgcv") data <- read.csv("alldata23.csv") group1 <- data[,c("x","y","ec","elv","aq","ph","hard","tds","temp","eh","Q")] group2 <- data[,c("x","y","ec","Ca","Mg","Fe","Mn","K","Na")] group3 = data[,c("x","y","ec","CO3","HCO3","CO2","Cl","SO4","NO2", "NO3","SiO2")] # GAM models (check, all predictors must be numeric) ################## FAMILY = GAUSSIAN ##################### ## ols (k=10 default changed to k=5, to avoid smoothing error) k1<-3 # change the knot (k) value to avoid this error message # ... basis dimension, k, increased to minimum possible ... # k=10 (default) gam11<-gam(ec ~ s(x,k=k1) + s(y,k=k1) + s(elv,k=k1) + s(ph,k=k1) + s(hard,k=k1) + s(tds,k=k1) + s(temp,k=k1) + s(eh,k=k1) + s(Q,k=k1), data=group1) # [dropping "Mg"] # I've tested each variables to avoid these error messages # ... max not meaningful for factors ... k2<-3 # (if you don't change it, then R will use previous k value) gam12<-gam(ec ~ s(x,k=k2) + s(y,k=k2) + s(Ca,k=k2) + s(Fe,k=k2) + s(K,k=k2) + s(Na,k=k2) + s(Mn,k=k2), data=group2) k3<-3 # (if you don't change it, then R will use previous k value) gam13<-gam(ec ~ s(x,k=k3) + s(y,k=k3) + s(CO3,k=k3) + s(HCO3,k=k3) + s(CO2,k=k3) + s(Cl,k=k3) + s(SO4,k=k3) + s(NO2,k=k3) + s(NO3,k=k3) + + s(SiO2,k=k3), data=group3) ## smoothing=thin plate smoothing #k1<-3 gam21<-gam(ec ~ s(x,k=k1,bs="tp") + s(y,k=k1,bs="tp") + s(elv,k=k1,bs="tp") + s(ph,k=k1,bs="tp") + s(hard,k=k1,bs="tp") + s(tds,k=k1,bs="tp") + s(temp,k=k1,bs="tp") + s(eh,k=k1,bs="tp") + s(Q,k=k1,bs="tp"), data=group1) #k2<-3 xxxxxxxxxxxx gam22<-gam(ec ~ s(x,k=k2,bs="tp") + s(y,k=k2,bs="tp") + s(Ca,k=k2,bs="tp") + s(Fe,k=k2,bs="tp") + s(Mn,k=k2,bs="tp") + s(K,k=k2,bs="tp") + s(Na,k=k2,bs="tp"), data=group2) #k3<-5 gam23<-gam(ec ~ s(x,k=k3,bs="tp") + s(y,k=k3,bs="tp") + s(CO3,k=k3,bs="tp") + s(HCO3,k=k3,bs="tp") + s(CO2,k=k3,bs="tp") + s(Cl,k=k3,bs="tp") + s(SO4,k=k3,bs="tp") + s(NO2,k=k3,bs="tp") + s(NO3,k=k3,bs="tp") + + s(SiO2,k=k3,bs="tp"), data=group3) ## smoothing=thin shrinkage #k1<-5 bsm<-"ts" gam31<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), data=group1) #k2<-3 xxxxxxxxxxxx bsm<-"ts" gam32<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), data=group2) #k3<-5 bsm<-"ts" gam33<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), data=group3) # smoothing=cubic regression spline #k1<-5 bsm<-"cr" gam41<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), data=group1) #k2<-3 xxxxxxxxxxxx gam42<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), data=group2) #k3<-5 gam43<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), data=group3) # smoothing=cubic shrinkage version bsm<-"cs" #k1<-5 gam51<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), data=group1) #k2<-3 xxxxxxxxxxxx gam52<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), data=group2) #k3<-5 gam53<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), data=group3) # smoothing=cyclic cubic regression spline k1<-5 [changed from 3 to 5] bsm<-"cc" gam61<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), data=group1) k2<-8 xxxxxxxxxxxxx gam62<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), data=group2) k3<-5 gam63<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), data=group3) # Dropping "cc" model, causing error, don't have cyclic pattern ################## FAMILY = GAMMA ##################### ## link=log, default smoothing #k1<-5 # k=10 (default) gam71<-gam(ec ~ s(x,k=k1) + s(y,k=k1) + s(elv,k=k1) + s(ph,k=k1) + s(hard,k=k1) + s(tds,k=k1) + s(temp,k=k1) + s(eh,k=k1) + s(Q,k=k1), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx gam72<-gam(ec ~ s(x,k=k2) + s(y,k=k2) + s(Ca,k=k2) + s(Fe,k=k2) + s(Mn,k=k2) + s(K,k=k2) + s(Na,k=k2), Gamma (link="log"), data=group2) #k3<-5 gam73<-gam(ec ~ s(x,k=k3) + s(y,k=k3) + s(CO3,k=k3) + s(HCO3,k=k3) + s(CO2,k=k3) + s(Cl,k=k3) + s(SO4,k=k3) + s(NO2,k=k3) + s(NO3,k=k3) + + s(SiO2,k=k3), Gamma (link="log"), data=group3) ## smoothing=thin plate smoothing #k1<-5 gam81<-gam(ec ~ s(x,k=k1,bs="tp") + s(y,k=k1,bs="tp") + s(elv,k=k1,bs="tp") + s(ph,k=k1,bs="tp") + s(hard,k=k1,bs="tp") + s(tds,k=k1,bs="tp") + s(temp,k=k1,bs="tp") + s(eh,k=k1,bs="tp") + s(Q,k=k1,bs="tp"), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx gam82<-gam(ec ~ s(x,k=k2,bs="tp") + s(y,k=k2,bs="tp") + s(Ca,k=k2,bs="tp") + s(Fe,k=k2,bs="tp") + s(Mn,k=k2,bs="tp") + s(K,k=k2,bs="tp") + s(Na,k=k2,bs="tp"), Gamma (link="log"), data=group2) #k3<-5 gam83<-gam(ec ~ s(x,k=k3,bs="tp") + s(y,k=k3,bs="tp") + s(CO3,k=k3,bs="tp") + s(HCO3,k=k3,bs="tp") + s(CO2,k=k3,bs="tp") + s(Cl,k=k3,bs="tp") + s(SO4,k=k3,bs="tp") + s(NO2,k=k3,bs="tp") + s(NO3,k=k3,bs="tp") + + s(SiO2,k=k3,bs="tp"), Gamma (link="log"), data=group3) ## smoothing=thin shrinkage #k1<-5 bsm<-"ts" gam91<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx bsm<-"ts" gam92<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), Gamma (link="log"), data=group2) #k3<-5 bsm<-"ts" gam93<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), Gamma (link="log"), data=group3) # Family=gaussian, smoothing=cubic regression spline #k1<-5 bsm<-"cr" gam101<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx gam102<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), Gamma (link="log"), data=group2) #k3<-5 gam103<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), Gamma (link="log"), data=group3) # smoothing=cubic shrinkage version bsm<-"cs" #k1<-5 gam111<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx gam112<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), Gamma (link="log"), data=group2) #k3<-5 gam113<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), Gamma (link="log"), data=group3) # smoothing=cyclic cubic regression spline # k1<-5 bsm<-"cc" gam121<-gam(ec ~ s(x,k=k1,bs=bsm) + s(y,k=k1,bs=bsm) + s(elv,k=k1,bs=bsm) + s(ph,k=k1,bs=bsm) + s(hard,k=k1,bs=bsm) + s(tds,k=k1,bs=bsm) + s(temp,k=k1,bs=bsm) + s(eh,k=k1,bs=bsm) + s(Q,k=k1,bs=bsm), Gamma (link="log"), data=group1) #k2<-3 xxxxxxxxxxxxx gam122<-gam(ec ~ s(x,k=k2,bs=bsm) + s(y,k=k2,bs=bsm) + s(Ca,k=k2,bs=bsm) + s(Fe,k=k2,bs=bsm) + s(Mn,k=k2,bs=bsm) + s(K,k=k2,bs=bsm) + s(Na,k=k2,bs=bsm), Gamma (link="log"), data=group2) #k3<-5 gam123<-gam(ec ~ s(x,k=k3,bs=bsm) + s(y,k=k3,bs=bsm) + s(CO3,k=k3,bs=bsm) + s(HCO3,k=k3,bs=bsm) + s(CO2,k=k3,bs=bsm) + s(Cl,k=k3,bs=bsm) + s(SO4,k=k3,bs=bsm) + s(NO2,k=k3,bs=bsm) + s(NO3,k=k3,bs=bsm) + + s(SiO2,k=k3,bs=bsm), Gamma (link="log"), data=group3) ######### GAM EVALUATION ################ # Gaussian AIC.gsdef<-AIC(gam11,gam12,gam13) AIC.gstp<-AIC(gam21,gam22,gam23) AIC.gsts<-AIC(gam31,gam32,gam33) AIC.gscr<-AIC(gam41,gam42,gam43) AIC.gscs<-AIC(gam51,gam52,gam53) AIC.gscc<-AIC(gam61,gam62,gam63) print(AIC.gsdef) ; print(AIC.gstp) # lowestAIC=gam13(3300.728) and gam23(3300.728) print(AIC.gsts) ; print(AIC.gscr) # lowestAIC=gam33(3296.121) and gam43(3295.407) print(AIC.gscs) ; print(AIC.gscc) # lowest AIC=gam53(3290.296) and gam63(3307.973) summary(gam13) # R-sq=0.359, GCV=24394, scale=22925, Dev=39.5% # signif pars=CO3, HCO3, CO2, Cl, NO2 gam.check(gam13) summary(gam23) # R-sq=0.359, GCV=24394, scale=22925, Dev=39.5% # sigpar=CO3, HCO3, CO2, Cl, NO2 gam.check(gam23) summary(gam33) # R-sq=0.358, GCV=23906, scale=22956, Dev=38.1% # sigpar=CO3, HCO3, CO2, Cl, NO2 gam.check(gam33) summary(gam43) # R-sq=0.372, GCV=23888, scale=22465, Dev=40.7% # sigpar=CO3, HCO3, CO2, Cl, NO2, SiO2 gam.check(gam43) summary(gam53) # R-sq=0.374, GCV=23369, scale=22403, Dev=39.7% # sigpar=CO3, HCO3, CO2, Cl, NO2 gam.check(gam53) # Gamma # using AIC AIC.gmdef<-AIC(gam71,gam72,gam73) AIC.gmtp<-AIC(gam81,gam82,gam83) AIC.gmts<-AIC(gam91,gam92,gam93) AIC.gmcr<-AIC(gam101,gam102,gam103) AIC.gmcs<-AIC(gam111,gam112,gam113) AIC.gmcc<-AIC(gam121,gam122,gam123) print(AIC.gmdef) ; print(AIC.gmtp) # lowestAIC=gam71(3137.232) and gam81(3137.232) print(AIC.gmts) ; print(AIC.gmcr) # lowestAIC=gam91(3133.663) and gam101(3138.866) print(AIC.gmcs) ; print(AIC.gmcc) # lowestAIC=gam111(3135.529) and gam121(3163.347) |
07 April 2014
[sci writing] literature review: the one with the search
Continuing my previous post, the following table is the result of reference searching on my hydrological case. I'll add more description later.
No | Keyword | Browser | Database | Iteration | Filter | Results | Book_eb | Book_ch | Book_rev | Conf | Thesis | Journal | Magazine | Newsletter | Newspaper | Other_ref | Oldest | Newest | |
1 | Cikapundung | Chrome | 1 | any | 43 | 15 | 0 | 0 | 0 | 0 | 9 | 0 | 0 | 19 | 0 | 1975 | 2013 | ||
2 | Cikapundung | Chrome | 2 | in title | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
3 | Cikapundung | Chrome | 3 | in title, online | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
4 | Citarum | Chrome | 1 | any | 1033 | 597 | 2 | 1 | 2 | 14 | 137 | 8 | 5 | 266 | 1 | 1502 | 2014 | ||
5 | Citarum | Chrome | 2 | in title | 70 | 5 | 5 | 0 | 9 | 5 | 25 | 0 | 0 | 21 | 0 | 1980 | 2014 | ||
6 | Citarum | Chrome | 3 | in title, online | 36 | 0 | 0 | 0 | 1 | 0 | 14 | 0 | 0 | 21 | 0 | 1993 | 2014 | ||
7 | Bandung | Chrome | 1 | any | 39639 | 8708 | 0 | 488 | 519 | 828 | 7403 | 0 | 0 | 21693 | 0 | 1693 | 2014 | ||
8 | Ciliwung | Chrome | 2 | in title | 53 | 1 | 0 | 0 | 2 | 1 | 3 | 1 | 0 | 45 | 0 | 1974 | 2014 | ||
9 | Ciliwung | Chrome | 3 | in title, online | 46 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 45 | 0 | 1996 | 2014 | ||
10 | Ciliwung | Chrome | 1 | any | 1024 | 138 | 3 | 0 | 0 | 8 | 69 | 5 | 0 | 801 | 0 | 1973 | 2014 | ||
11 | Bandung | Chrome | 2 | in title | 1391 | 111 | 0 | 45 | 68 | 35 | 364 | 0 | 0 | 768 | 0 | 1900 | 2014 | ||
12 | Bandung | Chrome | 3 | in title, online | 1111 | 15 | 0 | 43 | 0 | 0 | 259 | 11 | 19 | 764 | 0 | 1950 | 2014 | ||
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06 April 2014
[sci writing] literature review
Start to write about river water-groundwater relation
1. Introduction
All kinds of research, researcher must have a strong understanding of preceeding research on the same or similar subject. Master and PhD student, as a kind of researcher, must compose a literature review before they hold permit to start their research. Usually we use the term literature review as a form of formal written document that summarises all previous related researches.
Generally the steps are:
- searching articles with certain criteria.
- published article on reputable journals.
- presented abstract on reputable conferences.
- extract the results from each article, what data is used in it, and how the author analyse it.
- summarise and compile the result to mark a baseline for your research.
However if we dig deeper, we can find that there are at least two kinds of literature review:
- Annotated bibliography
- Systematic review
2. Annotated bibliography
What is an annotated bibliography? These are several good definitions on the term:
An annotated bibliography provides a brief account of the available research on a given topic. It is a list of research sources that includes concise descriptions and evaluations of each source.[UNSW] (https://student.unsw.edu.au/annotated-bibliography)
Another definition even gives an average sum of words:
An annotated bibliography is a list of citations to books, articles, and documents. Each citation is followed by a brief (usually about 150 words) descriptive and evaluative paragraph, the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited. [Cornell Univ] (http://guides.library.cornell.edu/annotatedbibliography).
another references to be added
According to the two references, it’s clear now that the steps previously mentioned in the introduction is for composing annotated bibliography.
Now we get to the real part. Searching for references. There’s so many ways to get related readings and references:
- The old-fashioned way is to go to your university library. Tempting huh :-) If I’d suggest this as the best way. Not only you’ll get the one document that you’ve been looking for, but also you’ll feel the atmosphere in there. Although there are more online documents nowadays, but still I’d sit still in the library (if I have time). You might by any chance get the oldest record on whatever you’re looking for.
Then there’s always be internet as the backbone of researcher around the globe. The problem is, where to find it.
- Google: the most obvious next man’s best friend. Off course there’re others, like: bing, and our old mate Yahoo. You might want to visit list of search engine. But be careful with using Google, because it crawls on any documents that matched with our keyword. So it could be a real scientific paper on a scientific journal, or a newsletter or simply an email in a miling list. But starting from November 2004, Google has make improvement on the matter by launching Google Scholar. Now you can get more refined result with this tools. Five years later, in December 2009, Microsoft launched Microsoft Academic.
- Citation database or scientific database: we’re already familiar with Scopus, Science direct, Proquest, or Web of Science. You can start with both links, since different company would likely have different database and searching algorithm. If you are working or affiliating to a university that has subscription to any of the database, then you have eliminated half of your problem :-).
- Or your university has a cross-referencing system that access multiple databases in the internet. You are the lucky one :-). Just type in the keyword in it then you get more results from multiple resources. I’ll continue later on with my own case of reference searching.
27 March 2014
[R] Hydromad Cikapundung (1)
@dasaptaerwin

