Kasus 1*

library("neuralnet")
## Warning: package 'neuralnet' was built under R version 3.1.3
## Loading required package: grid
## Loading required package: MASS
traininginput <-  as.data.frame(runif(50, min=0, max=100))
trainingoutput <- sqrt(traininginput)
trainingdata <- cbind(traininginput,trainingoutput)
colnames(trainingdata) <- c("Input","Output")
net.sqrt <- neuralnet(Output~Input,trainingdata, hidden=10, threshold=0.01)
print(net.sqrt)
## Call: neuralnet(formula = Output ~ Input, data = trainingdata, hidden = 10,     threshold = 0.01)
## 
## 1 repetition was calculated.
## 
##             Error Reached Threshold Steps
## 1 0.0005643073494    0.009592216057 16505
 #Test the neural network on some training data
testdata <- as.data.frame((1:10)^2) #Generate some squared numbers
net.results <- compute(net.sqrt, testdata)
 #Run them through the neural network
 
#Lets see what properties net.sqrt has
ls(net.results)
## [1] "net.result" "neurons"
#Lets see the results
print(net.results$net.result)
##              [,1]
##  [1,] 1.082991001
##  [2,] 2.000640820
##  [3,] 3.020899704
##  [4,] 3.993782547
##  [5,] 5.002344138
##  [6,] 6.004458234
##  [7,] 6.996583306
##  [8,] 7.998473499
##  [9,] 9.007460416
## [10,] 9.986290718
#Lets display a better version of the results
cleanoutput <- cbind(testdata,sqrt(testdata),
                         as.data.frame(net.results$net.result))
colnames(cleanoutput) <- c("Input","Expected Output","Neural Net Output")
print(cleanoutput)
##    Input Expected Output Neural Net Output
## 1      1               1       1.082991001
## 2      4               2       2.000640820
## 3      9               3       3.020899704
## 4     16               4       3.993782547
## 5     25               5       5.002344138
## 6     36               6       6.004458234
## 7     49               7       6.996583306
## 8     64               8       7.998473499
## 9     81               9       9.007460416
## 10   100              10       9.986290718

Kasus 2*

library(neuralnet)
itrain <- iris[sample(1:150, 50),]
itrain$setosa <- c(itrain$Species == "setosa")
itrain$versicolor <- c(itrain$Species == "versicolor")
itrain$virginica <- c(itrain$Species == "virginica")
itrain$Species <- NULL
inet <- neuralnet(setosa + versicolor + virginica ~ Sepal.Length + Sepal.Width + Petal.Length + Petal.Width, itrain, hidden=3, lifesign="full")
## hidden: 3    thresh: 0.01    rep: 1/1    steps:    1000  min thresh: 0.137180245
##                                                    2000  min thresh: 0.09378143248
##                                                    3000  min thresh: 0.07155774292
##                                                    4000  min thresh: 0.07155774292
##                                                    5000  min thresh: 0.07155774292
##                                                    6000  min thresh: 0.07155774292
##                                                    7000  min thresh: 0.07155774292
##                                                    8000  min thresh: 0.07155774292
##                                                    9000  min thresh: 0.07155774292
##                                                   10000  min thresh: 0.07155774292
##                                                   11000  min thresh: 0.06004895105
##                                                   12000  min thresh: 0.02990162162
##                                                   13000  min thresh: 0.02512168527
##                                                   14000  min thresh: 0.0245153536
##                                                   15000  min thresh: 0.0245153536
##                                                   16000  min thresh: 0.0245153536
##                                                   17000  min thresh: 0.0245153536
##                                                   18000  min thresh: 0.0245153536
##                                                   19000  min thresh: 0.02360921011
##                                                   20000  min thresh: 0.02360921011
##                                                   21000  min thresh: 0.02360921011
##                                                   22000  min thresh: 0.02360921011
##                                                   23000  min thresh: 0.02360921011
##                                                   24000  min thresh: 0.02360921011
##                                                   25000  min thresh: 0.02360921011
##                                                   26000  min thresh: 0.02360921011
##                                                   27000  min thresh: 0.02325615007
##                                                   28000  min thresh: 0.02325615007
##                                                   29000  min thresh: 0.02325615007
##                                                   30000  min thresh: 0.0228829469
##                                                   31000  min thresh: 0.02233009868
##                                                   32000  min thresh: 0.0214910105
##                                                   33000  min thresh: 0.0214910105
##                                                   34000  min thresh: 0.02132753096
##                                                   35000  min thresh: 0.01950619595
##                                                   36000  min thresh: 0.01950619595
##                                                   37000  min thresh: 0.01947938595
##                                                   38000  min thresh: 0.01797372178
##                                                   39000  min thresh: 0.01797372178
##                                                   40000  min thresh: 0.01769753965
##                                                   41000  min thresh: 0.01769753965
##                                                   42000  min thresh: 0.01700626385
##                                                   43000  min thresh: 0.01700626385
##                                                   44000  min thresh: 0.01672159629
##                                                   45000  min thresh: 0.01672159629
##                                                   46000  min thresh: 0.01580463948
##                                                   47000  min thresh: 0.01536023906
##                                                   48000  min thresh: 0.01536023906
##                                                   49000  min thresh: 0.01472203243
##                                                   50000  min thresh: 0.01472203243
##                                                   51000  min thresh: 0.01457902381
##                                                   52000  min thresh: 0.01440348188
##                                                   53000  min thresh: 0.01411069359
##                                                   54000  min thresh: 0.01354772715
##                                                   55000  min thresh: 0.01323812633
##                                                   56000  min thresh: 0.0131189376
##                                                   57000  min thresh: 0.01285350763
##                                                   58000  min thresh: 0.01261026478
##                                                   59000  min thresh: 0.01238672266
##                                                   60000  min thresh: 0.01190481066
##                                                   61000  min thresh: 0.01190481066
##                                                   62000  min thresh: 0.01160194701
##                                                   63000  min thresh: 0.01134952055
##                                                   64000  min thresh: 0.01116540247
##                                                   65000  min thresh: 0.01083546289
##                                                   66000  min thresh: 0.01083546289
##                                                   67000  min thresh: 0.01073533767
##                                                   68000  min thresh: 0.01047215478
##                                                   69000  min thresh: 0.01001640238
##                                                   70000  min thresh: 0.01000323813
##                                                   71000  min thresh: 0.01000323813
##                                                   71073  error: 0.05167  time: 15.51 secs
predict <- compute(inet, iris[1:4])
result<-0
for (i in 1:150) { result[i] <- which.max(predict$net.result[i,]) }
for (i in 1:150) { if (result[i]==1) {result[i] = "setosa"} }
for (i in 1:150) { if (result[i]==2) {result[i] = "versicolor"} }
for (i in 1:150) { if (result[i]==3) {result[i] = "virginica"} }
comparison <- iris
comparison$Predicted <- result