library(neuralnet)

## Error in library(neuralnet): there is no package called 'neuralnet'

concrete<-read.csv(file = "concrete.txt",stringsAsFactors = F)#get the data

## Warning in file(file, "rt"): cannot open file 'concrete.txt': No such file or
## directory

## Error in file(file, "rt"): cannot open the connection

normalize<-function(x){
  return((x-min(x))/(max(x)-min(x)))
}
concrete<-as.data.frame(lapply(concrete, normalize))

## Error in lapply(concrete, normalize): object 'concrete' not found

concrete_train<-concrete[1:773,]

## Error in eval(expr, envir, enclos): object 'concrete' not found

concrete_test<-concrete[774:1030,]

## Error in eval(expr, envir, enclos): object 'concrete' not found

concrete_model<-neuralnet(strength~cement+slag+ash+water+superplastic+coarseagg+fineagg+age,data = concrete_train,hidden = 5)

## Error in neuralnet(strength ~ cement + slag + ash + water + superplastic + : could not find function "neuralnet"

model_res<-compute(concrete_model,concrete_test[,1:8])

## Error in compute(concrete_model, concrete_test[, 1:8]): could not find function "compute"

x=model_res$net.result

## Error in eval(expr, envir, enclos): object 'model_res' not found

y=concrete_test$strength

## Error in eval(expr, envir, enclos): object 'concrete_test' not found

cor(x,y)

## Error in is.data.frame(y): object 'y' not found

plot(concrete_model)

## Error in plot(concrete_model): object 'concrete_model' not found