Dear all;
I have run a neural network to predict a variable according to 3
independent variables. I used "neuralnet" package and the codes were:
"> met = read.csv("./met.csv",header = TRUE, sep = ",")
> attach(met)
> head(met)
> met2 = met
> str(met2)
'data.frame': 211362 obs. of 4 variables:
$ t : num 14.9 13.9 16.3 16 13.4 ...
$ rrr24: num NA NA NA NA NA NA NA NA NA NA ...
$ sshn : num NA NA NA NA NA NA NA NA NA NA ...
$ u : num 56.9 67.5 87.1 88.6 82 ...> met2 = na.omit(met2)
> dim(met2)
[1] 130765 4
> set.seed(7896129)
> test_met <- read.csv("./test_met.csv",header = TRUE, sep =
",")
> attach(test_met)
> head(test_met)
> test_met = na.omit(test_met)
> dim(test_met)
[1] 73778 4
> n2 <- neuralnet(u ~ t + rrr24 + sshn,
data = met2,
hidden = 4,
err.fct = "sse",
linear.output = TRUE,
lifesign = 'full',
rep = 1,
algorithm = "rprop+",
stepmax = 100000,
threshold = 0.01
)
hidden: 4 thresh: 0.01 rep: 1/1 steps: 138 error:
30691876.99866 time: 6.35 secs
> n2$result.matrix
[,1]
error 3.069188e+07
reached.threshold 8.661171e-03
steps 1.380000e+02
Intercept.to.1layhid1 1.391861e+01
t.to.1layhid1 2.917817e+00
rrr24.to.1layhid1 1.272637e+01
sshn.to.1layhid1 1.302440e+01
Intercept.to.1layhid2 1.418934e+01
t.to.1layhid2 3.010978e+00
rrr24.to.1layhid2 1.453077e+01
sshn.to.1layhid2 1.373876e+01
Intercept.to.1layhid3 1.458518e+01
t.to.1layhid3 3.028105e+00
rrr24.to.1layhid3 1.315952e+01
sshn.to.1layhid3 1.390079e+01
Intercept.to.1layhid4 1.255582e+01
t.to.1layhid4 2.520585e+00
rrr24.to.1layhid4 1.223544e+01
sshn.to.1layhid4 1.146831e+01
Intercept.to.u 8.018417e+00
1layhid1.to.u 8.222817e+00
1layhid2.to.u 8.355812e+00
1layhid3.to.u 9.095662e+00
1layhid4.to.u 8.024959e+00
> results_met <- neuralnet::compute(n2, test_met[,1:3])
"
I am confused why the error is so high ( 3.069188e+07). Is it a problem
regarding my codes?
Is the prediction made by this neural network accurate?
Sincerely
--
Best Regards
Javad Bayat
M.Sc. Environment Engineering
Alternative Mail: bayat194 at yahoo.com
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