warning: number of items to replace is not a multiple of replacement length

I am working the R language. I am trying to follow this tutorial here (A quick tour of GA ) on function optimization.

I created some data for this example:

``````#load libraries
library(dplyr)
library(GA)

# create some data for this example
a1 = rnorm(1000,100,10)
b1 = rnorm(1000,100,5)
c1 = sample.int(1000, 1000, replace = TRUE)
train_data = data.frame(a1,b1,c1)
``````

I defined the following function ("funct_set") over here:

``````funct_set <- function (x) {
x1 <- x[1]; x2 <- x[2]; x3 <- x[3] ; x4 <- x[4]
f <- numeric(4)

#bin data according to random criteria
train_data <- train_data %>%
mutate(cat = ifelse(a1 <= x1 & b1 <= x3, "a",
ifelse(a1 <= x2 & b1 <= x4, "b", "c")))

train_data\$cat = as.factor(train_data\$cat)

#new splits
a_table = train_data %>%
filter(cat == "a") %>%
select(a1, b1, c1, cat)

b_table = train_data %>%
filter(cat == "b") %>%
select(a1, b1, c1, cat)

c_table = train_data %>%
filter(cat == "c") %>%
select(a1, b1, c1, cat)

#calculate  quantile ("quant") for each bin

table_a = data.frame(a_table%>% group_by(cat) %>%
mutate(quant = ifelse(c1 > x[5],1,0 )))

table_b = data.frame(b_table%>% group_by(cat) %>%
mutate(quant = ifelse(c1 > x[6],1,0 )))

table_c = data.frame(c_table%>% group_by(cat) %>%
mutate(quant = ifelse(c1 > x[7],1,0 )))

f[1] = -mean(table_a\$quant)
f[2] = -mean(table_b\$quant)
f[3] = -mean(table_c\$quant)

#group all tables

final_table = rbind(table_a, table_b, table_c)
# calculate the total mean : this is what needs to be optimized

f[4] = -mean(final_table\$quant)

return (f);
}
``````

Then, I ran the optimization algorithm:

``````GA <- ga(type = "real-valued",
fitness = funct_set,
lower = c(80, 1, 80, 1, 90,180, 365), upper = c(100, 20, 100, 20, 140,400,720),
popSize = 50, maxiter = 20, run = 20)
``````

This successfully runs, e.g. :

``````GA | iter = 1 | Mean = -0.9686663 | Best = -0.8636364
GA | iter = 2 | Mean = -0.9408230 | Best = -0.8571429
GA | iter = 3 | Mean = -0.9107766 | Best = -0.8571429
GA | iter = 4 | Mean = -0.8995899 | Best = -0.8571429

etc
``````

But this produces the following warning:

``````There were 50 or more warnings (use warnings() to see the first 50)
``````

When I view the warnings, I see this warning appear multiple times:

``````#view warnings
warnings()

Warning messages:
1: In Fitness[i] <- fit :
number of items to replace is not a multiple of replacement length
2: In Fitness[i] <- fit :
number of items to replace is not a multiple of replacement length
3: In Fitness[i] <- fit :
number of items to replace is not a multiple of replacement length

etc
``````

Does anyone know why these warnings are being produced? Is there a way to avoid these warnings?

Thanks

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