Updating a vector using a while loop in R - r

Question

I got the following dataframe called nodes_df:
x y node_demand
1 2 62 3
2 80 25 14
3 36 88 1
4 57 23 14
5 33 17 19
6 76 43 2
7 77 85 14
8 94 6 6
10 59 72 6
. . . .
. . . .
. . . .
. . . .
45 60 84 8
46 35 100 5
47 38 2 1
48 9 9 7
50 1 58 2
I have to split this dataframe between hubs and clients.
hubs <- nodes_df[keep <- sample(1:total_nodes, requested_hubs, replace = FALSE),]
client_nodes <- nodes_df[-keep, ]
I need to randomly select 1 row at a time from clients_nodes and calculate the total node_demand, I need to keep adding rows until random_clients$node_demand exceedes 120.
random_clients <- client_nodes[sample(nrow(client_nodes), size = 1, replace = FALSE),]
I created the following variables and while loop
node_demand <- c(0)
cumulative_demand <- cumsum(node_demand)
client_nodes <- nodes_df[-keep, ]
last_node <- cumsum(cumulative_demand) >= max_supply_capacity
condition = TRUE
while(condition){
random_clients <- client_nodes[sample(nrow(client_nodes), size = 1, replace = FALSE),]
node_demand <- c(node_demand,random_clients$node_demand)
cumulative_demand <- cumsum(node_demand)
if(cumulative_demand <= max_supply_capacity){
condition == FALSE
}
}
The loop doesn't stop and I get the following return value:
cumulative_demand
[1] 0 14 20 26 27 35 49 50 68 79 97 100 101 104 109 118
[17] 119 137 150 164 178 185 188 191 208 209 219 222 227 246 252 272 (it carries on and on)
I am not sure why the loop doesn't stop despite the condition cumulative_demand <= max_supply_capacity being met.
Anybody could show me how to fix it?
I managed to fix it :).
I had to use ifelse() so R could evaluate the condition of a vector. The normal if() statement wouldn't work in this case
while(TRUE){
random_clients <- client_nodes[sample(nrow(client_nodes), size = 1, replace = FALSE),]
node_demand <- c(node_demand,random_clients$node_demand)
cumulative_demand <- cumsum(node_demand)
last_node <- (cumulative_demand <= max_supply_capacity)
ifelse(last_node == FALSE,break,next)
}

Answer 1

I had to use and ifelse() instead of an if() statement as shown in the problem description.