How to convert loop output to a vector?

Question

I extract certain values out of dataset Z (the positions are given in dataset A) using a loop function.

#Exemplary datasets
Z <- data.frame(Depth=c(0.02,0.04,0.06,0.08,0.10,0.12,0.14,0.16,0.18,0.2), 
Value=c(10,12,5,6,7,4,3,2,11,13))
A <- data.frame(Depth=c(0.067, 0.155))

for (n in c(1:nrow(A)))
+ {find_values <- Z$Value[Z$Depth>=A$Depth[n]][1]
+ print(find_values)}

#Result
[1] 6
[1] 2

The result seems to consist of values in two seperate vectors. How can I merge them in an easy way to one vector as follows?

[1] 6, 2

Thanks in advance!

Ronak Shah · Accepted Answer · 2019-05-22 12:29:01Z

1

For your code to work as it is you can store them using index in for loop

for (n in seq_len(nrow(A))) {
   find_values[n] <- Z$Value[Z$Depth>=A$Depth[n]][1]
}
find_values
#[1] 6 2

However, you can simplify this with sapply by doing

sapply(A$Depth, function(x) Z$Value[which.max(Z$Depth >= x)])
#[1] 6 2

answered May 22, 2019 at 12:29

Ronak Shah

391k20 gold badges173 silver badges237 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

akrun · Accepted Answer · 2019-05-22 14:51:01Z

0

We can use a vectorized approach

Z$Value[findInterval(A$Depth, Z$Depth) + 1]
#[1] 6 2

answered May 22, 2019 at 14:51

akrun

891k38 gold badges590 silver badges700 bronze badges

Collectives™ on Stack Overflow

How to convert loop output to a vector?

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related