Save every iteration of for loop

Question

I have asked these question before and solve the problem with Saga's help. I am working on a simulation study. I have to reorganize my results and continue to analysis.

I have a data matrix contains may results like this

> data
It S  X     Y   F
1  1  0.5  0.8  2.39
1  2  0.3  0.2  1.56
2  1  1.56 2.13 1.48
3  1  2.08 1.05 2.14
3  2  1.56 2.04 2.45
.......

It shows iteration S shows second iteration working inside of IT X shows coordinate of X obtained from a method Y shows coordinate of Y obtained from a method F shows the F statistic.

My problem is I have to find minimum F value for every iteration. So I have to store every iteration on a different matrix or data frame and find minimum F value.

I have tried many things but not worked. Any help, idea will be appreciated.

EDIT: Updated table information

This was the solution:

library(dplyr)

data %>% group_by(It) %>% slice(which.min(F))

A tibble: 3 x 5

Groups: It [3]

 It     S     X     Y     F

1 1 2 0.30 0.20 1.56 2 2 1 1.56 2.13 1.48 3 3 1 2.08 1.05 2.14

However , I will continue another for loop and I want to select every X values providing above conditions.

For example when I use data$X[i] This code doesn't select to values of X (0.30, 1.56, 2.08). It selected original values from "data" before grouping. How can I solve this problem?

Can you provide a reproductible example https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example — Emmanuel-Lin, Sep 05 '17 at 13:51
What's your desired output? If finding minimum of `F` for each value of `It`, does `sapply(unique(data$It), function(i) min(subset(data, It == i)$F)` work? — tkmckenzie, Sep 05 '17 at 13:54

score 0 · Answer 1 · answered Sep 05 '17 at 13:56

0

I hope this is what you are expecting:

> library(dplyr)

> data %>% 
   group_by(It) %>% 
   slice(which.min(F))

# A tibble: 3 x 5
# Groups:   It [3]
     It     S     X     Y     F
  <dbl> <dbl> <dbl> <dbl> <dbl>
1     1     2  0.30  0.20  1.56
2     2     1  1.56  2.13  1.48
3     3     1  2.08  1.05  2.14

answered Sep 05 '17 at 13:56

Sagar

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This is exactly what I need. Would you write me again please? Because It didnt work on my progrramme @Sagar – Elen Sep 05 '17 at 14:19
I didn't get it. What do you want me to write again? Did you receive any error(s)? – Sagar Sep 05 '17 at 14:22
Sorry I understand what is wrong. My "data" is a matrix but as I understood it should be a tbl. And I dont know how o do it – Elen Sep 05 '17 at 14:30
Can you convert your `data` to a `data.frame`? `data <- as.data.frame(data)` – Sagar Sep 05 '17 at 14:33
It worked. I thought that converting data frame wont work. Thank you for helping me – Elen Sep 05 '17 at 14:35
Glad I could help !! – Sagar Sep 05 '17 at 14:37

Save every iteration of for loop

A tibble: 3 x 5

Groups: It [3]

1 Answers1