replace NAs with division of two columns - r

I have a data.frame that looks like:
a b c d
1 2 NA 1
NA 2 2 1
3 2 NA 1
NA NA 20 2
And I want to replace the NAs with c / d (and delete c and d) to look like:
a b
1 2
2 2
3 2
10 10
Some background: d is a sum of NAs in that particular row.
I don't know the names of the columns, so I tried a few variations of things like:
df2[, 1:(length(colnames(df2)) - 2)][is.na(df2[, 1:(length(colnames(df2)) - 2)])] = df2$c / df2$d
but got:
Error in `[<-.data.frame`(`*tmp*`, is.na(df2[, 1:(length(colnames(df2)) - :
'value' is the wrong length

Here's a way you can do this with dplyr.
library(dplyr)
df <- tibble(
a = c(1, NA, 3, NA),
b = c(2, 2, 2, NA),
c = c(NA, 2, NA, 20L),
d = c(1, 1, 1, 2)
)
df %>%
mutate_at(vars(-c, -d), funs(if_else(is.na(.), c / d, .))) %>%
select(-c, -d)
#> # A tibble: 4 x 2
#> a b
#> <dbl> <dbl>
#> 1 1 2
#> 2 2 2
#> 3 3 2
#> 4 10 10
You can specify the variables in the vars() call using any of the functions from ?dplyr::select_helpers. These could be regex, a simple vector of names, or you can just use all columns except c and d (as I've changed this example to now).

library(data.table)
data<-fread("a b c d
1 2 NA 1
NA 2 2 1
3 2 NA 1
NA NA 20 2")
names_to_loop<-names(data)
names_to_loop<-names_to_loop[names_to_loop!="c"&names_to_loop!="d"]
for (ntl in names_to_loop){
set(data,j=ntl,value=ifelse(is.na(data[[ntl]]),data[["c"]]/data[["d"]],data[[ntl]]))
}
data[,c:=NULL]
data[,d:=NULL]
> data
a b
1: 1 2
2: 2 2
3: 3 2
4: 10 10

Related

Left join by group and condition (`tidyverse` or `data.table`)

I have a very large data frame that includes integer columns state and state_cyclen. Every row is a gameframe, while state describes the state a game is in at that frame and state_cyclen is coded to indicate n occurrence of that state (it is basically data.table::rleid(state)). Conditioning on state and cycling by state_cyclen I need to import several columns from other definitions data frames. Definition data frames store properties about state and their row ordering informs on the way these properties are cycled throughout the game (players encounter each game state many times).
A minimal example of the long data that should be left joined:
data <- data.frame(
state = c(1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3, 3, 4, 4, 3, 3),
state_cyclen = c(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 1, 1, 4, 4)
)
data
#> state state_cyclen
#> 1 1 1
#> 2 1 1
#> 3 2 1
#> 4 2 1
#> 5 3 1
#> 6 3 1
#> 7 1 2
#> 8 1 2
#> 9 2 2
#> 10 2 2
#> 11 3 2
#> 12 3 2
#> 13 2 3
#> 14 2 3
#> 15 3 3
#> 16 3 3
#> 17 3 3
#> 18 4 1
#> 19 4 1
#> 20 3 4
#> 21 3 4
Minimal example for definition data frames storing the ordering:
def_one <- data.frame(
prop = letters[1:3],
others = LETTERS[1:3]
)
def_two <- data.frame(
prop = letters[4:10],
others = LETTERS[4:10]
)
def_three <- data.frame(
prop = letters[11:12],
others = LETTERS[11:12]
)
I have a solution written in base R that gives the desired output, but it's neither very readable, nor probably very efficient.
# Add empty columns
data$prop <- NA
data$others <- NA
# Function that recycles numeric vector bounded by a upper limit
bounded_vec_recyc <- function(vec, n) if(n == 1) vec else (vec - 1) %% n + 1
# My solution
vec_pos_one <- data[data[, "state"] == 1, ]$state_cyclen
vec_pos_one <- bounded_vec_recyc(vec_pos_one, n = nrow(def_one))
data[data[, "state"] == 1, ][, c("prop", "others")] <- def_one[vec_pos_one,]
vec_pos_two <- data[data[, "state"] == 2, ]$state_cyclen
vec_pos_two <- bounded_vec_recyc(vec_pos_two, n = nrow(def_two))
data[data[, "state"] == 2, ][, c("prop", "others")] <- def_two[vec_pos_two,]
vec_pos_three <- data[data[, "state"] == 3, ]$state_cyclen
vec_pos_three <- bounded_vec_recyc(vec_pos_three, n = nrow(def_three))
data[data[, "state"] == 3, ][, c("prop", "others")] <- def_three[vec_pos_three,]
data
#> state state_cyclen prop others
#> 1 1 1 a A
#> 2 1 1 a A
#> 3 2 1 d D
#> 4 2 1 d D
#> 5 3 1 k K
#> 6 3 1 k K
#> 7 1 2 b B
#> 8 1 2 b B
#> 9 2 2 e E
#> 10 2 2 e E
#> 11 3 2 l L
#> 12 3 2 l L
#> 13 2 3 f F
#> 14 2 3 f F
#> 15 3 3 k K
#> 16 3 3 k K
#> 17 3 3 k K
#> 18 4 1 <NA> <NA>
#> 19 4 1 <NA> <NA>
#> 20 3 4 l L
#> 21 3 4 l L
Created on 2022-08-30 with reprex v2.0.2
TLDR: As you can see, I am basically trying to merge one by one these definition data frames to the main data frame on corresponding state by recycling the rows of the definition data frame while retaining their order, using the state_cyclen column to keep track of occurrences of each state throughout the game.
Is there a way to do this within the tidyverse or data.table that is faster or at least easier to read? I need this to be quite fast as I have many such gameframe files (in the hundreds) and they are lengthy (hundreds of thousands of rows).
P.S. Not sure if title is adequate for the operations I am doing, as I can imagine multiple ways of implementation. Edits on it are welcome.
Here, I make a lookup table combining the three sources. Then I join the data with the number of rows for each state, modify the state_cyclen in data using modulo with that number to be within the lookup range, then join.
library(tidyverse)
def <- bind_rows(def_one, def_two, def_three, .id = "state") %>%
mutate(state = as.numeric(state)) %>%
group_by(state) %>%
mutate(state_cyclen_adj = row_number()) %>%
ungroup()
data %>%
left_join(def %>% count(state)) %>%
# eg for row 15 we change 3 to 1 since the lookup table only has 2 rows
mutate(state_cyclen_adj = (state_cyclen - 1) %% n + 1) %>%
left_join(def)
Joining, by = "state"
Joining, by = c("state", "state_cyclen_adj")
state state_cyclen n state_cyclen_adj prop others
1 1 1 3 1 a A
2 1 1 3 1 a A
3 2 1 7 1 d D
4 2 1 7 1 d D
5 3 1 2 1 k K
6 3 1 2 1 k K
7 1 2 3 2 b B
8 1 2 3 2 b B
9 2 2 7 2 e E
10 2 2 7 2 e E
11 3 2 2 2 l L
12 3 2 2 2 l L
13 2 3 7 3 f F
14 2 3 7 3 f F
15 3 3 2 1 k K
16 3 3 2 1 k K
17 3 3 2 1 k K
18 4 1 NA NA <NA> <NA>
19 4 1 NA NA <NA> <NA>
20 3 4 2 2 l L
21 3 4 2 2 l L
Here is a data.table solution. Not sure it is easier to read, but pretty sure it is more efficient:
library(data.table)
dt <- rbind(setDT(def_one)[,state := 1],
setDT(def_two)[,state := 2],
setDT(def_three)[,state := 3])
dt[,state_cyclen := 1:.N,by = state]
data <- setDT(data)
data[dt[,.N,by = state],
state_cyclen := bounded_vec_recyc(state_cyclen,i.N),
on = "state",
by = .EACHI]
dt[data,on = c("state","state_cyclen")]
prop others state state_cyclen
1: a A 1 1
2: a A 1 1
3: d D 2 1
4: d D 2 1
5: k K 3 1
6: k K 3 1
7: b B 1 2
8: b B 1 2
9: e E 2 2
10: e E 2 2
11: l L 3 2
12: l L 3 2
13: f F 2 3
14: f F 2 3
15: k K 3 1
16: k K 3 1
17: k K 3 1
18: <NA> <NA> 4 1
19: <NA> <NA> 4 1
20: l L 3 2
21: l L 3 2
prop others state state_cyclen
By step:
I bind the def_one, def_two and def_three dataframes to create a data.table with the variable you need to merge
dt <- rbind(setDT(def_one)[,state := 1],
setDT(def_two)[,state := 2],
setDT(def_three)[,state := 3])
dt[,state_cyclen := 1:.N,by = state]
In case you want to merge a lot of dataframes, you can use rbindlist and a list of data.tables.
I then modify your state_cyclen in data to do the same recycling than you:
dt[,.N,by = state]
state N
1: 1 3
2: 2 7
3: 3 2
gives the lengths you use to define your recycling.
data[dt[,.N,by = state],
state_cyclen := bounded_vec_recyc(state_cyclen,i.N),
on = "state",
by = .EACHI]
I use the by = .EACHI to modify the variable for each group during the merge, using the N variable from dt[,.N,by = state]
Then I just have to do the left join:
dt[data,on = c("state","state_cyclen")]
An option with nest/unnest
library(dplyr)
library(tidyr)
data %>%
nest_by(state) %>%
left_join(tibble(state = 1:3, dat = list(def_one, def_two, def_three))) %>%
mutate(data = list(bind_cols(data, if(!is.null(dat))
dat[data %>%
pull(state_cyclen) %>%
bounded_vec_recyc(., nrow(dat)),] else NULL)), dat = NULL) %>%
ungroup %>%
unnest(data)
-output
# A tibble: 21 × 4
state state_cyclen prop others
<dbl> <dbl> <chr> <chr>
1 1 1 a A
2 1 1 a A
3 1 2 b B
4 1 2 b B
5 2 1 d D
6 2 1 d D
7 2 2 e E
8 2 2 e E
9 2 3 f F
10 2 3 f F
# … with 11 more rows

R - How to operate on different columns for each row based on an extra-column containing the names of the columns to be used for operation

I am new to R. I would like to calculate the mean for each row of a dataframe, but using different subset of columns for each row. I have two extra-columns providing me the names of the column that represent the "start" and the "end" that I should use to calculate each mean, respectively.
Let's take this example
dframe <- data.frame(a=c("2","3","4", "2"), b=c("1","3","6", "2"), c=c("4","5","6", "3"), d=c("4","2","8", "5"), e=c("a", "c", "a", "b"), f=c("c", "d", "d", "c"))
dframe
Which provides the following dataframe:
a b c d e f
1 2 1 4 4 a c
2 3 3 5 2 c d
3 4 6 6 8 a d
4 2 2 3 5 b c
The columns e and f represent the first and last column I use to calculate the mean for each row.
For example, on line 1, the mean would be calculated including column a, b, c ((2+1+4)/3 -> 2.3)
So I would like to obtain the following output:
a b c d e f mean
1 2 1 4 4 a c 2.3
2 3 3 5 2 c d 3.5
3 4 6 6 8 a d 6
4 2 2 3 5 b c 2.5
I learnt how to create the indices, and I want then to use RowMeans, but I cannot find the correct arguments.
dframe %>%
mutate(e_indice = match(e, colnames(dframe)))%>%
mutate(f_indice = match(f, colnames(dframe)))%>%
mutate(mean = RowMeans(????, na.rm = TRUE))
Thanks a lot for your help
One dplyr option could be:
dframe %>%
rowwise() %>%
mutate(mean = rowMeans(cur_data()[match(e, names(.)):match(f, names(.))]))
a b c d e f mean
<dbl> <dbl> <dbl> <dbl> <chr> <chr> <dbl>
1 2 1 4 4 a c 2.33
2 3 3 5 2 c d 3.5
3 4 6 6 8 a d 6
4 2 2 3 5 b c 2.5
I would define a helper function that lets you slice the indices you want
from a matrix.
rowSlice <- function(x, start, stop) {
replace(x, col(x) < start | col(x) > stop, NA)
}
rowSlice(matrix(1, 4, 4), c(1, 3, 1, 2), c(3, 4, 4, 3))
#> [,1] [,2] [,3] [,4]
#> [1,] 1 1 1 NA
#> [2,] NA NA 1 1
#> [3,] 1 1 1 1
#> [4,] NA 1 1 NA
Then use across() to select the relvant columns, slice them,
and take the rowMeans().
library(dplyr)
dframe <- data.frame(
a = c(2, 3, 4, 2),
b = c(1, 3, 6, 2),
c = c(4, 5, 6, 3),
d = c(4, 2, 8, 5),
e = c("a", "c", "a", "b"),
f = c("c", "d", "d", "c")
)
dframe %>%
mutate(ei = match(e, colnames(dframe))) %>%
mutate(fi = match(f, colnames(dframe))) %>%
mutate(
mean = across(a:d) %>%
rowSlice(ei, fi) %>%
rowMeans(na.rm = TRUE)
)
#> a b c d e f ei fi mean
#> 1 2 1 4 4 a c 1 3 2.333333
#> 2 3 3 5 2 c d 3 4 3.500000
#> 3 4 6 6 8 a d 1 4 6.000000
#> 4 2 2 3 5 b c 2 3 2.500000
A base R solution. First, set columns to numeric. Then create a list of the columns on which to apply the mean. Then apply mean on selected columns.
s <- mapply(seq, match(dframe$e, colnames(dframe)), match(dframe$f, colnames(dframe)))
dframe$mean <- lapply(seq(nrow(dframe)), function(x) rowMeans(dframe[x, s[[x]]]))
a b c d e f mean
1 2 1 4 4 a c 2.333333
2 3 3 5 2 c d 3.5
3 4 6 6 8 a d 6
4 2 2 3 5 b c 2.5
A base R approach using apply
dframe$mean <- apply(dframe, 1, function(x)
mean(as.numeric(x[which(names(x) == x["e"]) : which(names(x) == x["f"])])))
dframe
a b c d e f mean
1 2 1 4 4 a c 2.333333
2 3 3 5 2 c d 3.500000
3 4 6 6 8 a d 6.000000
4 2 2 3 5 b c 2.500000

Expand dataframe in R by columns having different ID values

I have the following data frame in R
df1 <- data.frame(
"ID" = c("A", "B", "A", "B"),
"Value" = c(1, 2, 5, 5),
"freq" = c(1, 3, 5, 3)
)
I wish to obtain the following data frame
Value freq ID
1 1 A
2 NA A
3 NA A
4 NA A
5 1 A
1 NA B
2 2 B
3 NA B
4 NA B
5 5 B
I have tried the following code
library(tidyverse)
df_new <- bind_cols(df1 %>%
select(Value, freq, ID) %>%
complete(., expand(.,
Value = min(df1$Value):max(df1$Value))),)
I am getting the following output
Value freq ID
<dbl> <dbl> <fct>
1 1 A
2 3 B
3 NA NA
4 NA NA
5 5 A
5 3 B
I request someone to help me.
Using tidyr::full_seq we can find the full version of Value but nesting(full_seq(Value,1) will return an error:
Error: by can't contain join column full_seq(Value, 1) which is missing from RHS
so we need to add a name, hence nesting(Value=full_seq(Value,1)
library(tidyr)
df1 %>% complete(ID, nesting(Value=full_seq(Value,1)))
# A tibble: 10 x 3
ID Value freq
<fct> <dbl> <dbl>
1 A 1. 1.
2 A 2. NA
3 A 3. NA
4 A 4. NA
5 A 5. 5.
6 B 1. NA
7 B 2. 3.
8 B 3. NA
9 B 4. NA
10 B 5. 3.
Using data.table:
library(data.table)
setDT(df1)
setkey(df1, ID, Value)
df1[CJ(ID = c("A", "B"), Value = 1:5)]
ID Value freq
1: A 1 1
2: A 2 NA
3: A 3 NA
4: A 4 NA
5: A 5 5
6: B 1 NA
7: B 2 3
8: B 3 NA
9: B 4 NA
10: B 5 3
Would the following approach work for you?
with(data = df1,
expr = {
data.frame(Value = rep(wrapr::seqi(min(Value), max(Value)), length(unique(ID))),
ID = unique(ID))
}) %>%
left_join(y = df1,
by = c("ID" = "ID", "Value" = "Value")) %>%
arrange(ID, Value)
Results
Value ID freq
1 1 A 1
2 2 A NA
3 3 A NA
4 4 A NA
5 5 A 5
6 1 B NA
7 2 B 3
8 3 B NA
9 4 B NA
10 5 B 3
Comments
If I'm following your example correctly, your ID group takes values from 1 to 5. If this is the case, my approach would be to generate that reading unique combinations of both from the original data frame.
The only variable that is carried from the original data frame is freq that may / may not be available for a given par ID-Value. I would join that variable via left_join (as you seem to like tidyverse)
In your example, you have freq variable with values 1,3,5 but then in the example you list 1,2,5? In my example, I took original freq and left join it. You can modify it further using normal dplyr pipeline, if this is something you intended to do.

Unequal rows in list from unstack() - how to create a dataframe

I am (trying) to do a Robust ANOVA analysis in R. This requires that my two variables are in a very specific format. Basically, the requirement is to unstack two columns in my current dataframe and form an outcome frequency dataframe based on the predictor (categorical variable). This would usually happen automatically using the unstack() function i.e.
newDataFrame <- unstack(oldDataFrame, scores ~ columns)
However, the list returned has unequal rows for each category. Here is an example:
$A
[1] 2 4 2 3 3
$B
[1] 3 3
$C
[1] 5
$D
[1] 4 4 3
A, B, C and D are my categories, and the numbers are the outcome. The outcome has to be 1, 2, 3, 4, 5 or 6.
What I am working towards is the category as the 'header' and the outcome as a reference column, with the frequencies as the other columns, such that the dataframe looks like this:
A B C D
1 NA NA NA NA
2 2 NA NA NA
3 2 2 NA 1
4 1 NA NA 2
5 NA NA 1 NA
6 NA NA NA NA
What I have tried:
On another SO post, I found this -
library(stringi)
res <- as.data.frame(t(stri_list2matrix(myUnstackedList)))
colnames(res) <- unique(unlist(sapply(myUnstackedList, names)))
Outcome:
res
1 2 4 2 3 3
2 3 3 <NA> <NA> <NA>
3 5 <NA> <NA> <NA> <NA>
4 4 4 3 <NA> <NA>
Note that the categories A, B, C, D have been changed to 1, 2, 3, 4
Also tried this (another SO post):
df <- as.data.frame(plyr::ldply(myUnstackedList, rbind))
Outcome:
df
outcome group score
2 A 2
3 A 2
4 A 1
3 B 2
etc
Any tips?
This gets you most of the way to your answer:
test <- list(A=c(2,4,2,3,3),
B=c(3,3),
C=c(5),
D=c(4,4,3))
test <- lapply(1:length(test), function(i){
x <- data.frame(names(test)[i], test[i],
stringsAsFactors=FALSE)
names(x) <- c("ID", "Value")
x})
test <- bind_rows(test) %>% table %>% as.data.frame
test <- spread(test, key=ID, value=Freq)
replace(test, test==0, NA)
I'm not sure what the issue was with your previous dplyr attempt, however, I offer
library(tidyr)
library(dplyr)
df <- tibble(
outcome = c(1:5, 1:2, 1, 1:3),
group = c(rep("A", 5), rep("B", 2), "C", rep("D", 3)),
score = c(2, 4, 2, 3, 3, 3, 3, 5, 4, 4, 3)
)
df %>%
group_by(outcome) %>%
spread(group, score) %>%
ungroup() %>%
select(-outcome)
# # A tibble: 5 x 4
# A B C D
# * <dbl> <dbl> <dbl> <dbl>
# 1 2 3 5 4
# 2 4 3 NA 4
# 3 2 NA NA 3
# 4 3 NA NA NA
# 5 3 NA NA NA

How to merge variables looping through by variable number in R

I have a dataframe with a lot of variables seen in multiple conditions. I'd like to merge each variable by condition.
The example data frame is a simplified version of what I have (3 variables over 2 conditions).
VAR.B_1 <- c(1, 2, 3, 4, 5, 'NA', 'NA', 'NA', 'NA', 'NA')
VAR.B_2 <- c(2, 2, 3, 4, 5,'NA', 'NA', 'NA', 'NA', 'NA')
VAR.B_3 <- c(1, 1, 1, 1, 1,'NA', 'NA', 'NA', 'NA', 'NA')
VAR.E_1 <- c(NA, NA, NA, NA, NA, 1, 1, 1, 1, 1)
VAR.E_2 <- c(NA, NA, NA, NA, NA, 1, 2, 3, 4, 5)
VAR.E_3 <- c(NA, NA, NA, NA, NA, 1, 1, 1, 1, 1)
Condition <- c("B", "B","B","B","B","E","E","E","E","E")
#Example dataset
data<-as.data.frame(cbind(VAR.B_1,VAR.B_2,VAR.B_3, VAR.E_1,VAR.E_2, VAR.E_3, Condition))
I want to end up with this, appended to the original data frame:
VAR_1 VAR_2 VAR_3
1 2 1
2 2 1
3 3 1
4 4 1
5 5 1
1 1 1
1 2 1
1 3 1
1 4 1
1 5 1
I understand that R won't work with i inside the variable name, but I have an example of the kind of for loop I was trying to do. I would rather not call variables by column location, since there will be a lot of variables.
##Example of how I want to merge - this code does not work
for(i in 1:3) {
data$VAR_[,i] <-ifelse(data$Condition == "B", VAR.B_[,i],
ifelse(data$Condition == "E", VAR.E_[,i], NA))
}
This might work for your situation:
library(tidyverse)
library(stringr)
data %>%
mutate_all(as.character) %>%
gather(key, value, -Condition) %>%
filter(!is.na(value), value != "NA") %>%
mutate(key = str_replace(key, paste0("\\.", Condition), "")) %>%
group_by(Condition, key) %>%
mutate(rowid = 1:n()) %>%
spread(key, value) %>%
bind_cols(data)
#> # A tibble: 10 x 12
#> # Groups: Condition [2]
#> Condition rowid VAR_1 VAR_2 VAR_3 VAR.B_1 VAR.B_2 VAR.B_3 VAR.E_1
#> <chr> <int> <chr> <chr> <chr> <fctr> <fctr> <fctr> <fctr>
#> 1 B 1 1 2 1 1 2 1 NA
#> 2 B 2 2 2 1 2 2 1 NA
#> 3 B 3 3 3 1 3 3 1 NA
#> 4 B 4 4 4 1 4 4 1 NA
#> 5 B 5 5 5 1 5 5 1 NA
#> 6 E 1 1 1 1 NA NA NA 1
#> 7 E 2 1 2 1 NA NA NA 1
#> 8 E 3 1 3 1 NA NA NA 1
#> 9 E 4 1 4 1 NA NA NA 1
#> 10 E 5 1 5 1 NA NA NA 1
#> # ... with 3 more variables: VAR.E_2 <fctr>, VAR.E_3 <fctr>,
#> # Condition1 <fctr>
data.frame(lapply(split.default(data[-NCOL(data)], gsub("\\D+", "", head(names(data), -1))),
function(a){
a = sapply(a, function(x) as.numeric(as.character(x)))
rowSums(a, na.rm = TRUE)
}))
# X1 X2 X3
#1 1 2 1
#2 2 2 1
#3 3 3 1
#4 4 4 1
#5 5 5 1
#6 1 1 1
#7 1 2 1
#8 1 3 1
#9 1 4 1
#10 1 5 1
#Warning messages:
#1: In FUN(X[[i]], ...) : NAs introduced by coercion
#2: In FUN(X[[i]], ...) : NAs introduced by coercion
#3: In FUN(X[[i]], ...) : NAs introduced by coercion
Your data appears to have two kinds of NA values in it. It has NA, or R's NA value, and it also has the string 'NA'. In my solution below, I replace both with zero, cast each column in the data frame to numeric, and then just sum together like-numbered VAR columns. Then, drop the original columns which you don't want anymore.
data <- as.data.frame(cbind(VAR.B_1,VAR.B_2,VAR.B_3, VAR.E_1,VAR.E_2, VAR.E_3),
stringsAsFactors=FALSE)
data[is.na(data)] <- 0
data[data == 'NA'] <- 0
data <- as.data.frame(lapply(data, as.numeric))
data$VAR_1 <- data$VAR.B_1 + data$VAR.E_1
data$VAR_2 <- data$VAR.B_2 + data$VAR.E_2
data$VAR_3 <- data$VAR.B_3 + data$VAR.E_3
data <- data[c("VAR_1", "VAR_2", "VAR_3")]
Demo

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