Find the closest enclosing FALSE value positions
Is there a more elegant way to solve this problem?
For every TRUE value I'm looking for the positions of the closest previous and following FALSE values.
data:
vec <- c(FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)
desired outcome: (something like)
pos start end
[1,] 2 1 4
[2,] 3 1 4
[3,] 5 4 6
explanation of the first row of the outcome:
- pos = 2, position of the first TRUE,
- start = 1, position of the closest FALSE in front of pos = 2
- end = 4, position of the closest FALSE after pos = 2.
Already working solution:
pos = which(vec)
f_pos = which(!vec)
t(
sapply(pos, function(x){ s <- rev(f_pos[f_pos < x])[1]; e <- f_pos[x < f_pos][1]; return(data.frame(pos = x, start = s, end = e)) })
)
r
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
add a comment |
Is there a more elegant way to solve this problem?
For every TRUE value I'm looking for the positions of the closest previous and following FALSE values.
data:
vec <- c(FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)
desired outcome: (something like)
pos start end
[1,] 2 1 4
[2,] 3 1 4
[3,] 5 4 6
explanation of the first row of the outcome:
- pos = 2, position of the first TRUE,
- start = 1, position of the closest FALSE in front of pos = 2
- end = 4, position of the closest FALSE after pos = 2.
Already working solution:
pos = which(vec)
f_pos = which(!vec)
t(
sapply(pos, function(x){ s <- rev(f_pos[f_pos < x])[1]; e <- f_pos[x < f_pos][1]; return(data.frame(pos = x, start = s, end = e)) })
)
r
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
what ifvecended withTRUE?
– Cath
Nov 14 '18 at 9:05
good question, my solution gives backNA. If TRUE values are on the borders. That's fine.
– Andre Elrico
Nov 14 '18 at 9:07
add a comment |
Is there a more elegant way to solve this problem?
For every TRUE value I'm looking for the positions of the closest previous and following FALSE values.
data:
vec <- c(FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)
desired outcome: (something like)
pos start end
[1,] 2 1 4
[2,] 3 1 4
[3,] 5 4 6
explanation of the first row of the outcome:
- pos = 2, position of the first TRUE,
- start = 1, position of the closest FALSE in front of pos = 2
- end = 4, position of the closest FALSE after pos = 2.
Already working solution:
pos = which(vec)
f_pos = which(!vec)
t(
sapply(pos, function(x){ s <- rev(f_pos[f_pos < x])[1]; e <- f_pos[x < f_pos][1]; return(data.frame(pos = x, start = s, end = e)) })
)
r
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
Is there a more elegant way to solve this problem?
For every TRUE value I'm looking for the positions of the closest previous and following FALSE values.
data:
vec <- c(FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)
desired outcome: (something like)
pos start end
[1,] 2 1 4
[2,] 3 1 4
[3,] 5 4 6
explanation of the first row of the outcome:
- pos = 2, position of the first TRUE,
- start = 1, position of the closest FALSE in front of pos = 2
- end = 4, position of the closest FALSE after pos = 2.
Already working solution:
pos = which(vec)
f_pos = which(!vec)
t(
sapply(pos, function(x){ s <- rev(f_pos[f_pos < x])[1]; e <- f_pos[x < f_pos][1]; return(data.frame(pos = x, start = s, end = e)) })
)
r
r
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
edited Nov 14 '18 at 9:22
Konrad Rudolph
394k1017791025
394k1017791025
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
asked Nov 14 '18 at 8:59
Andre Elrico
5,63311027
5,63311027
what ifvecended withTRUE?
– Cath
Nov 14 '18 at 9:05
good question, my solution gives backNA. If TRUE values are on the borders. That's fine.
– Andre Elrico
Nov 14 '18 at 9:07
add a comment |
what ifvecended withTRUE?
– Cath
Nov 14 '18 at 9:05
good question, my solution gives backNA. If TRUE values are on the borders. That's fine.
– Andre Elrico
Nov 14 '18 at 9:07
what if
vec ended with TRUE?– Cath
Nov 14 '18 at 9:05
what if
vec ended with TRUE?– Cath
Nov 14 '18 at 9:05
good question, my solution gives back
NA. If TRUE values are on the borders. That's fine.– Andre Elrico
Nov 14 '18 at 9:07
good question, my solution gives back
NA. If TRUE values are on the borders. That's fine.– Andre Elrico
Nov 14 '18 at 9:07
add a comment |
2 Answers
2
active
oldest
votes
Using findInterval
pos <- which(vec)
b <- which(!vec)
ix <- findInterval(pos, b)
cbind(pos, from = b[ix], to = b[ix + 1])
# pos from to
# [1,] 2 1 4
# [2,] 3 1 4
# [3,] 5 4 6
If we stretch your "something like" slightly, a simple cut will do:
data.frame(pos, rng = cut(pos, b))
# pos rng
# 1 2 (1,4]
# 2 3 (1,4]
# 3 5 (4,6]
If the vector ends with TRUE, the findInterval solution will give NA in 'to' column. In cut, the last 'interval' is then coded as NA.
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
b[ix + 1]very clever
– Andre Elrico
Nov 14 '18 at 9:35
add a comment |
You can do as if FALSE defined intervals and use data.table::foverlaps to find the right ones:
library(data.table)
# put your objects in data.tables:
f_pos_inter <- data.table(start=head(f_pos, -1), end=tail(f_pos, -1))
pos_inter <- data.table(start=pos, end=pos)
# define the keys:
setkeyv(pos_inter, c("start", "end")); setkeyv(f_pos_inter, c("start", "end"))
res <- foverlaps(pos_inter, f_pos_inter)
# start end i.start i.end
#1: 1 4 2 2
#2: 1 4 3 3
#3: 4 6 5 5
You can further reorder the columns and keep only the ones you need:
res[, i.end:=NULL]
setcolorder(res, c(3, 1, 2))
setnames(res, "i.start", "pos")
res
# pos start end
#1: 2 1 4
#2: 3 1 4
#3: 5 4 6
N.B: this will give NA in both columns start and end if vec ends with TRUE
answered Nov 14 '18 at 9:10
Cath
19.7k43464
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53296330%2ffind-the-closest-enclosing-false-value-positions%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Using findInterval
pos <- which(vec)
b <- which(!vec)
ix <- findInterval(pos, b)
cbind(pos, from = b[ix], to = b[ix + 1])
# pos from to
# [1,] 2 1 4
# [2,] 3 1 4
# [3,] 5 4 6
If we stretch your "something like" slightly, a simple cut will do:
data.frame(pos, rng = cut(pos, b))
# pos rng
# 1 2 (1,4]
# 2 3 (1,4]
# 3 5 (4,6]
If the vector ends with TRUE, the findInterval solution will give NA in 'to' column. In cut, the last 'interval' is then coded as NA.
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
b[ix + 1]very clever
– Andre Elrico
Nov 14 '18 at 9:35
add a comment |
Using findInterval
pos <- which(vec)
b <- which(!vec)
ix <- findInterval(pos, b)
cbind(pos, from = b[ix], to = b[ix + 1])
# pos from to
# [1,] 2 1 4
# [2,] 3 1 4
# [3,] 5 4 6
If we stretch your "something like" slightly, a simple cut will do:
data.frame(pos, rng = cut(pos, b))
# pos rng
# 1 2 (1,4]
# 2 3 (1,4]
# 3 5 (4,6]
If the vector ends with TRUE, the findInterval solution will give NA in 'to' column. In cut, the last 'interval' is then coded as NA.
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
b[ix + 1]very clever
– Andre Elrico
Nov 14 '18 at 9:35
add a comment |
Using findInterval
pos <- which(vec)
b <- which(!vec)
ix <- findInterval(pos, b)
cbind(pos, from = b[ix], to = b[ix + 1])
# pos from to
# [1,] 2 1 4
# [2,] 3 1 4
# [3,] 5 4 6
If we stretch your "something like" slightly, a simple cut will do:
data.frame(pos, rng = cut(pos, b))
# pos rng
# 1 2 (1,4]
# 2 3 (1,4]
# 3 5 (4,6]
If the vector ends with TRUE, the findInterval solution will give NA in 'to' column. In cut, the last 'interval' is then coded as NA.
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
Using findInterval
pos <- which(vec)
b <- which(!vec)
ix <- findInterval(pos, b)
cbind(pos, from = b[ix], to = b[ix + 1])
# pos from to
# [1,] 2 1 4
# [2,] 3 1 4
# [3,] 5 4 6
If we stretch your "something like" slightly, a simple cut will do:
data.frame(pos, rng = cut(pos, b))
# pos rng
# 1 2 (1,4]
# 2 3 (1,4]
# 3 5 (4,6]
If the vector ends with TRUE, the findInterval solution will give NA in 'to' column. In cut, the last 'interval' is then coded as NA.
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
edited Nov 14 '18 at 10:07
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
answered Nov 14 '18 at 9:24
Henrik
40.8k992107
40.8k992107
b[ix + 1]very clever
– Andre Elrico
Nov 14 '18 at 9:35
add a comment |
b[ix + 1]very clever
– Andre Elrico
Nov 14 '18 at 9:35
b[ix + 1] very clever– Andre Elrico
Nov 14 '18 at 9:35
b[ix + 1] very clever– Andre Elrico
Nov 14 '18 at 9:35
add a comment |
You can do as if FALSE defined intervals and use data.table::foverlaps to find the right ones:
library(data.table)
# put your objects in data.tables:
f_pos_inter <- data.table(start=head(f_pos, -1), end=tail(f_pos, -1))
pos_inter <- data.table(start=pos, end=pos)
# define the keys:
setkeyv(pos_inter, c("start", "end")); setkeyv(f_pos_inter, c("start", "end"))
res <- foverlaps(pos_inter, f_pos_inter)
# start end i.start i.end
#1: 1 4 2 2
#2: 1 4 3 3
#3: 4 6 5 5
You can further reorder the columns and keep only the ones you need:
res[, i.end:=NULL]
setcolorder(res, c(3, 1, 2))
setnames(res, "i.start", "pos")
res
# pos start end
#1: 2 1 4
#2: 3 1 4
#3: 5 4 6
N.B: this will give NA in both columns start and end if vec ends with TRUE
answered Nov 14 '18 at 9:10
Cath
19.7k43464
add a comment |
You can do as if FALSE defined intervals and use data.table::foverlaps to find the right ones:
library(data.table)
# put your objects in data.tables:
f_pos_inter <- data.table(start=head(f_pos, -1), end=tail(f_pos, -1))
pos_inter <- data.table(start=pos, end=pos)
# define the keys:
setkeyv(pos_inter, c("start", "end")); setkeyv(f_pos_inter, c("start", "end"))
res <- foverlaps(pos_inter, f_pos_inter)
# start end i.start i.end
#1: 1 4 2 2
#2: 1 4 3 3
#3: 4 6 5 5
You can further reorder the columns and keep only the ones you need:
res[, i.end:=NULL]
setcolorder(res, c(3, 1, 2))
setnames(res, "i.start", "pos")
res
# pos start end
#1: 2 1 4
#2: 3 1 4
#3: 5 4 6
N.B: this will give NA in both columns start and end if vec ends with TRUE
answered Nov 14 '18 at 9:10
Cath
19.7k43464
add a comment |
You can do as if FALSE defined intervals and use data.table::foverlaps to find the right ones:
library(data.table)
# put your objects in data.tables:
f_pos_inter <- data.table(start=head(f_pos, -1), end=tail(f_pos, -1))
pos_inter <- data.table(start=pos, end=pos)
# define the keys:
setkeyv(pos_inter, c("start", "end")); setkeyv(f_pos_inter, c("start", "end"))
res <- foverlaps(pos_inter, f_pos_inter)
# start end i.start i.end
#1: 1 4 2 2
#2: 1 4 3 3
#3: 4 6 5 5
You can further reorder the columns and keep only the ones you need:
res[, i.end:=NULL]
setcolorder(res, c(3, 1, 2))
setnames(res, "i.start", "pos")
res
# pos start end
#1: 2 1 4
#2: 3 1 4
#3: 5 4 6
N.B: this will give NA in both columns start and end if vec ends with TRUE
answered Nov 14 '18 at 9:10
Cath
19.7k43464
You can do as if FALSE defined intervals and use data.table::foverlaps to find the right ones:
library(data.table)
# put your objects in data.tables:
f_pos_inter <- data.table(start=head(f_pos, -1), end=tail(f_pos, -1))
pos_inter <- data.table(start=pos, end=pos)
# define the keys:
setkeyv(pos_inter, c("start", "end")); setkeyv(f_pos_inter, c("start", "end"))
res <- foverlaps(pos_inter, f_pos_inter)
# start end i.start i.end
#1: 1 4 2 2
#2: 1 4 3 3
#3: 4 6 5 5
You can further reorder the columns and keep only the ones you need:
res[, i.end:=NULL]
setcolorder(res, c(3, 1, 2))
setnames(res, "i.start", "pos")
res
# pos start end
#1: 2 1 4
#2: 3 1 4
#3: 5 4 6
N.B: this will give NA in both columns start and end if vec ends with TRUE
answered Nov 14 '18 at 9:10
Cath
19.7k43464
edited Nov 14 '18 at 9:19
answered Nov 14 '18 at 9:10
Cath
19.7k43464
answered Nov 14 '18 at 9:10
Cath
19.7k43464
answered Nov 14 '18 at 9:10
Cath
19.7k43464
19.7k43464
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53296330%2ffind-the-closest-enclosing-false-value-positions%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
what if
vecended withTRUE?– Cath
Nov 14 '18 at 9:05
good question, my solution gives back
NA. If TRUE values are on the borders. That's fine.– Andre Elrico
Nov 14 '18 at 9:07