Creating sequences of activity points from GPS data
I created this pseudo code for this section from a paper by Schüssler, N., & Axhausen, K. (2009):
Flag an activity when the point density in a sequence of GPS points is higher than 15 points for at least two-third of the points and the sequence lasts for at least 10 points or 300 s.
Pseudo code:
1.Start at beginning of trip file
2.Create Seq of 10 observations
3. If (#PD>15)>⅔*length(Seq)
a.Create copy of Seq: Seq2
b.While ((#PD>15)>⅔*length(Seq2))
i.Mark all of Seq2 as A
ii.If start of Seq2 = start of file then break
iii.Add 1 observation to start of Seq2 from preceding observations
c.Create copy of Seq: Seq3
d.While ((#PD>15)>⅔*length(Seq3))
i.Mark all of Seq3 as A
ii.If end of Seq3 = end of file then break
iii.Add 1 observation to end of Seq3 from following observations
4.Step forward 1 observation and return to (2)
This is my code in R (trip is a data frame and every row represents 1-second movement, p_dens is density of point):
trip$label_dns<-"trip"
for ( i in (1:nrow(trip)))
{
c<-length(which(trip$p_dens[c(i:(i+9))]>=15))
if(c>=7)
{seq_2<-c(i:(i+9))
seq_3<-c(i:(i+9))
while(length(which(trip$p_dens[seq_2]>=15))> (2/3)*length(seq_2))
{trip$label_dns[seq_2]<-"activity"
if(seq_2[1]!=1) {seq_2<-c((seq_2[1]-1):(seq_2[length(seq_2)]))}}
while(length(which(trip$p_dens[seq_3]>=15))> (2/3)*length(seq_3))
{trip$label_dns[seq_3]<-"activity"
if(seq_3[length(seq_3)]!=nrow(trip)) {seq_3<-c((seq_3[1]):
(seq_3[length(seq_3)]+1))}}
}
}
My concern is that it gets stuck in an infinite loop because it has been running for 7 days now for 1700 trips (in total 2000 hr GPS data).
beginner algorithm time-limit-exceeded r
edited 30 mins ago
Jamal♦
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I created this pseudo code for this section from a paper by Schüssler, N., & Axhausen, K. (2009):
Flag an activity when the point density in a sequence of GPS points is higher than 15 points for at least two-third of the points and the sequence lasts for at least 10 points or 300 s.
Pseudo code:
1.Start at beginning of trip file
2.Create Seq of 10 observations
3. If (#PD>15)>⅔*length(Seq)
a.Create copy of Seq: Seq2
b.While ((#PD>15)>⅔*length(Seq2))
i.Mark all of Seq2 as A
ii.If start of Seq2 = start of file then break
iii.Add 1 observation to start of Seq2 from preceding observations
c.Create copy of Seq: Seq3
d.While ((#PD>15)>⅔*length(Seq3))
i.Mark all of Seq3 as A
ii.If end of Seq3 = end of file then break
iii.Add 1 observation to end of Seq3 from following observations
4.Step forward 1 observation and return to (2)
This is my code in R (trip is a data frame and every row represents 1-second movement, p_dens is density of point):
trip$label_dns<-"trip"
for ( i in (1:nrow(trip)))
{
c<-length(which(trip$p_dens[c(i:(i+9))]>=15))
if(c>=7)
{seq_2<-c(i:(i+9))
seq_3<-c(i:(i+9))
while(length(which(trip$p_dens[seq_2]>=15))> (2/3)*length(seq_2))
{trip$label_dns[seq_2]<-"activity"
if(seq_2[1]!=1) {seq_2<-c((seq_2[1]-1):(seq_2[length(seq_2)]))}}
while(length(which(trip$p_dens[seq_3]>=15))> (2/3)*length(seq_3))
{trip$label_dns[seq_3]<-"activity"
if(seq_3[length(seq_3)]!=nrow(trip)) {seq_3<-c((seq_3[1]):
(seq_3[length(seq_3)]+1))}}
}
}
My concern is that it gets stuck in an infinite loop because it has been running for 7 days now for 1700 trips (in total 2000 hr GPS data).
beginner algorithm time-limit-exceeded r
edited 30 mins ago
Jamal♦
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I created this pseudo code for this section from a paper by Schüssler, N., & Axhausen, K. (2009):
Flag an activity when the point density in a sequence of GPS points is higher than 15 points for at least two-third of the points and the sequence lasts for at least 10 points or 300 s.
Pseudo code:
1.Start at beginning of trip file
2.Create Seq of 10 observations
3. If (#PD>15)>⅔*length(Seq)
a.Create copy of Seq: Seq2
b.While ((#PD>15)>⅔*length(Seq2))
i.Mark all of Seq2 as A
ii.If start of Seq2 = start of file then break
iii.Add 1 observation to start of Seq2 from preceding observations
c.Create copy of Seq: Seq3
d.While ((#PD>15)>⅔*length(Seq3))
i.Mark all of Seq3 as A
ii.If end of Seq3 = end of file then break
iii.Add 1 observation to end of Seq3 from following observations
4.Step forward 1 observation and return to (2)
This is my code in R (trip is a data frame and every row represents 1-second movement, p_dens is density of point):
trip$label_dns<-"trip"
for ( i in (1:nrow(trip)))
{
c<-length(which(trip$p_dens[c(i:(i+9))]>=15))
if(c>=7)
{seq_2<-c(i:(i+9))
seq_3<-c(i:(i+9))
while(length(which(trip$p_dens[seq_2]>=15))> (2/3)*length(seq_2))
{trip$label_dns[seq_2]<-"activity"
if(seq_2[1]!=1) {seq_2<-c((seq_2[1]-1):(seq_2[length(seq_2)]))}}
while(length(which(trip$p_dens[seq_3]>=15))> (2/3)*length(seq_3))
{trip$label_dns[seq_3]<-"activity"
if(seq_3[length(seq_3)]!=nrow(trip)) {seq_3<-c((seq_3[1]):
(seq_3[length(seq_3)]+1))}}
}
}
My concern is that it gets stuck in an infinite loop because it has been running for 7 days now for 1700 trips (in total 2000 hr GPS data).
beginner algorithm time-limit-exceeded r
edited 30 mins ago
Jamal♦
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I created this pseudo code for this section from a paper by Schüssler, N., & Axhausen, K. (2009):
Flag an activity when the point density in a sequence of GPS points is higher than 15 points for at least two-third of the points and the sequence lasts for at least 10 points or 300 s.
Pseudo code:
1.Start at beginning of trip file
2.Create Seq of 10 observations
3. If (#PD>15)>⅔*length(Seq)
a.Create copy of Seq: Seq2
b.While ((#PD>15)>⅔*length(Seq2))
i.Mark all of Seq2 as A
ii.If start of Seq2 = start of file then break
iii.Add 1 observation to start of Seq2 from preceding observations
c.Create copy of Seq: Seq3
d.While ((#PD>15)>⅔*length(Seq3))
i.Mark all of Seq3 as A
ii.If end of Seq3 = end of file then break
iii.Add 1 observation to end of Seq3 from following observations
4.Step forward 1 observation and return to (2)
This is my code in R (trip is a data frame and every row represents 1-second movement, p_dens is density of point):
trip$label_dns<-"trip"
for ( i in (1:nrow(trip)))
{
c<-length(which(trip$p_dens[c(i:(i+9))]>=15))
if(c>=7)
{seq_2<-c(i:(i+9))
seq_3<-c(i:(i+9))
while(length(which(trip$p_dens[seq_2]>=15))> (2/3)*length(seq_2))
{trip$label_dns[seq_2]<-"activity"
if(seq_2[1]!=1) {seq_2<-c((seq_2[1]-1):(seq_2[length(seq_2)]))}}
while(length(which(trip$p_dens[seq_3]>=15))> (2/3)*length(seq_3))
{trip$label_dns[seq_3]<-"activity"
if(seq_3[length(seq_3)]!=nrow(trip)) {seq_3<-c((seq_3[1]):
(seq_3[length(seq_3)]+1))}}
}
}
My concern is that it gets stuck in an infinite loop because it has been running for 7 days now for 1700 trips (in total 2000 hr GPS data).
beginner algorithm time-limit-exceeded r
beginner algorithm time-limit-exceeded r
edited 30 mins ago
Jamal♦
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 30 mins ago
Jamal♦
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 30 mins ago
Jamal♦
30.3k11116226
edited 30 mins ago
Jamal♦
30.3k11116226
edited 30 mins ago
Jamal♦
30.3k11116226
30.3k11116226
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
asked 9 hours ago
Elmira BerjisianElmira Berjisian
1
1
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Elmira Berjisian is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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