Get the row in a CSV where xyz coordinates stop changing - r

Question

I have a measurement of an object with xyz coordinates and a timeline in ms. My CSV looks like this:
TimeInSec X.6 Y.6 Z.6
0.000000 -1.383422 -0.058891 0.023290
0.004167 -1.387636 -0.058947 0.023584
0.008333 -1.391491 -0.058972 0.023989
...
I want to find the row in my dataset where the xyz coordinates stop changing (within a threshold). The key feature I want is a time from row 0 to the stop point of my object.
My Code:
dummy.data <- read.csv (file="D:\\tmp\\dummy.csv", header = TRUE, skip = 6
dummy.data %>%
gather(key,value, X.6, X.7, X.8, Y.6, Y.7, Y.8, Z.6, Z.7, Z.8) %>%
ggplot(aes(x=Time..Seconds., y=value, colour=key)) +
geom_line()
Many Thanks for your help!
Sample Graph:
Sample Graph
Here is the link to the RawData CSV RawData

Answer 1

Here's an updated example that uses exactly the same code as before but now I made some dummy data that shows different offsets and the data settles to a constant value eventually. The point is that successive points will get closer and closer so a Euclidean distance (think of this as the actual distance) between successive points will get smaller. Once below the threshold, we declare the points to have settled.
library(tidyverse)
library(ggplot2)
numberofpoints <- 100
threshold <- 0.01
set.seed(1)
dummy.data <- # make some dummy data with offsets
data.frame(
X.6=runif(numberofpoints), X.7=runif(numberofpoints), X.8=runif(numberofpoints),
Y.6=runif(numberofpoints), Y.7=runif(numberofpoints), Y.8=runif(numberofpoints),
Z.6=runif(numberofpoints), Z.7=runif(numberofpoints), Z.8=runif(numberofpoints)) %>%
mutate(
X.6=3+X.6/row_number(), X.7=1+X.7/row_number(), X.8=2+X.8/row_number(),
Y.6=4+Y.6/row_number(), Y.7=6+Y.7/row_number(), Y.8=9+Y.8/row_number(),
Z.6=5+Z.6/row_number(), Z.7=7+Z.7/row_number(), Z.8=10+Z.8/row_number()
)
distances <- dist(dummy.data) # find distances between all pairs of readings (will be slow for large data)
distances.matrix <- as.matrix(distances)
# distances between adjacent readings
distancechange <- c(NA,unlist(sapply(1:numberofpoints-1, function(r) distances.matrix[r,r+1])))
# the first point below the threshold
changebelowthreshold <- min(which(distancechange < threshold))
# Plot something
dummy.data$Time <- 1:nrow(dummy.data)
thresholdtime <- dummy.data$Time[changebelowthreshold]
plotdata <- dummy.data %>% pivot_longer(cols=c(X.6, X.7, X.8, Y.6, Y.7, Y.8, Z.6, Z.7, Z.8))
gg <- ggplot(plotdata, aes(x=Time, y=value, colour=name)) + geom_line() + geom_vline(xintercept = thresholdtime)
This makes the following plot.
The vertical line shows where the data is below a threshold.

Answer 2

I think from your description you just want to identify a point where the differences between x, y and z values in consecutive rows drop below a certain threshold:
threshold <- 0.001
stop_row <- which(abs(diff(dummy.data$X.6)) < threshold &
abs(diff(dummy.data$Y.6)) < threshold &
abs(diff(dummy.data$Z.6)) < threshold )
So now you can do:
result <- dummy.data$TimeInSec[stop_row] - dummy.data$TimeInSec[1]