celltrackR (version 1.2.1)

angleSteps: Angle between Two Steps

Description

Compute the angle between two steps in the dataset that occur at the same timepoint.

Usage

angleSteps(X, trackids, t, degrees = TRUE, quietly = FALSE)

Value

A single angle, or NA if the desired step is missing for one or both of the tracks. If trackids is a matrix with multiple step pairs to compute angles for, the output is a numeric vector of angles (or NA values).

Arguments

X

a tracks object

trackids

a vector of two indices specifying the tracks to get steps from, or a dataframe/matrix of two columns (where every row contains a pair of trackids to compute a step angle for)

t

the timepoint at which the steps should start, or a vector of timepoints if trackids is a matrix with multiple step pairs to compute angles for.

degrees

logical; should angle be returned in degrees instead of radians? (defaults to TRUE)

quietly

logical; should a warning be returned if one or both of the steps are missing in the data and the function returns NA?

See Also

distanceSteps to compute the distance between the step starting points, timePoints to list all timepoints in a dataset, and AngleAnalysis for other methods to compute angles and distances.

Examples

## Find the angle between the steps of the tracks with ids 1 and 2, at the 3rd
## timepoint in the dataset.
t <- timePoints( TCells )[3]
angleSteps( TCells, c("1","3"), t )

## Do this for multiple pairs and times at once: between cells 1 and 3 at the
## 3rd timepoint, and between 1 and 4 at the fourth timepoint.
pairs <- data.frame( cell1 = c("1","1"), cell2 = c("3","4"))
times <- timePoints(TCells)[3:4]
angleSteps( TCells, pairs, times )