# R/curve.angle.R In SenguptaLab/MF.matR: Takes mirofluidics data and does stuff with it

#### Documented in curve.angle

```#' function to calculate 3 point curvature based on law of cosines
#' function is intended to be used with default arguments within a Wormlab data structure
#' @param del.x1 change from previous point (t-1) to (t0)
#' @param del.y1 change from previous point (t-1) to (t0)
#' @param del.x2 change from t(-2) to t(-1)
#' @param del.y2 change from t(-2) to t(-1)
#' @export
#' @examples
#' WL.alldata %>% mutate(curve.ang = as.numeric(mapply(MF.matR::curve.angle, del.x1, del.y1, del.x2, del.y2))*180/pi))
curve.angle <- function(del.x1, del.y1, del.x2, del.y2) {
values <- list(del.x1, del.y1, del.x2, del.y2)
if(anyNA(values)) {
"NA"
} else {
x <- c(del.x1, del.y1)
y <- c(del.x2, del.y2)
dot.prod <- x%*%y
norm.x <- as.numeric(svd(x)[1]) # faster to use svd and index (which for 1x1 vec is all norm does)
#norm(x,type="2") # length of vector
norm.y <- as.numeric(svd(y)[1])
#norm(y,type="2")
theta <- acos(dot.prod / (norm.x * norm.y))
as.numeric(theta)
}
}
```
SenguptaLab/MF.matR documentation built on March 25, 2020, 4:30 p.m.