# R/trigonometric.moment.R In circular: Circular Statistics

#### Documented in trigonometric.moment

```#############################################################
#                                                           #
#       Original Splus: Ulric Lund                          #
#       E-mail: ulund@calpoly.edu                           #
#                                                           #
#############################################################

#############################################################
#                                                           #
#   trigonometric.moment function                           #
#   Author: Claudio Agostinelli                             #
#   Email: claudio@unive.it                                 #
#   Date: August, 10, 2006                                  #
#   Copyright (C) 2006 Claudio Agostinelli                  #
#                                                           #
#   Version 0.3-3                                           #
#############################################################

trigonometric.moment <- function(x, p = 1, center = FALSE, control.circular=list()) {
x <- unlist(x)
if (is.circular(x)) {
datacircularp <- circularp(x)
} else {
datacircularp <- list(type="angles", units="radians", template="none", modulo="asis", zero=0, rotation="counter")
}
dc <- control.circular
if (is.null(dc\$type))
dc\$type <- datacircularp\$type
if (is.null(dc\$units))
dc\$units <- datacircularp\$units
if (is.null(dc\$template))
dc\$template <- datacircularp\$template
if (is.null(dc\$modulo))
dc\$modulo <- datacircularp\$modulo
if (is.null(dc\$zero))
dc\$zero <- datacircularp\$zero
if (is.null(dc\$rotation))
dc\$rotation <- datacircularp\$rotation

# Handling missing values
x <- na.omit(x)
if ((n <- length(x))==0) {
warning("No observations (at least after removing missing values)")
return(NULL)
}
x <- conversion.circular(x, units="radians", zero=0, rotation="counter")
attr(x, "class") <- attr(x, "circularp") <-  NULL

mu.p <- conversion.circular(circular(res[1]), dc\$units, dc\$type, dc\$template, dc\$modulo, dc\$zero, dc\$rotation)
result <- list(mu=mu.p, rho=res[2], cos=res[3], sin=res[4], p=res[5], n=res[6], call=match.call())
return(result)
}

TrigonometricMomentRad <- function(x, p, center) {
center <- as.numeric(center)
n <- length(x)
sinr <- sum(sin(x))
cosr <- sum(cos(x))
circmean <- atan2(sinr, cosr)
sin.p <- sum(sin(p * (x - circmean * center)))/n
cos.p <- sum(cos(p * (x - circmean * center)))/n
mu.p <- atan2(sin.p, cos.p)
rho.p <- sqrt(sin.p^2 + cos.p^2)
result <- c(mu.p, rho.p, cos.p, sin.p, p, n)
return(result)
}
```

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circular documentation built on April 27, 2022, 1:06 a.m.