# R/which_simple.R In spatial.tools: R Functions for Working with Spatial Data

#### Documented in which.max.simplewhich.min.simple

```#' Location of Maximum Value
#'
#' Locates the largest value of the input object.
#'
#'
#' @param x a numeric object
#' @param na.rm a logical indicating whether missing values should be removed.
#' @param tie_value A character indicating how to deal with ties.  Can be "NA"
#' (returns an NA if a tie is found) or "random" (returns a single randomly
#' chosen member of the ties if a tie is found) or "first" (returns the first
#' class found).
#' @return An integer of length 1 giving the index of the maximum of x or NA if
#' the maximum of x is not unique, x has no non-NAs, or na.rm=F.
#' @author Jonathan A. Greenberg, Alison R. Mynsberge
#' @keywords calculate
#' @examples \dontrun{
#'
#' x<-c(2:4,1,1,NA)
#' y<-c(4,1:3,NA,4)
#' ## The index is only calculated for a unique maximum
#' which.max.simple(x)
#' which.max.simple(y)
#' which.max.simple(y,na.rm=FALSE)
#' which.max.simple(x,na.rm=FALSE)
#' }
which.max.simple=function(x,na.rm=TRUE,tie_value="NA")
{
if(na.rm)
{
x=x[!is.na(x)]
}
if(length(x)==0)
{
return(NA)
}
maxval=max(x)
if(is.na(maxval))
{
return(NA)
}
if(sum(x %in% maxval) > 1)
{
# Ties exist, figure out what to do with them.
if(tie_value=="NA")
{
return(NA)
}

if(tie_value=="random")
{
tie_postions=which(x==maxval)
return(sample(tie_postions,size=1))
}

if(tie_value=="first")
{
tie_postions=which(x==maxval)
return(tie_postions[1])
}

} else
{
return(which.max(x))
}
}

#' Location of Minimum Value
#'
#' Locates the smallest value of the input object.
#'
#'
#' @param x a numeric object
#' @param na.rm a logical indicating whether missing values should be removed.
#' @param tie_value A character indicating how to deal with ties.  Can be "NA"
#' (returns an NA if a tie is found) or "random" (returns a single randomly
#' chosen member of the ties if a tie is found) or "first" (returns the first
#' class found).
#' @return An integer of length 1 giving the index of the minimum of x or NA if
#' the minimum of x is not unique, x has no non-NAs, or na.rm=F.
#' @author Jonathan A. Greenberg, Alison R. Mynsberge
#' @keywords calculate
#' @examples \dontrun{
#'
#' x<-c(4,1:3,NA,4)
#' y<-c(2:4,1,1,NA)
#' ## The index is only calculated for a unique minimum
#' which.min.simple(x)
#' which.min.simple(y)
#' which.min.simple(y,na.rm=FALSE)
#' which.min.simple(x,na.rm=FALSE)
#' }
which.min.simple=function(x,na.rm=TRUE,tie_value="NA")
{
if(na.rm)
{
x=x[!is.na(x)]
}
if(length(x)==0)
{
return(NA)
}
minval=min(x)
if(is.na(minval))
{
return(NA)
}
if(sum(x %in% minval) > 1)
{
# Ties exist, figure out what to do with them.
if(tie_value=="NA")
{
return(NA)
}

if(tie_value=="random")
{
tie_postions=which(x==minval)
return(sample(tie_postions,size=1))
}

if(tie_value=="first")
{
tie_postions=which(x==minval)
return(tie_postions[1])
}

} else
{
return(which.min(x))
}
}
```

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spatial.tools documentation built on April 23, 2018, 3 a.m.