Mfunctions: Various Helpful R Functions

#' @title Create Binaries
#' @description Creates the Binary output of a number
#' @param i numeric; numeric to be transformed in a binaric array
#' @param bit numeric; number of digits for the binaric ountput
#' @export

binary <- function(i,bit){

  if((2^bit)<i){stop("The number is too large to be represented by the amount of digits")}
  bite<-bit-1
  a<-2^(0:bite)
  b<-2*a

  # Revert by Sum from 7 to 0 (7:0) -> Starting with Day 1 to 8 (MODIS codes from Day 8 to Day 1)
  u<-sapply(i,function(x) sum(10^(0:bite)[(x %% b)>=a]))
  res<-sprintf(paste0("%0",bit,"d"),u)
  return(res)
}

#' @title Calculate Sum of Digits
#' @description Computes the sum of digits in one number
#' @param x numeric; any numeric
#' @export

digitsum <- function(x) sum(floor(x / 10^(0:(8 - 1))) %% 10)


#' @title Multiple grepl operations
#' @description Allows to add multiple patterns to a grepl operation.
#' These multiple patterns are then tested against other strings.
#' This function is based on the base grepl operator
#' @param mypatterns string(s); list of multiple input strings
#' @param x string(s); list of multiple target patterns
#' @export

multigrepl      <- function(mypatterns,x){

  # Initialize the For iteration for processing the relevant patterns
  # The x has to stay the same
  for(i in 1:length(mypatterns)){

    g1<-grepl(mypatterns[i],x)
    if(i==1){g2<-g1}
    g2[which(g1==T)]=TRUE

  }
  return(g2)
}

#' @title Start at NA location
#' @description Checks the first NA value within a matrix or array and returns
#' the location. Useful function for iteratively filling an object without
#' the use of another iteration
#' @param myinp empty array or matrix; This object must be empty or just created
#' filled with NA.
#' @export

startfun        <- function(myinp) {
  if(class(myinp)=="matrix"){start<-min(which(is.na(myinp[,1])));return(start)}
  if(class(myinp)=="array"){start<-min(which(is.na(myinp)));return(start)}
}