Check For Closest Number

I was wondering if there is a way to compare multiple numbers to see which is closest to a target number. If there is not a single command if someone can point me in the direction of something that would work. Or if nothing of this sort exists that i will just have to come up with something creative to solve this problem.

There is no already implemented solution. As such you would need to create something… But first things first, how would you deal 2 or 3 numbers being the same distance apart? Assume we have this

num = 3
other = 1, 2, 2, 2, 3

What would be the closest? 2 or 2,2,2?

Now assume we also have the following

num = 3
other = 1, 2, 4

What would be the closest? 2 or 4?

And lastly

num = 3
other = 1, 2, 3, 4, 5

What would be the closest? 3?

theoriginalbit, on 01 September 2013 - 03:37 PM said:

There is no already implemented solution. As such you would need to create something… But first things first, how would you deal 2 or 3 numbers being the same distance apart? Assume we have this

num = 3
other = 1, 2, 2, 2, 3

What would be the closest? 2 or 2,2,2?
all 3 of them

Now assume we also have the following

num = 3
other = 1, 2, 4

What would be the closest? 2 or 4?
2 and 4 would be closest for what i am trying to do

And lastly

num = 3
other = 1, 2, 3, 4, 5

What would be the closest? 3?

3 would be closest

The way i am doing this shortly described below deals with numbers much higher than those, and there will be very little repetition or 2 numbers being the same distance from the target.

What i am attempting to make is error checking function for my better edit program. The way i am doing this is using the string.byte built in api then gathering the top 5 or so results with the closest being on the top, if 2 are equal distance then it will just be the first one that occurs in the table that it is comparing to. There is probably a better way to do what i am trying to do but i feel as if i should write my own code and figure it out for myself if i am making it for my program.

Thx for the response i highly doubted the something like that existed

Yeh you're definitely going to have to write your own. Make a function, that accepts varargs

local function someName(...)
  --# code here
end

Varargs can be accessed via the predefined table `args` or by making it yourself via `{…}`

then just loop through this table, and return the closest value (keeping in mind the rules you just stated above to my quote).

theoriginalbit, on 01 September 2013 - 04:03 PM said:

Yeh you're definitely going to have to write your own. Make a function, that accepts varargs

local function someName(...)
  --# code here
end

Varargs can be accessed via the predefined table `args` or by making it yourself via `{…}`

then just loop through this table, and return the closest value (keeping in mind the rules you just stated above to my quote).

I just thought of this, I have not tested it and do not even know if it will work. Whatever i post here will almost 100% not be the final product.

starting = {
"124",
"15",
}
target = 90
temp = 0
temp2 = 0
function findDistance() -- finds distance from target
  for i = 1, #starting do
	if starting[i] > target then
	  while starting~= target do
		temp = temp+1
		starting = starting-1
		temp2 = temp2+1
	  end
	elseif starting[i] < target then
	  while starting ~= target do
		temp = temp+1
		starting = starting+1
		temp2=temp2+1
	elseif starting[i] == target then
	  temp = 0
	  temp2=temp2+1
	end
	table.insert(distance,temp2,temp)
  end
end

This is only partially finished but that will find the distance from the target number I am probably going to use the table.sort command to be able to see which is closest. In order to use the sort function i will have to use ALOT of comparing in a inefficient way. None of that code above has been tested and probably does have errors.

This after editing has ALOT of errors i have fixed them and this part of the code works exactly as wanted

I am writing a code for this right now.
I will edit this post when done!

Here is my version:

number = 32
others = {1, 432, 30, 432, 234, 65, 42, 76, 73}

function findClosest(num, other)
	if(type(other) == "number")then
		return other;
	end
	closest = other[1]
	closeamount = num - closest
	for id, tar in pairs(other) do
		if(num - tar < closeamount)then
			if(num - tar > 0)then
				closest = tar
				closeamount = num - tar
			else
				check = (num - tar) * -1
				if(check < closeamount)then
					closest = tar
					closeamount = check
				end
			end
		end
	end
	return closest 
end

print(findClosest(number, others))

Here, this is my idea (sorry if there are typos, i'm on my mobile):

local function getNearest(target, list)
  local tempLNearest, tempRNearest = 0,1000000
  for k,v in pairs(list) do
    if v > tempLNearest and v <= target then
      tempLNearest = v
    elseif v < tempRNearest and v >= target then
      tempRNearest = v
    end
  end
  return tempLNearest,tempRNearest
end

--Example usage
local list = {1,3,5,7,9,11,13}
local target = 6
term.clear()
print("LIST")
print(table.concat(list,","))
print("")
print("TARGET")
print(target)
print("")
print("FOUND")
local n1,n2 = getNearest(target,list)
print(n1,",",n2)

Ok since Freack posted a solution, I may as well post one too. So here it is.

local function getClosest(target, ...)
  --# temp variable which will store the number and its distance from the target
  local info = {}
  --# loop through the numbers supplied
  for _,v in ipairs(arg) do
	--# insert it into the table with the distance it is from the target, in whole positive numbers
	table.insert(info, {v, math.abs(target-v)})
  end
  --# sort the table, based on the distances from the target
  table.sort(info, function(a,B)/>/> return a[2] < b[2] end)
  --# create a new table for the return values
  local ret = {}
  --# loop through the newly sorted info table
  for i,v in ipairs(info) do
	--# put the value into the ret table in the same order it was in the sorted table
	ret[i] = v[1]
  end
  --# unpack the table into the return results
  return unpack(ret)
end

And it would be used like so

--# get just the one closest number
local c1 = getClosest(5, -10, 15, -5, -1, -2, 11, -3, 10, 15, 30)

--# get 3 of the closest numbers
local c1, c2, c3 = getClosest(5, -10, 15, -5, -1, -2, 11, -3, 10, 15, 30)

--# get all the numbers in order based on the distance
local order = { getClosest(5, -10, 15, -5, -1, -2, 11, -3, 10, 15, 30) }