--[[
========================================
SUBTRACT VALUES
========================================
PURPOSE:
  Subtracts a constant value from each input.
FORMULA:
  output = input - SUB_VALUE
EXAMPLE:
  SUB_VALUE = 5
  Input: 50 → Output: 45
USER ACTION:
  Modify SUB_VALUE in USER EDIT SECTION
========================================
]]
function SubtractValue(input)
    if input == nil then return {} end
    local output = {}
    -------------------------------------------------
    -- USER EDIT SECTION
    -------------------------------------------------
    local SUB_VALUE = 5   -- Value to subtract
    -------------------------------------------------
    for tag = 1, 10 do
        local key = tostring(tag)
        local inVec = input[key]
        if type(inVec) == "table" then
            local outVec = {}
            for i, v in ipairs(inVec) do
                local val = (v.value or 0) - SUB_VALUE
                table.insert(outVec, {
                    value = val,
                    quality = v.quality or 0,
                    timestamp = v.timestamp or 0
                })
            end
            output[key] = outVec
        end
    end
    return output
end