LM trend log functions Back

---

require('trends')

Include library before calling trend log functions

---

trends.fetch(name, dates, resolution)
trends.fetchone(name, dates, resolution)

Fetch one or many values for the given period

Parameters:

• name trend log name, required
• dates Lua table with two items - 'start' and 'end', each item must contain 'year', 'month', 'day' keys, time values (hours, minutes and seconds) are ignored, required
• resolution optional, will use trend resolution if not specified, set to 86400 for retreive daily data

Return values:

fetch returns Lua table with values for the given period or nil on error. Number of values depends on period, resolution and data retention settings

fetchone returns single value for the given period or nil on error

Example:

require('trends')

-- will fetch data between 2016.04.15 00:00 and 2016.04.16 00:00
dates = {
  ['start'] = { year = 2016, month = 4, day = 15 },
  ['end'] = { year = 2016, month = 4, day = 16 },
}

-- fetch current value
day = trends.fetchone('Gas', dates)

-- get data for the past year
dates = {}
dates['start'] = os.date('*t')
dates['start'].year = dates['start'].year - 1
dates['end'] = os.date('*t')

-- fetch previous value
yearly = trends.fetch('Gas', dates, 86400)

---

trends.NaN value is used for points which contain invalid values or cannot be found

The default value is 0, but it can also be set to 0 / 0 (NaN - not a number).

Example:

require('trends')

-- use "not a number" for invalid values
trends.NaN = 0 / 0

-- get data for the past year
dates = {}
dates['start'] = os.date('*t')
dates['start'].year = dates['start'].year - 1
dates['end'] = os.date('*t')

value = trends.fetchone('Hot Water', dates)

-- NaN ~= NaN, means value was not found
if value ~= value then
  return
end