X = trend(X,range)
X [ tseries ] - Input time series.
Range [ tseries ] - Range for which the trend will be computed.
X [ tseries ] - Output trend time series.'break=' [ numeric | empty ] - Vector of breaking points at which the trend may change its slope.
'connect=' [ true | false ] - Calculate the trend by connecting the first and the last observations.
'diff=' [ true | false ] - Estimate the trend on differenced data.
'log=' [ true | false ] - Logarithmise the input data, de-logarithmise the output data.
'season=' [ true | false | 2 | 4 | 6 | 12 ] - Include deterministic seasonal factors in the trend.