Value Oscillator (Variable Length) [OscVL]

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The Value Oscillator (Variable Length) function calculates the difference between two variable length moving averages for a field, returning the difference as a raw value or percentage. This function differs from the other Value Oscillators only in the type of moving average that it uses. Parameters ------------------ Data               The data to use in the calculation. This is typically a field in a data series or a calculated value. Short Period   The number of bars of data to include in the shorter average, including the current value.                        For example, a period of 3 includes the current value and the two previous values. Long Period   The number of bars of data to include in the longer average, including the current value.                        For example, a period of 7 includes the current value and the six previous values. Maximum Period   The maximum value that Period can contain.                              Larger values require extra memory to be set aside for this function to be calculated. As Percent     A boolean value indicating whether to return the difference as a raw value or as a percentage.                        A value of zero indicates to return the actual difference in value.                        Any other value (non-zero) indicates to return the difference as a percentage. Function Value ------------------------ The Value Oscillator is calculated by subtracting the value of a longer term moving average from the value of a shorter term moving average. If it is expressed as a percentage, the value is relative to the shorter moving average and is traditionally multiplied by 100 for easier graphing. To make it relative to the longer period, reverse the order of the short and long periods and negate the result. The Value Oscillator at the beginning of a data series is not defined until there are enough values to fill the longer period. If the period is greater than the maximum period or negative, the value is not defined. If the period contains a fractional number, only the integer portion will be used. There are inherent problems if the Short Period becomes longer than the Long Period. Usage ----------- The Value Oscillator can be used for analyzing both price data and volume data. When analyzing price data, it can be used to detect price trends. Specifically, when the shorter term moving average decreases below the longer term moving average, prices have been trending lower. When this function is used in entry/exit systems, signals are typically generated when the value crosses zero or specific thresholds. Trading when a value oscillator crosses zero is functionally the same as trading when the shorter moving average crosses the longer moving average. See the sample entry/exit systems for examples of moving average crossing systems. When analyzing volume data, it can used to detect trends in market sentiment. For example, when the shorter term moving average decreases below the longer term moving average, overall volume is decreasing, indicating reduced interest in the current trend.