Loading Additional Data for Accumulative Calculations

Historical calculations for RadarScreen (Quotes) indicators are performed by loading only the minimum number of bars required. Accumulation or smoothing type indicators such as the "Mov Avg Exponential" indicator use accumulative calculations. Accumulative calculations begin with an initial value and then calculate subsequent values based on prior values. For example, a running sum that is calculated on each bar by adding 1 to the sum's value on the prior bar would be an accumulative (and starting-point dependent) calculation. Unless you load additional bars of data, the values for these indicators may differ in RadarScreen from those for the same indicator in Chart Analysis.

To ensure that the values of these indicators are consistent between RadarScreen and Chart Analysis, you must load additional bars of data. To do this, you need to enable the Load additional data for accumulative calculations option on the Customize Indicator - General tab. You can then specify the number of additional bars to load so RadarScreen will perform the necessary accumulative calculations. The values for these indicators will then match those in Chart Analysis.

  This option is only intended for grid-based studies using accumulative calculations. Chart-based studies and those that do not use accumulative calculations will not be affected by enabling this option. There is no benefit in loading additional data for indicators that do not accumulate variable values. Doing so will only add demand additional memory and processor overhead from your computer. By default, the Load additional data for accumulative calculations option is disabled for new studies and is pre-set for any TradeStation supplied studies that require it.

The number of additional bars needed is a factor of three variables: price, volatility, and input values. Following is a list of the indicator calculations that require a smoothing factor and the input factor for determining the approximate number of additional bars needed for indicator values to match what is used in Chart Analysis. Use the input value and multiply that by the smoothing factor below to get the appropriate value to enter in the Additional bars to load box. For example, if you are calculating the ADX indicator with the calculation length set to 20 then, taking the 12 from the table below and the Length input's setting of 20, set the "Additional bars to load" to 240 (12 x 20) or more. You may have to experiment with the value to ensure that the value that appears in RadarScreen matches the value shown in a chart of the same symbol and same bar interval.

Indicator Calculations	Input	Smoothing Factor
ADX	Length	12
ADX Classic	Length	6.5
ADXR	Length	12
Average True Range	Length	4
Com Selection Index	Length	8.5
DMI	Length	12
MACD Slow	Length	6
McClellan Oscillator Slow	Length	2
Mass Index	NA	130
Moving Average Exponential	Length	4.5
RSI	Length	9.5
Stochastic Fast	Length	2.5
Stochastic Slow	Length	3.5
TRIX	Length	10.5
Volatility	Length	7.5