怀尔德开发的一系列流行的指标包括RSI,ATR,DMI等指标都在他1978年出版的《技术交易系统新概念》一书中有所简介。使用者应该意识到的是，怀尔德并没有使用标准的EMA公式。认识到这一点对于你如何设置指标周期有很大影响。
怀尔德移动平均线的计算公式
标准EMA计算公式把时间周期转换成分数，公式为EMA% = 2/(n + 1)。其中，n代表时间。比如，14日的EMA%=2/(14 日+1) = 13.3%. 然而，怀尔德使用1/14 也就是 7.1%作为EMA%的值。这就等于使用标准公式计算出的27日EMA。
怀尔德指标
受到影响的指标有
• 真实波幅指标ATR;
• 定向移动指标DMI;
• 相对强弱指标RSI;
• 资金流向指标MFI — 由 Colin Twiggs 利用怀尔德的MA计算公式开发。
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指标的时间框架
当使用上述指标时，我们建议使用者使用较小的时间框架。比如，如果你交易30日周期，那么你通常需要选择15日指标周期。对于RSI周期的选择，你可以根据以下公式：
RSI 周期 = (n + 1) / 2 = (15 + 1) / 2 = 8 日
Wilder Moving Average
A number of popular indicators, including Relative Strength Index (RSI), Average True Range (ATR) and Directional Movement were developed by J. Welles Wilder and introduced in his 1978 book: New Concepts in Technical Trading Systems. Users should beware that Wilder does not use the standard exponential moving average formula. This can have significant imapct when selecting suitable time periods for his indicators.
Welles Wilder's Moving Average Formula
The standard exponential moving average formula converts the time period to a fraction using the formula EMA% = 2/(n + 1) where n is the number of days. For example, the EMA% for 14 days is 2/(14 days +1) = 13.3%. Wilder, however, uses an EMA% of 1/14 which equals 7.1%. This equates to a 27-day exponential moving average using the standard formula.
Welles Wilder's Indicators
Indicators affected are:
• Average True Range;
• Directional Movement System;
• Relative Strength Index; and
• Twiggs Money Flow — developed by Colin Twiggs using Wilder's moving average formula.
Indicator Time Frames
We recommend that users try shorter time periods when using one of the above indicators. For example, if you are tracking a 30-day cycle you would normally select a 15-day Indicator Time Period. With the RSI, adjust the time period as follows:
RSI time period = (n + 1) / 2 = (15 + 1) / 2 = 8 days
本文翻译由兄弟财经提供
文章来源：http://www.incrediblecharts.com/indicators/wilder_moving_average.php