Navigation: Realtest Script Language > Syntax Element Details > MDI Category Indicator Functions Description Wilder's Minus Directional Index Syntax MDI(len) Parameters len - lookback period Notes This is the negative component of the ADX indicator, often referred to as -DI. This indicator supports one-pass calculation when used in the Data Section with a non-variable length. Example MinusDI: MDI(14) PlusDI: PDI(14) Typically used together with PDI to determine directional trend. Copyright © 2020-2026 Systematic Solutions, LLC