Fibonacci Levels and EMAs

TradingView Pine Script error explanation – “The 'undeclared identifier' error happens when TradingView cannot find the variable or function that we try to use.”​
TRADINGCODE.NET
Pine Script scope and assignment solution – Define variables in global scope and use := inside if blocks​
STACKOVERFLOW.COM
. This prevents “undeclared identifier” errors for variables set in conditional logic.
Pine Script plotting rules – “You can't use plot statements in ... any other local block in a script.” (must be global)​
TOUCH-DT.COM
.
Example of invalid plot parameter causing error – using an unsupported 'dashed' style in plot() led to an undeclared identifier issue​
REDDIT.COM
. Always use valid plot styles or drawing functions for custom line styles.
Fibonacci level calculation example – computing fib retracement levels from a high and low price​
TRADINGVIEW.COM
(standard 23.6%, 38.2%, 50%, 61.8% formula).