Building an Expert Advisor to draw and manage a Fibonacci retracement
The Fibonacci Trader Plug-in can programatically draw a trend line on a price chart using the fnDrawFibo function.
To build an Expert Advisor that opens a BUY trade when a programatically drawn Fibonacci retracement level has been broken, refer to the drawing below:
- Notice the two links coming from the Start Element. You can number any link by double-clicking it. The link number defines the order of execution.
- Following Link #1:
- The Function Element "fnIsNewBar1" gets a true value if a new bar has just been formed. If this EA is attached to a 1-hour price chart, a new bar will be formed at the beginning of each hour.
- The Logic Element "IsNewBar" compares the value of "fnIsNewBar1" to true.
- If the "IsNewBar" Logic evaluates to true, then the Function "fnDeleteFibo1" deletes the Fibonacci retracement, and the Function "fnDrawFibo" draws a new Fibonacci retracement.
- Note: The Fibonacci retracements are identified by their name (e.g. "MyFib")
- Following Link #2:
- The Function Element "fnIsFibLevelBroken" get a true value if the specified level has been broken, from the specified direction.
- The Logic Element "IsLineBroken" compares the value of "fnIsFibLevelBroken" to true.
- If the "fnIsFibLevelBroken" Logic evaluates to true, then the function "fnOpenOrder1" opens a trade.
- Note: The variable MaxTrades will prevent multiple trades from being opened if "fnOpenOrder1" executes more than once.
Four coordinates are required to draw a line in two dimensional space. For example, on a typical graph, using the Cartesion coordinate system, the coordinates are usually defined as (x1, y1) and (x2,y2).
The primary coordinates of the trend line are defined as the StartBar, the StartPrice, the EndBar and the EndPrice.
- StartBar: set the value of the StartBar parameter to the bar (or candle) where the trend line should begin.
- NOTE: On a MetaTrader price chart, the currently forming candle is defined as candle 0 and the candle numbers increase to the left. Therefore, the StartBar is a larger number than the EndBar!
- StartPrice: set the value of the StartPrice parameter to a price value constant. The price is the vertical location where the line begins. The StartPrice is the price value of the StartBar.
- StartOffset: set the value of the StartOffset parameter to a positive or negative integer value (for example:10, 20, ...). The StartOffset value moves the vertical start location up or down relative to the StartPrice.
- EndBar: set the value of the EndBar parameter to the bar (or candle) where the trend line should end.
- NOTE: A trend line is projected to the right indefinitely regardless of where the EndBar is located. The EndBar simply defines the angle of the line, not its actual end point.
- EndPrice: set the value of the EndPrice parameter to a price value constant. The price is the vertical location where the trend line ends. The EndPrice is the price value of the EndPrice.
- NOTE: If the EndPrice is set as the Close, High, or Low of bar number 0, or to Ask or Bid, then the EndPrice may change value on each tick.
- EndOffset: set the value of the EndOffset parameter to a positive or negative integer value (for example:10, 20, ...). The EndOffset value moves the vertical end location up or down relative to the EndOffset.
- LineColor: optionally set the value of the LineColor parameter to a Color. The default is Black.
- DrawLabel: optionally set the value of the DrawLabel parameter to a true. (The default is false.) This will draw a label with the name of the trend line on the price chart. The label can be removed programatically using fnDeleteAllLabels, or manually from from the MetaTrader tool bar.
- DrawMarks: optionally set the value of the DrawMarks parameter to a true. (The default is false.) This will draw a vertical lines through the start and end bars. The vertical lines can be removed programatically using fnDeleteAllVerticalLines, or manually from from the MetaTrader tool bar.
