Example: Fractal Indicator

Nikolay.Gekht · #1 (**permalink**) 10-12-2009, 01:51 PM

Here is a source code for the Bill Williams 5-bar Fractal oscillator as it is described at Fractals — Technical Indicators, Technical Analysis

1) Create the file fractal.lua
2) Copy the code below into this file
3) Save the file
or
1,2,3) Just right-click on this link and choose "Save As..." from the menu.

4) Go to "Charts/Chart/Manage Custom Indicators" menu of the Trading Station
5) Click "Load"
6) Choose the fractal.lua file created at the previous steps

Unfortunately, the current version of the Marketscope does not support the labels, so, the fractals
are specified as the red (up) or green (down) bars in the oscillator area.

Code:

function Init()
    indicator:name("Fractal");
    indicator:description("Bill Williams Fractal oscillator")
    indicator:requiredSource(core.Bar);
    indicator:type(core.Oscillator);

    indicator.parameters:addColor("UpC", "Color of the up fractal", "", core.rgb(255, 0, 0));
    indicator.parameters:addColor("DownC", "Color of the down fractal", "", core.rgb(0, 255, 0));
end

local source;
local up, down;

function Prepare()
    source = instance.source;
    local name = profile:id();
    instance:name(name);
    up = instance:addStream("Up", core.Bar, name .. ".Up", "Up", instance.parameters.UpC, 4, -2);
    up:addLevel(1);
    up:addLevel(0);
    up:addLevel(-1);
    down = instance:addStream("Down", core.Bar, name .. ".Down", "Down", instance.parameters.DownC, 4, -2);
end

function Update(period, mode)
    if (period > 6) then
        local curr = source.high[period - 2];
        if (curr > source.high[period - 4] and curr > source.high[period - 3] and
            curr > source.high[period - 1] and curr > source.high[period]) then
            up[period - 2] = 1;
        else
            up[period - 2] = nil;
        end
        curr = source.low[period - 2];
        if (curr < source.low[period - 4] and curr < source.low[period - 3] and
            curr < source.low[period - 1] and curr < source.low[period]) then
            down[period - 2] = -1;
        else
            down[period - 2] = nil;
        end
    end
end

ak_nomiss · #2 (**permalink**) 11-14-2009, 07:58 AM

anyway can you change this to indicator so it can show like the regular fractors ? there is no way we can use this indicator and find out where are the fractors stand

Nikolay.Gekht · #3 (**permalink**) 11-16-2009, 12:46 PM

Unfortunately, the current version of the marketscope does not allow to show labels using indicator. I'll think how can we do this using existing capabilities...

The fractors usually stands at the chosen candle high or low, so the question is how to detect the candle fast. I can only suggest to use the crosshair cursor which is drawn through prices and all indicators.