Users' Knowledge Base

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/*P_ForeignRGB*/ 
 
Color = ParamColor("Color",colorCustom2);
//Color = ParamColor("Color",ColorRGB(204,0,204));
 
Plot(C,"Close",Color,styleLine|styleThick);
 
PlotForeign("GM","GM",colorCustom2, styleLine|styleThick);
//PlotForeign("GM","GM",ColorRGB(204,0,204), styleLine|styleThick);

(Note that for this example the style has been changed to a thick line, by adding styleThick to the code, to make it easier to see the color of the plots in a screenshot).



Any one of the 40 colors in the Color-Picker, or the 16 color favorites can be set as the ParamColor default. This can be extended to the full range of colors available in the 24 bit palette i.e. 255 * 255 * 255, which is approximately equal to 16 million colors, by the use of color functions within formulas.

To do this it is necessary to obtain the Red Green Blue numerical code for the color of choice.

To record the Color Matrix numerical code for an extended color:

a) open the ParamColor extended Color Palette (refer to the Users’ Knowledge Base Article ’Custom Colors - Extending The Range’ for instructions),
b) create the color of choice by maneuvering the pointer, either on the Luminescence Bar or within the Color Matrix and make a note of the numerical code for the chosen color e.g. Red 204, Green 0, Blue 204.




c) click on OK and the Properties window will open with the custom color settings displayed e.g. RGB (204,0,204).



The plot color, for the current symbol will change to reflect the parameter setting.



The plot color can be set to use any color in the extended palette as the default.
There are two ways to do this; first by replacing color with a ColorFunction within the standard plot (or plotForeign code) or alternatively by using a ColorFunction within ParamColor arguments.

To change the foreign plot to an extended color:

a) comment out line 8 in the formula and uncomment line 9,
b) type the Red Green Blue (RGB) numerical code into the ColorRGB function arguments exactly as they were written in the Properties box (refer to the example text highlighted in yellow),
c) Save the formula to enact the changes.



To change the current (parametrical) plot to use an extended color as the default (and demonstrate the functionality):

a) comment out line 3,
b) uncomment line 4,
c) Save the formula and then close the Formula Editor,
d) close the lower chart pane by clicking on the cross that appears when the mouse is hovered over the top right hand corner,



e) right click on P_Foreign in the Charts list and then Insert it (this will install a new chart in the lower pane with RGB(204,0,204) as the default color, along with the option of changing the color settings via the Palette Editor, in case you have changed your mind about the color in the few seconds it took to insert the formula).

With the following three lines of code the result in the chart below was produced.

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Color = ParamColor("Color",ColorRGB(204,0,204));
Plot(C,"Close",Color,styleLine|styleThick); 
PlotForeign("GM","GM",ColorRGB(204,0,204), styleLine|styleThick);

Notice that the colors are identical.

The good news is, that if you have changed your mind about the current color, you still have the choice of 56 colors in the Picker, or the rest of the 16 million colors in the extended palette up your sleeve.

And now for a little fun let’s type 255, 255, 255 into the Color Matrix and see what we get.



No sense in doing things by half. Let’s try 000.




Finally the ’piece de resistance’.

Try the following code by Tomasz Janeczko (from the AFL Function Reference; ColorHSB examples).

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// Example 1: 
// 3-d multicolor multiple moving average cloud chart 
side = 1;
increment = Param("Increment",2, 1, 10, 1 );
for( i = 10; i < 80; i = i + increment ) 
{ 
up = MA( C, i );
down = MA( C, i + increment ); 
 
if( ParamToggle("3D effect?", "No|Yes" ) ) 
side = IIf(up<=down AND Ref( up<=down, 1 ), 1, 0.6 ); 
 
PlotOHLC( up,up,down,down, "MA"+i, ColorHSB( 3*(i - 10),
Param("Saturation", 128, 0, 255 ), 
side * Param("Brightness", 255, 0, 255 ) ), styleCloud | styleNoLabel );
}

Filed by brian_z at 5:12 am under Using Custom Colors
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(3 votes, average: 4 out of 5)

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/*P_Foreign*/ 
 
//Color = ParamColor("Color",colorRed); 
//Plot(C,"Close",Color,styleLine); 
 
Plot(C,"Close",colorBlack,styleLine);
PlotForeign("GM","GM",colorCustom2, styleLine);

To apply the formula as a dynamic indicator chart:

a) save the code as P_Foreign,
b) right click on it and select Edit from the context menu (the Formula Editor window will open),
c) click on Apply from the Formula Editor Standard Toolbar. (The indicator will open in a new dynamic pane, however, the dynamics will only hold for the initial instance, while the Formula Editor remains open ).



(Note that for this example the DJIA example database installed with AmiBroker has been used. AA, the first stock symbol in that database, is the current chart, and GM has been chosen as the foreign symbol, because, at the time of writing it’s price was close to that of AA. This provides a more compact view in the chart. Readers who are following this tutorial can substitute any other symbols as required).

The ParamColor function then needs to be added to the formula, to add a graphical Color-Picker interface to the chart.

To add color parameters to the current symbol:

a) uncomment line 3 (this assigns the ParamColor function output to the variable Color),
b) uncomment line 5 (this substitutes the ’contents’ of the variable Color, for the reserved variable colorBlack, in the standard plot code),
c) comment out the standard plot code in line7 (it has been replaced by line 5),
c) Save the formula to apply the new settings.



The plot color for AA is now the default color of the ParamColor function i.e. colorRed. This can be changed to a custom color, that is not available in the color favorites group, from within the Properties window.

To apply an extended custom color to the current plot:

a) right click in the chart,
b) select Parameters from the context menu (the Properties window will open with the Parameters [tabbed] page in view),
c) use the dropdown on that page to open the Color-Picker,



d) click on More at the bottom of the Color-Picker table (the Palette Editor opens),
e) check the second box on the top row of Custom colors (for this example only Custom color box two will be set),
f) then pick a Basic color (the check marks on Custom color box2 will not be retained but it is still the active box),
g) click on the desired base color variation in the Luminescence bar, or, click/hold and drag the arrow head for fine control,
h) in addition, or alternatively, click on the desired color variation in the Color Matrix, or click/hold and drag the moving pointer for fine control, (to allow for ease of replication, this example was created using option ’g’ alone).



i) when the desired color is displayed in the Color/Solid box select Add to Custom Colors > OK. (The new color will be applied to the Parameters color setting and appear in the chart).



Notice that the foreign plot is still referencing colorCustom2 (Black), from the favorites collection, while the current symbol color is referencing the color selected from the extended range. (The extended Palette Editor does not overwrite the favorites collection!).



When using extended custom colors, it is not necessary to set them in the Custom colors table, as per the example, unless two or more will be used and interchanged in the one session. (If that is the case Custom colors can be set, to allow for an easy return to the same color, but they will not be available in a new session). The method used was chosen purely to demonstrate the differences between color favorites and extended custom colors . The easiest way to set extended colors, for one off use, is simply to click OK once the desired color has been produced by manipulating the matrix pointer.

While the Custom color settings are not retained between sessions any preferred Parameter color settings are e.g. the current view will be reinstated after closing and reopening AmiBroker. (In the installed version the current chart is automatically saved, as the default, at the end of the session).

The current view can also be saved for recycling, as a template, so that it will not be overwritten if the default is changed.

To save the current view as a template:

a) right click in the chart and select Template > Save from the available options, (the Save As window will open),



b) Name the file and Save it. (The current data folder is the default view in the installed version. Thereafter it will change to the last folder used in this window).



The saved template operates globally, as well as with the local database, so, if it is going to be used with other databases it is more convenient to save it in a generic Templates folder.

To create a Template folder and save a template file (continuing from step ’a’ above):

a) click on the Up One Level icon to access the AmiBroker folder list,



b) create a new folder under AmiBroker, (a New Folder will appear with the name highlighted in blue),



c) hit the Delete key to clear the text and rename the folder by typing Templates into the folder text box,
d) open the Templates folder, after naming it, and save the template file there as P_Foreign.



The template, complete with the parameter color settings, can be reinstated anytime, and for any database. (In this case the database would need to contain the symbol used in the formula.).

To open the saved template:

(As preparation for this example, and to demonstrate the functionality of templates, the chart window was closed and AmiBroker was shutdown. After reopening AmiBroker a New > Blank Chart was installed from the File menu. In normal use it is not necessary to do this as the template will overwrite any chart when it is opened).

a) right click in the chart window where the template is to be installed,



b) browse the file list and open P_Foreign.ALY that is in the Templates folder,



P_Foreign will open using the first symbol in the All symbols list. (This example was created using the DJIA example database installed with AmiBroker. ^DJI is the first symbol in that database, so, in the example it is the current symbol).

c) select AA from the All symbols list to restore the view to the saved version.

Additional foreign plots can be added to the chart, each with their own customized color.

To add additional customized plots:

a) copy/paste line 3 & 8 into the Formula Editor page, as line 10 & 12 respectively, then edit them as shown to add Color2 as a Parameter option, (after saving, dual options will become available in the Properties window),

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/*P_Foreign*/
 
Color = ParamColor("Color",colorRed);
 
Plot(C,"Close",Color,styleLine);
 
//Plot(C,"Close",colorBlack,styleLine);
PlotForeign("GM","GM",colorCustom2, styleLine);
 
Color2 = ParamColor("Color2",colorRed);
 
PlotForeign("DIS","DIS",Color2, styleLine);

b) use the Color-Picker to set Color2.




All three plots will now be displayed with their own colors. (The first and third symbols are using unique colors that are not included in the Color-Picker or color favorites).

Filed by brian_z at 12:40 am under Using Custom Colors
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(2 votes, average: 4 out of 5)

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Filed by brian_z at 8:48 am under Using Custom Colors
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(1 votes, average: 2 out of 5)

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/*P_PriceFields*/
 
Plot(C,"Close",colorBlack,styleLine);
//Plot(C,"Close",colorBlack);
//Plot(C,"Close",colorRed);
//color = ParamColor("color",colorRed); 
//Plot(C,"Close",color);

b) copy/paste or type line 3 of the code into a new Formula Editor page,
c) check the syntax using the Verify Syntax tool from the Formula Editor Standard Toolbar before saving it as P_PriceFields,

• p_pricefields.afl (188 bytes)

Filed by brian_z at 1:45 pm under Using Custom Colors
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(2 votes, average: 3 out of 5)

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Filed by brian_z at 3:46 am under Using Custom Colors
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(1 votes, average: 2 out of 5)

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To count the number of trading days in a calendar year (for any equity market):

a) download the .afl file attached to this post and save it in Program Files/AmiBroker/Formulas/Custom,

b) open AmiBroker and display any index, for the market of interest, in a chart e.g. ^DJI;
c) find p-barsinyear in the Charts list and right click on it, then Insert it as an indicator, (it will be plotted in a new pane in the bottom section of the Chart window);
d) click in the Chart to position the Selector Line in the BarsInYear chart, just after the end of the year being measured (where the cumulative line becomes a constant in the upper section of the chart);
e) read the BarsInYear total from the Chart Title (highlighted in yellow).

(Note that this calculation requires daily bars and also that it is set to calculate the number of trading days for the last full year at the time of writing i.e. 2006. To calculate the number of trading days for a different year e.g. 2007, change the 106 to 107 in both of the DateNum() number sequences).

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/*P_BarsInYear*/
 
InYearFlag = IIf(DateNum() >= 1060101 AND DateNum() <= 1061231,1,0);
InYear = Cum(InYearFlag);
Plot(InYear,"BarsInYear",colorBlack,styleLine);
 
// Logic.
// line 3 returns one if a bar is within the calendar range, or zero if not, and assigns it to the variable InYearFlag;
// line 4 cumulates the ones from line 3 and assigns the result to the InYear variable;
// line 5 plots the cumulated result in a chart;

Attached Files:

• p-barsinyear.afl (424 bytes)

_{Right click and Save Target As to save .afl files to the desktop at Program Files/AmiBroker/Formulas/Custom and access them as formulas within AmiBroker Charts.}

Filed by brian_z at 9:15 am under AFL - Utilities and Functions
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Look-ahead problems occur when, during Backtesting, your code uses future prices to calculate signals. When this happens, your system’s performance may be heavily inflated, but obviously since you are looking into the future, the system cannot be traded.

While the Indicator formula editor menu has a Check function, it often fails when debugging complex systems, especially if they use Plug-Ins or DLLs. Also, when it discovers a problem, it does not show you at which bar the problem occurred. The simple code presented here detects all look-ahead problems that might occur during a Backtest, even if your system uses Plugins or DLLs, and it can be appended to any system.

The code makes use of the fact that setting a future bar to NULL will cause dependent variables and signals to change. To use this technique your Arrows must be placed using the PlotShapes() function so that they will change when you NULL future bars. This would not happen if the arrows are placed by the Backtester. Thus, you should turn Off Arrows in your Param() menu.

To test for Look-Ahead problems, you should copy the code to your system formula and Apply it to an Indicator pane. Make sure your chart is fully right justified so that you can see the last bar, and zoom so that you can see some signal arrows. Next, open the Param window and move the slider to change the Remove Bars count. As you do this you will see bars disappearing, last bar first. When the disappearance of a bar causes a preceding arrow to disappear, your system looks ahead.

Note that this code can also be used to detect Indicator dependence on future bars. If your indicator changes ahead of your NULL bar, your Indicator is dependent on future data. When changes are very small, this may be hard to see. It would be an interesting coding challenge to save a number of bars and compare so that even small changes can be detected. Perhaps someone will write a DLL to do all this for us.

A minor drawback of this code is that you have to scan your chart manually, which may take a few minutes. You could add an automated scan and run the code using an exploration, generating an error table for an entire Watchlist. It wouldn’t be very fast, but it would increase the chance of detecting all possible errors.

The demo code below uses the Zig() function to place signals and arrows on the chart. Since Zig() looks ahead by varying amounts, it is perfect to demonstrate how this code works.

EnableNulling = ParamToggle("NULLing of Data","DISABLED|ENABLED",0);
RM = Param("NULL Bars L<-R",0,0,1000,1);
if( EnableNulling )
{
Z = Null;
LB = LastValue(BarIndex());
O = IIf(BarIndex()>(LB-RM),Z,O);
H = IIf(BarIndex()>(LB-RM),Z,H);
L = IIf(BarIndex()>(LB-RM),Z,L);
C = IIf(BarIndex()>(LB-RM),Z,C);
}
ZChange = Param("%Zig",0.1,0,1,0.05);
Z = Zig(C,ZChange);
Buy = Z < Ref(Z,1) AND Z < Ref(Z,-1);
Sell = Z > Ref(Z,1) AND Z > Ref(Z,-1);
Short = Sell;
Cover = Buy;
Plot(C,"",1,128);
PlotShapes(IIf(Buy, shapeSmallUpTriangle, shapeNone),5,0,BuyPrice,0);
PlotShapes(IIf(Sell, shapeHollowDownTriangle, shapeNone),4,0,SellPrice,0);
PlotShapes(IIf(Cover, shapeHollowUpTriangle, shapeNone),5,0,CoverPrice,0);
PlotShapes(IIf(Short, shapeSmallDownTriangle, shapeNone),4,0,ShortPrice,0);

Edited by Al Venosa

Filed by Herman at 2:53 am under Debugging AFL
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(2 votes, average: 5 out of 5)

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