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Tomasz,
chapeau! AmiBroker is now the Ferrari of TA software. Thrills the driver!
Franco
Tomasz Janeczko wrote:
>
> Hello,
>
> A new beta version (4.34.0) of AmiBroker has just been released.
>
> It is available for registered users only from the members area at:
> http://www.amibroker.com/members/bin/ab4340beta.exe
>
> If you forgot your user name / password to the members area
> you can use automatic reminder service at:
> http://www.amibroker.com/login.html
>
> The highlight of this release are user definable functions / procedures
> allowing passing parameters and supporting local variables.
>
> Please read "HELP ON NEW FEATURES" section below for the details.
> The description of remaining additions is included in the CHANGE LOG
> later in this document.
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
>
>
>
> *AmiBroker 4.34.0 Beta Read Me*
>
> April 30, 2003 13:42
>
> *_THIS IS AN EARLY BETA VERSION OF THE SOFTWARE. EXPECT BUGS !!!_*
>
> *AGAIN: _THIS IS AN EARLY BETA VERSION OF THE SOFTWARE. EXPECT BUGS !!!_**_
> _*
>
> *Backup your data files and entire AmiBroker folder first!*
>
> *INSTALLATION INSTRUCTIONS*
>
> _*IMPORTANT: This archive is update-only. You have to install full
> version 4.30 first.*_
>
> Just run the installer and follow the instructions.
>
> Then run AmiBroker. You should see "AmiBroker 4.34.0 beta" written in
> the About box.
>
>
> *HELP ON NEW FEATURES*
>
> *USER-DEFINABLE FUNCTIONS, PROCEDURES, LOCAL/GLOBAL VARIABLES (4.34 or
> higher)*
>
> Here is a sample code showing user-defined function:
>
> |// the following function is 2nd order smoother|
>
> |function IIR2( input, f0, f1, f2 )
> {
> result[ 0 ] = input[ 0 ];
> result[ 1 ] = input[ 1 ]; |
>
> | for( i = 2; i < BarCount; i++ )
> {
> result[ i ] = f0 * input[ i ] +
> f1 * result[ i - 1 ] +
> f2 * result[ i - 2 ];
> }|
>
> | return result;
> }|
>
> |Plot( Close, "Price", colorBlack, styleCandle );
> Plot( IIR2( Close, 0.2, 1.4, -0.6 ), "function example", colorRed ); |
>
>
> In this code *IIR2* is a user-defined function. *input, f0, f1, f2* are
> formal parameters of the functions.
> At the time of function call the values of arguments are passed in these
> variables. Formal parameters behave like local variables.
> Later we have *result* and *i* which are local variables. Local
> variables are visible inside function only. If any other function uses
> the same variable name they won't interfere between each other.
>
> Due to the fact that AFL does not require to declare variables the
> decision whenever given variable is treated as local or global is taken
> depending on where it is FIRST USED.
>
> If given identifier appears first INSIDE function definition - then it
> is treated as LOCAL variable.
> If given identifier appears first OUTSIDE function definition - then it
> is treated as GLOBAL variable.
>
> Example (commentary):
>
> |k = 4; // this is GLOBAL variable|
>
> |function f( x )
> {
> z = 3; // this is LOCAL variable|
> | return z * x * k; // 'k' here references global variable k (first
> used above outside function)
> ||}|
>
> |z = 5; // this is GLOBAL variable with the same name as local variable
> in function f|
>
> |"The value of z before function call :" + WriteVal( z );|
>
> |// Now even if we call function
> // the value of our global variable z
> // is not affected by function call because
> // global variable z and local variable z are separate and
> // arguments are passed by value (not by reference)|
>
> |"The result of f( z ) = " + WriteVal( f( z ) );|
>
> |"The value of z after function call is unchanged : " + WriteVal( z );|
>
> At the end of the function we can see 'return' statement that is used to
> return the result to the caller. Note that currently return statement
> must be placed at the very end of the function.
>
> It is also possible to write a procedure (a function that returns
> nothing (void))
>
> |procedure SinePlotter( Freq, ColorIndex )
> {
> pname = "Line"+WriteVal(ColorIndex,1.0);
> array = sin( Cum( Freq * 0.01 ) );
> Plot( array, pname , colorRed + ColorIndex, styleThick );
> }|
>
> |for( n = 1; n < 10; n++ )
> {
> SinePlotter( n/2+Cum(0.01), n );
> }|
>
> Note that although there are two separate keywords 'function' and
> 'procedure' AmiBroker currently treats them the same (they both accept
> return values but not require them), but in the future the rules maight
> get enforced to use
> return statement ONLY in conjunction with function keyword. So it is
> advised to use function keyword in case when your function returns any
> value and procedure keyword otherwise.
>
> Note also that recursion (having a function call itself from within
> itself) is NOT supported as for now.
>
> *FLOW CONTROL AND LOOPING (4.31 or higher)*
>
>
> while Statement
>
> The while statement lets you repeat a statement until a specified
> expression becomes false.
>
> *Syntax*
>
> *while (* /expression/ *)* /statement/
>
> The /expression/ must have arithmetic (numeric/boolean) type. Execution
> proceeds as follows:
>
> 1. The /expression/ is evaluated.
>
> 2. If /expression/ is initially false, the body of the *while*
> statement is never executed, and control passes from the *while*
> statement to the next statement in the program.
>
> If /expression/ is true (nonzero), the body of the statement is
> executed and the process is repeated beginning at step 1.
>
> This is an example of the *while* statement:
>
> |i = 10;
> while( i < 20 )
> {
> Plot( MA( Close, i ), "MA" + WriteVal( i, 0 ), colorBlack + i );
> i = i + 1;
> }|
>
> The example plots 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 - bar moving
> averages.
>
>
>
>
> for Statement
>
> **
>
> The *for* statement lets you repeat a statement or compound statement a
> specified number of times. The body of a *for* statement is executed
> zero or more times until an optional condition becomes false.
>
> *Syntax*
>
> *for (* /init-expression/ *;* /cond-expression/ *;* /loop-expression/
> *)* /statement/
>
> Execution of a *for* statement proceeds as follows:
>
> 1. The /init-expression/, is evaluated. This specifies the
> initialization for the loop. There is no restriction on the type
> of /init-expression/.
>
> 2. The /cond-expression/, is evaluated. This expression must have
> arithmetic type. It is evaluated before each iteration. Three
> results are possible:
> * If /cond-expression/ is true (nonzero), /statement/ is
> executed; then /loop-expression/, if any, is evaluated. The
> /loop-expression/ is evaluated after each iteration. There
> is no restriction on its type. Side effects will execute in
> order. The process then begins again with the evaluation of
> /cond-expression/.
>
> * If /cond-expression/ is false (0), execution of the *for*
> statement terminates and control passes to the next
> statement in the program.
>
> This example illustrates the *for* statement:
>
> |
> |
>
> |myema[ 0 ] = Close[ 0 ];|
>
> |for( i = 1; i < BarCount; i++ )
> {
> myema[ i ] = 0.1 * Close[ i ] + 0.9 * myema[ i - 1 ];
> }|
>
> ||
>
> |||This example iterates all bars of close array to calculate exponential moving average|||
>
>
> if, else Statements
>
> *if(* /expression /*)*
> /statement1/
> [*else*
> /statement2/]
>
> The *if* keyword executes /statement1/ if /expression/ is true
> (nonzero); if *else* is present and /expression/ is false (zero), it
> executes /statement2/. After executing /statement1/ or /statement2/,
> control passes to the next statement.
>
> *Example 1*
>
> |if ( i > 0 )
> y = x / i;
> else
> {
> x = i;
> y = abs( x );
> }|
>
> In this example, the statement |y = x/i;| is executed if |i| is greater
> than 0. If |i| is less than or equal to 0, |i| is assigned to |x| and
> abs|( x )| is assigned to |y|. Note that the statement forming the *if*
> clause ends with a semicolon.
>
> When nesting *if* statements and *else* clauses, use braces to group the
> statements and clauses into compound statements that clarify your
> intent. If no braces are present, the compiler resolves ambiguities by
> associating each *else* with the closest *if* that lacks an *else*.
>
> *Example 2*
>
> |if ( i > 0 ) /* Without braces */
> if ( j > i )
> x = j;
> else
> x = i;|
>
> The *else* clause is associated with the inner *if* statement in this
> example. If |i| is less than or equal to 0, no value is assigned to |x|.
>
> *Example 3*
>
> |if ( i > 0 )
> { /* With braces */
> if ( j > i )
> x = j;
> }
> else
> x = i;|
>
> The braces surrounding the inner *if* statement in this example make the
> *else* clause part of the outer *if* statement. If |i| is less than or
> equal to 0, |i| is assigned to |x|.
>
>
> CHANGE LOG
>
> *CHANGES FOR VERSION 4.34.0 (as compared to 4.33.0)*
>
> * user-definable functions and procedures with parameters and local
> variables
> * 'A' is NO LONGER predefined symbol. I decided to remove it because
> people tend to use A as user-variable forgetting the fact that it
> was build-in array holding typical price (H+L+C)/3. *Use 'Avg'
> instead.*
> * indicator list column width increased in Indicator Builder
> * DayOfYear - returns the calendar day number counting from
> beginning of the year January 1st is 1. Maximum number returned is
> 366
>
> *CHANGES FOR VERSION 4.33.0 (as compared to 4.32.2)*
>
> * Database purify tool implemented (available via Tools->Database
> Purify)
> allows to detect missing/extra quotes, possible splits, invalid
> OHLC relationship
>
> Apply to/range settings similar to AA window. You can also right
> click over result list to add symbols to watch list and copy the
> list to the clipboard (and paste it later to any other program for
> futher use)
>
> * further improvements to AFL garbage collector, now looping
> regardless of loop count requires the same amount of memory as
> just single pass of the code (no growing allocated memory during
> loops).
> This enormously lowered memory consumption for some formulas and
> increased the speed of some loops 3..4 times.
>
> * added variable period support to the following functions:
> LinRegSlope,
> LinearReg,
> LinRegIntercept,
> StdErr,
> TSF
>
> Sample code:
>
> Plot( Close, "Test", colorBlack );
>
> range = 15 * MA( ATR( 15 ), 50 ) / ATR( 15 );
>
> //Plot( range, "range", colorBlue, styleOwnScale );
> Plot( LinearReg( Close, range ), "Test", colorRed );
>
> *
>
> fixed sometimes incorrect output of variable-period version of LLV/HHV
>
> *
>
> fixed crash occuring when bad arguments were passed to the
> function (bug introduced in 4.32.x).
>
> *CHANGES FOR VERSION 4.32.2 (as compared to 4.32.1)*
>
> * second bug in experimental garbage collector fixed.
>
> *CHANGES FOR VERSION 4.32.1 (as compared to 4.32.0)*
>
> * garbage collector was releasing memory too soon in some cases, now
> fixed.
>
> *CHANGES FOR VERSION 4.32.0 (as compared to 4.31.1)*
>
> * added type check in IF/ELSE statements
> * added type check in array element assignment
> * error messages now numbered and display changed slightly
> * you can break running loop by pressing Shift+BREAK (Pause) key
> combination
> * calling COM objects works again (was broken in 4.31.x)
> * changed slightly the way TAB works in editor, if TAB is pressed
> any selection is deselected to avoid accidential deletion of text
> * /experimental:/ added 'agressive garbage collector' that extremely
> decreases the amount
> of memory required to run AFL formula by releasing the memory
> used for temporary variables as soon as possible (previously
> temporary memory was released at the end of formula execution).
> A side-effect of new garbage collector is some speed up in formula
> execution.
> * new tab in preferences for AFL engine settings
> * /experimental feature, NOT for beginners, may be removed/modified
> in future releases/:
> new _TRACE( "string" ) AFL function added
> that allows to write debug messages from AFL code to system debug
> viewer.
> (it calls internally OutputDebugString Win API function).
> To view debug messages you have to run DebugView freeware program
> from http://www.sysinternals.com/
>
> *CHANGES FOR VERSION 4.31.1 (as compared to 4.31.0)*
>
> * fixed bug introduced in 4.31.0 causing no text output in
> commentary/interpretation**
>
> *CHANGES FOR VERSION 4.31.0 (as compared to 4.30.0)*
>
> * Workspace window uses "icon font" set in the Windows settings
> instead of hard coded Tahoma 8
> * for better readability and ClearType(tm) compatibility on WinXP,
> all dialog windows use now 'MS Shell Dlg' face name that maps to
> standard MS Sans Serif on Win 9x/Me/NT and Tahoma on Win 2K and XP.
> * rewritten AFL parser, now formula is parsed and coverted to syntax
> tree and then interpreted. This would allow further improvements
> including compilation. This allowed also to add loops/if-else
> statements.
> * implemented IF/ELSE statement, WHILE and FOR loops:
> The same basic 'for' loop in AFL is 2..3 times faster than in JScript
> Syntax follows C++/JScript style:
>
> /while( conditional_expression ) statement;/
>
> /for( initializer_part; conditional_expression; iterator_part )
> statement;/
>
> /if( conditional_expression ) statement;/
>
> /if( conditional_expression )
> statement;
> else
> statement;/
>
> *
>
> implemented compound statements: these are blocks of statements
> enclosed
> in opening and closing curly brace
>
> /{
> statement1;
> statement2;
> ...
> statementN;
> }/
>
> compound statement can appear anywhere when simple statement can.
>
> For example:
>
> |i = 10;
> while( i < 20 )
> {
> Plot( MA( Close, i ), "MA" + WriteVal( i, 0 ), colorBlack + i );
> i = i + 1;
> }|
>
> *
>
> implemented C-style postfix and prefix increment/decrement operators
>
> |i = 10;
> WriteIf( i++ );
> WriteIf( ++i );
> WriteIf( i );|
>
> *
>
> implemented array element access (subscript) operator []:
>
> |WriteVal( Close[ 0 ] ); // prints the first bar of close array|
>
> |/* a sample low-level implementation of exponential moving
> average in AFL */|
>
> |myema[ 0 ] = Close[ 0 ];|
>
> |for( i = 1; i < BarCount; i++ )
> {
> myema[ i ] = 0.1 * Close[ i ] + 0.9 * myema[ i - 1 ];
> }|
>
> *
>
> added built-in constant 'BarCount' that returns number of bars
> available in arrays (the number of elements of array)
> When QuickAFL is turned on it may be less than true number of bars
> because QuickAFL feature attempts to use only visible bars (and
> few before). You can control how many bars the formula requires
> using SetBarsRequired() function
>
> *
>
> implemented infinite-loop protection. Nice if you forgot to
> increment counter variable in 'for' loop :-)
>
> *
>
> tab key now works without need to press ALT/CTRL in AFL editors
>
> *
>
> added C-like synonyms for logical ADD/OR/NOT: &&, ||, !
>
>
> |/* a sample low-level implementation of Profit-target stop in
> AFL: */|
>
> |Buy = Cross( MACD(), Signal() );|
>
> |priceatbuy=0;|
>
> |for( i = 0; i < BarCount; i++ )
> {
> if( priceatbuy == 0 && Buy[ i ] )
> priceatbuy = BuyPrice[ i ];|
>
> | if( priceatbuy > 0 && SellPrice[ i ] > 1.1 * priceatbuy )
> {
> Sell[ i ] = 1;
> SellPrice[ i ] = 1.1 * priceatbuy;
> priceatbuy = 0;
> }
> else
> Sell[ i ] = 0;
> }|
>
> |/* sample EMA rainbow */|
>
> |Plot( Close, "Price", colorBlack, styleCandle );
> for( Range = 15; Range < 100; Range++ )
> Plot( EMA( Close, Range ), "MA"+WriteVal(Range,0), colorRose +
> Range % 8, styleNoLabel );|
>
> *HOW TO REPORT BUGS*
>
> If you experience any problem with this beta version please send
> detailed description of the problem (especially the steps needed to
> reproduce it) to bugs@xxxxxxxxxxxxx <mailto:bugs@xxxxxxxxxxxxx>
>
>
> *Yahoo! Groups Sponsor*
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>
>
>
> Send BUG REPORTS to bugs@xxxxxxxxxxxxx
> Send SUGGESTIONS to suggest@xxxxxxxxxxxxx
> -----------------------------------------
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