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Tomasz,
thank You for the new beta, again great improvements!
Just a tip: You forgot to change the headline in Change Log section of the Read Me.
You wrote:
CHANGES FOR VERSION 4.34.2 (as compared to 4.34.0)
instead of
CHANGES FOR VERSION 4.35.0 (as compared to 4.34.2)
Stephan
--- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <tj@xxxx> wrote:
>
> Hello,
>
> A new beta version (4.35.0) of AmiBroker has just been released.
>
> It is available for registered users only from the members area at:
> http://www.amibroker.com/members/bin/ab4350beta.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
>
> Short list of changes in this beta (read change log in the "read me" below for the details):
>
> a.. do-while loop implemeted
> b.. it is now allowed to 'add' (or rather concatenate) string to a number / array. This saves quite a bit of typing.
> c.. additional tweaks in AFL engine & garbage collection, futher speed up of execution of very long loops
> d.. more error checking in AFL engine - will report using uninitialized variables that were accepted silently in 4.31.x - 4.34.x
> e.. standard include paths for #includes
> f.. IIf/Min/Max are now overloaded functions (have two variants each)
> g.. added 'endless loop detection threshold' setting to Preferences "AFL" tab. Recommended value 100000 or higher.
> h.. fixed parameter counting in CallFunction plugin callback in case of overloaded functions
> i.. fixed problem with premature freeing of arrays passed in default parameters fields (causing for example problem with color exploration output - introduced in 4.32)
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
>
> AmiBroker 4.35.0 Beta Read Me
> May 8, 2003 17:01
>
> 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 4.35.0 beta" written in the About box.
>
> See CHANGE LOG below for detailed list of changes.
>
> 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)
>
> do-while Statement
>
> The do-while statement lets you repeat a statement or compound statement until a specified expression becomes false.
>
> Syntax
>
> do statement while ( expression ) ;
>
> The expression in a do-while statement is evaluated after the body of the loop is executed. Therefore, the body of the loop is always executed at least once.
>
> The expression must have numeric or boolean type. Execution proceeds as follows:
>
> 1.. The statement body is executed.
>
>
> 2.. Next, expression is evaluated. If expression is false, the do-while statement terminates and control passes to the next statement in the program. If expression is true (nonzero), the process is repeated, beginning with step 1.
> This is an example of the do-while statement:
>
> x=100;
> do
> {
> y = sin( x );
> x--;
> } while ( x > 0 );
> In this do-while statement, the two statements y = sin( x ); and x--; are executed, regardless of the initial value of x. Then x > 0 is evaluated. If x is greater than 0, the statement body is executed again and x > 0 is reevaluated. The statement body is executed repeatedly as long as x remains greater than 0. Execution of the do-while statement terminates when x becomes 0 or negative. The body of the loop is executed at least once.
>
>
> 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:
> a.. 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.
>
>
> b.. 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 averageif, 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 4.34.2 (as compared to 4.34.0)
>
> a.. do-while loop implemented:
> Syntax:
>
> do statement while ( expression ) ;
>
> The expression in a do-while statement is evaluated after the body of the loop is executed.
> Therefore, the body of the loop is always executed at least once.
>
> Example:
>
> i=0;
> do
> {
> i++;
> }
> while( i < 100 );
> WriteVal( i );
>
>
> b.. it is now allowed to 'add' (or rather concatenate) string to a number / array. This saves quite a bit of typing. This works as in JScript. The left-hand operand of '+' has to be a string. The right-hand operand may be string, number or array. Numbers are coerced to strings using %g sprintf formatting (prints out decimal point only when necessary) and then concatenated. In case of arrays SELECTED VALUE is coerced to string and then concatenated.
>
> So now instead of
>
> i = 100;
> "Value is " + WriteVal( i );
> "Close : " + WriteVal( Close ) + ", Open : " + WriteVal( Open ) + ", High : " + WriteVal( High );
>
> you can write:
>
> i = 100;
> "Value is " + i;
> "Close : " + Close + ", Open : " + Open + ", High : " + High;
>
> Note that
>
> "Test " + 100 + 1;
>
> will give you "Test 1001" because statements are parsed from left to right.
> "Test " is added first to "100" giving "Test 100" and then to "1" giving
> "Test 1001". If you want to perform numeric adding first please use braces:
>
> "Test " + ( 100 + 1 );
> - this will give you "Test 101"
>
>
> c.. additional tweaks in AFL engine & garbage collection, futher speed up of execution of very long loops
>
> d.. more error checking in AFL engine - will report using uninitialized variables that were accepted silently in 4.31.x - 4.34.x
> e.. #include now accepts new way of specifying file names to include:
>
> #include <filename.afl>
>
> (note < > braces instead of " " ) if you specify the file name this way AmiBroker will look for
> the file in "standard include path" that is definable using new prefs setting in Tools->Preferences->AFL
> It makes much shorter to write includes and you can move include folder now without changing all AFL codes using #includes.
>
> For example if you have set standard include path to "C:\AFL\MyIncludes" and write in your formula:
>
> #include <common.afl>
>
> AmiBroker will look for C:\AFL\MyIncludes\common.afl file
>
> Also now #include reports file(s) not found in regular error message box.
>
>
> f.. IIf/Min/Max are now overloaded functions (have two variants each)
> IIF( Condition_ARRAY, True_Array, False_Array ) (old one)
> IIF( BoolValue, TrueValue, FalseValue )
>
> Min( array1, array2 ) (old one)
> Min( number1, number2 )
>
> Max( array1, array2 ) (old one)
> Max( number1, number2 )
>
> The second one is choosen when all arguments are numbers and it is much much faster and returns number so LastValue() call is not neccessary anymore.
>
> Example:
>
> // much faster and does not require LastValue()
> period = IIF( name() == "MSFT", 5, 10 );
> result = Min( 7, 3 );
> // (result is still a number not array as in previous versions)
>
>
> g.. added 'endless loop detection threshold' setting to Preferences "AFL" tab. Recommended value 100000 or higher.
>
> h.. fixed parameter counting in CallFunction plugin callback in case of overloaded functions
> i.. fixed problem with premature freeing of arrays passed in default parameters fields (causing for example problem with color exploration output - introduced in 4.32)
>
> CHANGES FOR VERSION 4.34.2 (as compared to 4.34.0)
>
> a.. improved crash recovery dialog to include AFL engine state information and (in some cases) the source line of the formula that causes an exception
> b.. added ability to catch all exceptions in indicators and commentaries (switchabel via Tools->Preferences->AFL, "catch system exceptions...", ON by default) - allows you to continue to work even in case of serious problem
> c.. loop break by Shift+BREAK is now more sensitive
> d.. now you can control how often Shift+BREAK key is checked during formula execution (Tools->Preferences->AFL, "check SHIFT+Break every" (1..100, default = 50) (note that specifying low values may degrade performance slightly)
> e.. tweaked AFL memory allocator hash tables to get more speed for large looping formulas
> f.. although I never reproduced this problem I made some changes so 'TAB' key should not wipe the contents of AFL editor anymore
> CHANGES FOR VERSION 4.34.0 (as compared to 4.33.0)
>
> a.. user-definable functions and procedures with parameters and local variables
>
> b.. '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.
>
> c.. indicator list column width increased in Indicator Builder
> d.. 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)
>
> a.. 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)
>
>
> b.. 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.
>
>
> c.. 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 );
>
> d.. fixed sometimes incorrect output of variable-period version of LLV/HHV
>
> e.. 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)
>
> a.. second bug in experimental garbage collector fixed.
> CHANGES FOR VERSION 4.32.1 (as compared to 4.32.0)
>
> a.. garbage collector was releasing memory too soon in some cases, now fixed.
> CHANGES FOR VERSION 4.32.0 (as compared to 4.31.1)
>
> a.. added type check in IF/ELSE statements
> b.. added type check in array element assignment
> c.. error messages now numbered and display changed slightly
> d.. you can break running loop by pressing Shift+BREAK (Pause) key combination
> e.. calling COM objects works again (was broken in 4.31.x)
> f.. changed slightly the way TAB works in editor, if TAB is pressed any selection is deselected to avoid accidential deletion of text
> g.. 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.
> h.. new tab in preferences for AFL engine settings
> i.. 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)
>
> a.. 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)
>
> a.. Workspace window uses "icon font" set in the Windows settings instead of hard coded Tahoma 8
> b.. 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.
> c.. 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.
> d.. 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;
>
> e.. 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;
> }
>
> f.. implemented C-style postfix and prefix increment/decrement operators
>
> i = 10;
> WriteIf( i++ );
> WriteIf( ++i );
> WriteIf( i );
>
> g.. 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 ];
> }
>
>
>
> h.. 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
>
> i.. implemented infinite-loop protection. Nice if you forgot to increment counter variable in 'for' loop :-)
>
> j.. tab key now works without need to press ALT/CTRL in AFL editors
>
> k.. 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@xxxx
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