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Thank you again for a remarkable product, Tomasz.
Best regards,
Bill
--- In amibroker@xxxxxxxxxxxxxxx, "Tomasz Janeczko" <amibroker@xxxx>
wrote:
> Hello,
>
> A new beta version (4.39.0) of AmiBroker has just been released.
>
> It is available for registered users only from the members area at:
> http://www.amibroker.com/members/bin/ab4390beta.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
>
> List of changes in this beta (read change log in the "read me"
below for the details)
>
> a.. added Param dialog to AA window. Note that AA-defined
parameters are reset back to defaults only when you LOAD the formula
from the file or when you click on 'Reset' button in Parameter
dialog.
>
> a.. colorAqua now has correct value of 36
>
> a.. when Printing charts (or using Print Preview ) in Real Time
mode,
> auto-refresh is temporarily disabled to avoid problems with printing
>
> a.. fixed problem with non-updating last bar of trade arrays by
Equity(1)
> applied in exploration when built-in trade delays where greater
than zero
>
> a.. operands of arithmetic expressions are evaluated from left to
right again (as it was in 4.30) so statements like this
> (y = 7)*1000 + y;
> (note assignment within expression) do not cause error messages
about uninitialized variable
>
> a.. new feature "Wait for Backfill" in Auto-Analysis window. Causes
scans/explorations/backtests
> to wait for the plugin to finish data backfill.
> The setting applies to real-time plugins only, and only to those
that support
> this feature.
>
> a.. three new versions of plugins that support 'wait for backfill'
feature are included in the beta archive:
> eSignal plugin 1.5.0
> myTrack plugin 1.5.3
> IQFeed plugin 1.3.0
>
> 'Wait for backfill' feature is not supported by QT plugin, and it
won't be supported because
> QuoteTracker has no interface to allow forcing backfills from 3rd
party applications.
>
> a.. other minor fixes
>
> Best regards,
> Tomasz Janeczko
> amibroker.com
>
> AmiBroker 4.39.0 Beta Read Me
> June 21, 2003 15:48
>
> THIS IS A BETA VERSION OF THE SOFTWARE. EXPECT BUGS !!!
>
> AGAIN: THIS IS A 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 4.39.0 beta" written
in the About box.
>
> See CHANGE LOG below for detailed list of changes.
>
> HELP ON NEW FEATURES
> 'WAIT FOR BACKFILL' FEATURE
>
> The users of eSignal, myTrack and IQFeed real-time plugins may now
check "wait for backfill" box in the Automatic analysis window and
all scans, explorations and backfills will wait for completion of
backfill process for given symbol. This flag has no effect on
databases that do not use plugins (external data sources) or use end-
of-day plugins (like FastTrack, QP2, TC2000/TCNet, etc). This flag
has also no effect when using QT plugin due to the fact that
QuoteTracker manages backfills by itself and does not provide any
control of backfill process to 3rd party applications.
>
>
> 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 depends 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.
>
> This default behaviour can be however overriden using global and
local keywords (introduced in 4.36) - see example 2.
>
> 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 );
>
>
> Example 2: Using local and global keywords to override default
visibility rules:
>
> VariableA = 5; // implict global variable
>
> function Test()
> {
> local VariableA; // explicit local variable with the same
identifier as global
> global VariableB; // explicit global variable not defined earlier
> // may be used to return more than one value
from the function
>
> VariableA = 99;
> VariableB = 333;
> }
>
> VariableB = 1; // global variable
>
> "Before function call";
> "VariableA = " + VariableA;
> "VariableB = " + VariableB;
>
> Test();
>
> "After function call";
> "VariableA = " + VariableA + " (not affected by function call )";
> "VariableB = " + VariableB + " (affected by the function call )"
>
> 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 4.39.0 (as compared to 4.38.0)
>
> a.. added Param dialog to AA window. Note that AA-defined
parameters are reset back to defaults only when you LOAD the formula
from the file or when you click on 'Reset' button in Parameter
dialog.
>
> b.. colorAqua now has correct value of 36
>
> c.. when Printing charts (or using Print Preview ) in Real Time
mode,
> auto-refresh is temporarily disabled to avoid problems with
printing
>
> d.. fixed problem with non-updating last bar of trade arrays by
Equity(1)
> applied in exploration when built-in trade delays where greater
than zero
>
> e.. operands of arithmetic expressions are evaluated from left to
right again (as it was in 4.30) so statements like this
> (y = 7)*1000 + y;
> (note assignment within expression) do not cause error messages
about uninitialized variable
>
> f.. new feature "Wait for Backfill" in Auto-Analysis window.
Causes scans/explorations/backtests
> to wait for the plugin to finish data backfill.
> The setting applies to real-time plugins only, and only to those
that support
> this feature.
>
> g.. three new versions of plugins that support 'wait for
backfill' feature are included in the beta archive:
> eSignal plugin 1.5.0
> myTrack plugin 1.5.3
> IQFeed plugin 1.3.0
>
> 'Wait for backfill' feature is not supported by QT plugin, and it
won't be supported because
> QuoteTracker has no interface to allow forcing backfills from 3rd
party applications.
>
> h.. other minor fixes
>
> CHANGES FOR VERSION 4.38.0 (as compared to 4.37.0)
>
> a.. new setting for candlestick appearance:
> Tools->Preferences->Charting
> "Use distinct color for" : "None, up candle hollow" -
> it plots entire candle with one color but leaves interior of UP
candle body hollow.
>
>
> b.. added export chart image to PNG (portable network graphics)
file
> Edit->Image->Export to PNG file
> (Please don't ask me to add GIF support. GIF is patented and
requires $3500 license fee for Unisys. PNG is free, supported by all
browsers, smaller and better )
>
>
> c.. added 'send chart by e-mail' feature
> Edit->Image->Send by email
> and
> File->Send chart via e-mail
>
>
> d.. fixed positioning of arrows in image copies (Edit->Image-
>Copy)
>
> e.. fixed crash occurring when printer device context did not
support bit blit copies. added very simple arrow line drawing for
that case (will be improved in future releases)
>
> f.. fixed bug in handling Null with new constructs: if, while and
for.
> In pre-4.38 versions Null used in if, while for was treated as
True, which was wrong
> if( Null ) _TRACE("WRONG");
> else _TRACE("CORRECT");
> Now Null in if, while, for is treated as False.
> g.. numbers (floats) are now automatically 'upsized' to arrays on
first use of l-value array subscript operator without causing error.
> Also r-value subscript can be applied to numbers and return the
number itself without causing error, but the underlying variable
remains just a single number.
>
> This allows to easily intialize arrays to any value without need
to write loops.
>
> Example 1:
> in previous versions you would need to write:
>
> for( i = 0; i < BarCount; i++ ) myarray[ i ] = 0 ; // fill with
zeros
> myarray[ 5 ] = 6; // write value to 5th element of the array
>
> now you can write simply:
>
> myarray = 3; // initialize, at this moment myarray is just a
number
> myarray[ 5 ] = 6; // write value to 5th element of the array, the
variable is automatically
> // upsized to array and all elements are filled with a numeric
value
> // that was originally placed in myarray variable
>
> /* myarray is holds now the array filled with values of 3 except
element 5 that has value of 6 */
>
> mynumber = 5;
> test = mynumber[ 7 ]; // previous versions would give an error
message here
> // now subscript operator for r-value numeric variable
> // is allowed and returns just the number
> // and variable is not upsized to array unless appears on left
side
> // of assignment (l-value)
> /* mynumber variable here is still a number */
> WriteVal( test );
>
> CHANGES FOR VERSION 4.37.0 (as compared to 4.36.0)
>
> a.. printing improved, now all open indicator panes are printed
and resolution is increased
> b.. Edit->Copy As Image and Edit->Copy As Metafile now generate
an image consisting of all indicator panes (not just one)
> c.. fixed problem with non-resetting sort arrows in AA window
> d.. fixed sometimes occuring crash Signal() function
> e.. increased size of error message text buffer to prevent
overflow when reporting syntax errors in formulas having long
unwrapped lines.
> f.. grid lines are drawn with fine dots instead of small dashes
(screen output only)
> g.. new AFL functions:
> GetCategorySymbols( category, index )
> - retrieves comma-separated list of symbols belonging to given
category
>
> supported categories:
> categoryMarket categoryGroup categorySector categoryIndustry
categoryWatchlist
> categoryFavorite categoryIndex
>
> index = (market/group/industry/sector/watchlist number)
> 0..255 for categoryMarket, categoryGroup, categoryIndustry
> 0..63 for categorySector, categoryWatchlist
> ignored for categoryFavorite, categoryIndex
>
> StrExtract( list, item )
> - extracts given item (zero-based) from comma-separated string.
>
> Example:
> StrExtract( "MSFT,AAPL,AMD,INTC", 2 )
> will return AMD
>
> StrExtract( "MSFT,AAPL,AMD,INTC", 0 )
> will return MSFT
>
> StrExtract( "MSFT,AAPL,AMD,INTC", 200 )
> will return empty string ""
>
> + other minor fixes
>
> Example code for GetCategorySymbols and StrExtract:
>
> /* note: if given watch list contains lots of symbols
> ** performance may be poor
> */
> function CreateAverageForWatchList( listnum )
> {
> // retrive comma-separated list of symbols in watch list
> list = GetCategorySymbols( categoryWatchlist, listnum );
>
> Average = 0; // just in case there are no watch list members
>
> for( i = 0; ( sym = StrExtract( list, i ) ) != ""; i++ )
> {
> f = Foreign( sym, "C" );
> if( i == 0 ) Average = f;
> else Average = Average + f;
> }
>
> return Average / i; // divide by number of components
> }
>
> Plot( CreateAverageForWatchList( 1 ), "Avg of WL 1",
colorGreen );
>
> CHANGES FOR VERSION 4.36.0 (as compared to 4.35.0)
>
> a.. fixed problem with affecting 2 or more identifiers
referencing the same array when using l-value subscript operator [].
Thanks Herman for pointing this out
> b.. global and local keywords - for explicit visibility/scope
declarations
> Allow to override default scope rules that assume that variables
defined outside function are global, while those identifiers that
appear for the first time inside functions are local.
>
> Syntax:
>
> local var1 [, var2, ... ] ;
> global var1 [, var2, ... ] ;
>
> (as you can see you can declare more than one variable in one
line.
>
> Note: using these keywords outside function definition has no
meaning
> (global scope is used).
>
> Example:
>
> VariableA = 5; // implict global variable
>
> function Test()
> {
> local VariableA; // explicit local variable with the same
identifier as global
> global VariableB; // explicit global variable not defined earlier
> // may be used to return more than one value
from the function
>
> VariableA = 99;
> VariableB = 333;
> }
>
> VariableB = 1; // global variable
>
> "Before function call";
> "VariableA = " + VariableA;
> "VariableB = " + VariableB;
>
> Test();
>
> "After function call";
> "VariableA = " + VariableA + " (not affected by function call )";
> "VariableB = " + VariableB + " (affected by the function call )";
>
> c.. syntax highligting modified so keywords: #include, if, else,
while, do, function, procedure, global, local, return are colorised
differently than built-in constants or functions. Corresponding
color/style setting added to Preferences->Editor
>
>
> d.. #pragma nocache
> pre-processor command added to switch off #include file caching
mechanism.
> Note: between '#pragma' and 'nocache' there must be exactly
SINGLE space
> Note 2: disabling caching may slow down execution of the formula
(especially
> in indicators)
> Note 3: #pragma nocache must be placed before #includes
>
> Example:
> #pragma nocache
> #include <myfile.afl>
>
> a.. single line comments now work with #includes (and #pragma
too) so you can comment out include in regular way:
> //#include <something> - will not include
>
>
> b.. changed error message from "unknown identifier"
to "Variable 'name' used without having been initialized." which
better decribes the problem.
>
> For example:
>
> function Test( )
> {
> global x;
> x = 3;
> }
>
> WriteVal( x ); // variable used without having been initialized,
> // although declared inside Test() function body
>
>
> Test( ); // during function call the value of 3 is assigned to
variable x
>
> WriteVal( x ); // and now no error is reported
>
> a.. implemented shortcut evaluation of logical operators
> The operands of logical-AND and logical-OR expressions are
evaluated from left to right. Now if the value of the first operand
is sufficient to determine the result of the operation, the second
operand is not evaluated. This is called "short-circuit evaluation."
>
> The left operand of the logical-AND operator is completely
evaluated and all side effects complete before continuing. If the
left operand evaluates to false (0), the other operand is not
evaluated.
>
> The left operand of the logical-OR operator is completely
evaluated
> and all side effects complete before continuing.
> If the left operand evaluates to true (nonzero), the other
operand is not evaluated.
>
> (The above description applies to operands that evaluate to
single boolean value,
> it does not apply to arrays. Operands that evaluate to arrays are
evaluated always )
>
> Example:
> for( i = -3; i < BarCount; i++ )
> {
> // using old versions of AMiBroker you would get subscipt out of
range
> // but now
> // the second operand (C[ i ] > C[ i - 1 ]) is evaluated
> // ONLY if first operand ( i >= 1 ) evaluates to TRUE
>
> if( i >= 1 && C[ i ] > C[ i - 1 ] )
> {
> _TRACE("TEST " + i);
> }
> }
>
>
>
> CHANGES FOR VERSION 4.35.0 (as compared to 4.34.2)
>
> 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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