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I origionally sent this post under a new title of "AlmostEqual( x, y,
ulps = 5 )" , and I received the following message:
"We are unable to deliver the message from < mrdavis9@xxxxxxxxxx> to <amibroker @yahoogroups.com>.Your
message was sent to a group that does not exist. Please check to make sure
you spelled the group name correctly."
This happens every once in a while. Does this
sometimes happen to others on this board?
============================================================
I understand the below explanation to mean that "
ULPS=9" would be roughly 0.00009% accurate.
Therefore, it is my understanding that 0.00009% accuracy is
the LARGEST difference that AlmostEqual(
x, y, ulps = 9 ) will allow. I would appreciate
hearing if this a correct understanding of this new AlmostEqual
function? Ron D
================================================================
AlmostEqual( x, y, ulps = 5 ) is a helper function for comparing
floating point numbers.It returns True if x and y are equal or almost equal upto
defined accurracy (ulps).It is recommended to use this function instead of
equality check (==) as itleads to more reliable comparisons and less headache
caused by IEEE floating pointacurracy issues.
Parameters:x, y - the numbers or arrays to be compared,Ulps stands for
"units in last place" and represents maximum relative error of the comparison.
Since 32 bit IEEE floating point numbers have accurracy of 7 significant digits,
1 unit in last place(ulp) represents relative error of 0.00001 %. The default
value of ulps parameter is 5 which gives roughtly 0.00005% "comparison
sensitivity".
----- Original Message -----
Sent: Friday, September 16, 2005 5:42
PM
Subject: [amibroker] AmiBroker 4.73.0
BETA released
Hello,
A new beta version (4.73.0) of AmiBroker has just
been released.
Best regards, Tomasz
Janeczko amibroker.com
AmiBroker 4.73.0 Beta Read Me
September 17, 2005 0:36
THIS IS A BETA VERSION OF THE SOFTWARE. EXPECT BUGS !!!
Backup your data files and entire AmiBroker folder
first! IMPORTANT NOTE: This version uses new system to store indicators
(in separate files), so old versions will not automatically "see" indicators
created with new version.
INSTALLATION INSTRUCTIONS
IMPORTANT: This archive is update-only. You have to install full
version 4.70 first.
Just run the installer and follow the instructions.
Then run AmiBroker. You should see "AmiBroker 4.73.0 beta" written in the
About box.
Many thanks to all providing detailed descriptions how to reproduce given
bug.
See CHANGE LOG below for detailed list of changes.
CHANGE LOG
- OLE: Window object, new method ZoomToRange( From, To )
ZoomToRange(
From, To ) From and To parameters are of any type that can be converted
to date(you can use string or OLE date for example).
Example code
(JScript):
AB=new ActiveXObject("Broker.Application"); AW =
AB.ActiveWindow; if( AW.ZoomToRange( "2005-04-01", "2005-08-01" ) ) {
WScript.Echo("Zoom successfull" ); }
- Fixed: Chart got shrinked a bit with each overlaid plot, now the Y scale
does not change (unless really needed)
- Fixed: XShift now works correctly with styleOwnScale and
styleLeftScale
- Fixed: Volume chart overlaid on price chart in log scale (overlay) was
compressed to flat line, now it is fixed (volume chart overlay uses linear
scale always)
[#22262]
- AFL: Added AlmostEqual function (completed:
2005-09-16)
AlmostEqual( x, y, ulps = 5 )
this is a helper
function for comparing floating point numbers.It returns True if x and y are
equal or almost equal upto defined accurracy (ulps).It is recommended to use
this function instead of equality check (==) as itleads to more reliable
comparisons and less headache caused by IEEE floating pointacurracy
issues.
Parameters:x, y - the numbers or arrays to be compared,Ulps
stands for "units in last place" and represents maximum relative error of
the comparison. Since 32 bit IEEE floating point numbers have accurracy of 7
significant digits, 1 unit in last place(ulp) represents relative error of
0.00001 %. The default value of ulps parameter is 5 which gives roughtly
0.00005% "comparison sensitivity".
Example code:
if( 1/3
== 0.3333333 ) { printf("32-bit Floating point IEEE exact
equality\n"); }
if( AlmostEqual( 1/3, 0.3333333 ) ) {
printf("Numbers are almost equal\n"); }
Thanks to
Bruce Dawson for his fast routine.
- Optimize() function now checks if min < max, step > 0 and checks
if parameter name is not empty
- Made Time&Sales case insensitive (when "case sensitive tickers"
option is turned off")
- OBV/AccDist/Chaikin functions adjusted to be SetForeign-aware
- OLE: Application object new methods
BOOL LoadLayout( filename
) BOOL SaveLayout( filename )
AB = new
ActiveXObject("Broker.Application"); AB.LoadLayout("C:\\Program
Files\\AmiBroker\\Data\\Layouts\\Default.awl");
- OLE: Window object new property: SelectedTab
AB = new
ActiveXObject("Broker.Application"); AW = AB.ActiveWindow; tabindex =
AW.SelectedTab; // read selected tab AW.SelectedTab = 3; //switch to tab
3 AW.SelectedTab = tabindex; // restore originally selected tab
- Fixed: Exception was generated when GetRTDataForeign was called with
non-existing ticker
- OLE: Window object new methods: LoadTemplate, SaveTemplate
AB =
new ActiveXObject("Broker.Application"); AW =
AB.ActiveWindow; AW.SaveTemplate("Test.abt"); AW.LoadTemplate("Test.abt");
CHANGES FOR VERSION 4.72.1 (as compared to 4.72.0)
- fixed out-of-memory problem sometimes occuring during scan of large
(>512MB) databases
CHANGES FOR VERSION 4.72.0 (as compared to 4.71.1)
- " Currency" field support in ASCII importer
added command:
$CURRENCY USD
and field:
$FORMAT Name,Currency$OVERWRITE
1$AUTOADD 1]
- Added "Additional commands" field in the Import wizard for typing any
extra $- commands that are not available via checkboxes
- Added parameter to AddColumn/AddTextColumn to control column width
AddColumn( ARRAY, "Caption", format = 1.2, color = colorDefault,
bgcolor = colorDefault, width = -1); AddTextColumn( "Text", "Caption",
format = 1.2, color = colorDefault, bgcolor = colorDefault, width = -1
);
- AddToComposte new flag to work when Status("action")== actionPortfolio
(completed: 2005-09-09)
new flag is called
atcEnableInPortfolio
Example:
if( Status("action" ) ==
actionPortfolio )
{ ... Custom backtest mode here
.... AddToComposite( some_array, "~COMPOSITE", "X",
atcFlagEnableInPortfolio | atcFlagDefaults );
}
- AFL added: tanh(), sinh(), cosh() functions
Hyperbolic tangent, sine
and cosine function
- AFL functions: StrToUpper and StrToLower
- Fixed: Tick ASCII import: last tick of previous import was deleted on
subsequent import, now it is corrected
- Function to detect mouse button state
GetCursorMouseButtons()
returns mouse button state at the time when chart formula is
executed
0 - if no mouse button is pressed 1 - if left mouse
button is pressed 2 - if right mouse button is pressed 4 - if middle
mouse button is pressed
plus combinations:3 - left + right5 - left +
middle6 - right + middle 7 - left + right + middle]
- GetRTDataForeign (retrieving values for other symbols)
GetRTDataForeign( "field", "symbol")
- Pane is not deleted if shrinked down to zero (prevents from accidential
deletion of panes)
- Plot function now has xshift parameter that allows to visually shift the
chart past the last bar
Example 20-bar Moving average shifted 10 bars
into the future past the last
bar:
Plot(Close,"Close",colorBlack,styleCandle);Plot(MA(Close,20),
"Shifted MA", colorRed, styleLine, Null, Null, 10 );
Note that shift
occurs during plotting and does not affect source array
- Removed data source selection from preferences because it caused user
confusion way too often
- Stock.Currency available via OLE
- Title variable now supports new special token {{OHLCX}} which is
replaced at runtime by string "Open ..., Hi .... Lo ... Close (...%)"
showing current price
This way it is possible to implement formula
that will show OHLC prices with number of decimal places set in the
preferences.
Example:
SetChartOptions(0,chartShowArrows|chartShowDates); _N(Title
= "{{NAME}} - {{INTERVAL}} {{DATE}} {{OHLCX}} {{VALUES}}" ); Plot( C,
"Close", ParamColor("Color", colorBlack ), styleNoTitle |
ParamStyle("Style") | GetPriceStyle() );
- user-definable number of decimal places in chart titles (completed:
2005-09-09)
Number of decimal places displayed in default chart title is
now user-definable inTools->Preferences->Miscellaneous"Decimal places
in chart titles".
Allowable values: -1 - dynamic mode (number of
decimal places automatically adjusted) 0..6 - fixed number of decimal
places
- QuoteArray resizing now uses heuristic algorithm to minimize memory
fragmentation and increase performance
- atcFlagDeleteValues now highlighted properly in the AFL
editor
CHANGES FOR VERSION 4.71.1 (as compared to 4.71.0)
- fixed compatibility problem with AmiQuote (due to changed order of OLE
properties/method while AmiQuote was using old ones)
- now ASCII importer in $TICKMODE does not delete quotes older than oldest
(first) record in the imported file, so you can safely import tick data from
subsequent files (older first, newest later)
CHANGES FOR VERSION 4.71.0 (as compared to 4.70.5)
- AFL: added GetCursorXPosition() and GetCursorYPosition()
functions
Functions return current mouse cursor position. Values
returned are equal to those visible in the status bar, and these functions
require status bar to be visible. Returned values represent cursor position
at the formula execution time (or few milliseconds before it) and accurracy
is subject to pixel resolution of the screen (first cursor position is read
in screen pixels (integer) and then converted to actual value therefore for
example when screen resolution is 1024x768 maximum obtainable resolution in
X direction is 0.1% and in Y direction 0.13%), also X values are snap to
datetime of nearest data bar.
It only makes sense to use these
functions in indicator/interpretation code.
Using them in AA window
may yield random values.GetCursorXPosition() function returns X position in
DateTime format (the same as used by DateTime() function).You can convert it
to string using DateTimeToStr() function.GetCursorYPosition() returns Y
position (as displayed in Y axis of the chart).
Example:
ToolTip="X="+DateTimeToStr(GetCursorXPosition())
+"\nY="+GetCursorYPosition();
-
AFL: added DateTimeToStr() and StrToDateTime() functions
These
functions allow to convert string to datetime format and vice versa.
Example:
ToolTip="X="+DateTimeToStr(GetCursorXPosition())
+"\nY="+GetCursorYPosition();]
-
Added ability to store charts as .GIF (in addition to PNG)
-
ASCII importer maximum supported line length is increased to 2048
characters
-
Fixed: .aflsafe files didn't get deleted automatically
- Added N-volume bars charts and timeframe support.
Custom N-volume
bar intervals are definable (as usual) in
Tools->Preferences->Intraday.
TimeFrame functions were also
extended to support N-volume bars using new TimeFrameMode() function
calling
TimeFrameMode( 0 );
- switches time frame functions
to time-based operation (the default)
TimeFrameMode( 1 );
-
switches time frame functions to N-tick operation (positive values passed to
TimeFrameSet are treated now as N-tick)
TimeFrameMode( 2 );
-
switches time frame functions to N-volume bar operation (positive values
passed to TimeFrameSet are treated nowas N-volme bars)
Example:
TimeFrameMode( 2 ); TimeFrameSet( 50000 ); //
50'000 share bars.. ...do something ... TimeFrameRestore();
Note: N-volume bars are somewhat weird (compression of data to
N-volume bar may actually deliver MORE output bars - for example if one tick
is 1000 shares and you have specified 100V bars then single tick will be
expanded to TEN 100V bars - ten times original size) TimeFrame functions
are protected against array overrun and will not decompress beyond original
array size (you will get an "Error 47. N-volume bar compressed data longer
than base time frame"). Also switching main time frame to some weird
N-volume bar value will result in limiting the output to maximum twice
original data size(without error message). You should keep that in mind
and avoid using too small N-volume bar intervals that could lead to such
condition. Also due to the nature of N-volume bars the only
TimeFrameSet() function will yield correct N-volume bar values,
TimeFrameGetPrice() may give slightly distorted results. It is also
possible to use n-volume bars in TimeFrame functions without calling
TimeFrameMode() - it is then necessary to specify n-volume bars as negative
number offset by -1000000 (minus one million):
TimeFrameSet( -1000000
- 2000 );
// gives 2000V barsSimilarly formatted negative numbers
will be reported by Interval() function when n-volume bars are selected.
-
OLE: Save As PNG / GIF callable from automation
Example
script:
AB = new
ActiveXObject("Broker.Application"); AB.ActiveWindow.ExportImage("Test.png");
-
Plugin is not called when GetExtraData is used for symbol that has "use
only local database" flag turned on, and NULL is returned instead of an
error
-
Protected against changing application's current working directory by
printing to file
-
Toolbar does not get wrapped when main frame window is resized
-
OLE: Analysis object has new method MoveWindow( x, y, width, height) that
allows to control position and size of automatic analysis window
AB =
new ActiveXObject("Broker.Application"); AB.Analysis.MoveWindow( 10, 10,
200, 200 );
It has some restrictions on size: specified size can not besmaller
than 10x10 pixels and can not be bigger than entire screen
dimensions. Also when "No minimum size for resizing dialogs" box in
UNCHECKED in Tools->Prefs->Misc it won't shink AA window below default
size necessary to fully display all controls.
-
ASCII importer: added ability to import tick data from text files
ASCII importer now allows tick data files to be imported.
Tick data files consist of several records having the same timestamp.This
makes it impossible to use normal import mode which assumes different
(unique) timestampsfor each data row (when same timestamp is found then new
data overwrites old).
To turn on TICK mode you need to add manually
$TICKMODE
1
line to ASCII importer definition file.
$TICKMODE is a special mode of importer that allows to import quotes
that haveduplicate time stamps.
It makes two assumptions: a)
input data should come in the ascending time order (i.e. OLDER records
first, LATEST records last) b) input data should consist of entire tick
history because importer will DELETE any existing quotes (to avoid creating
multiple copies of the same ticks).
Once again: Turning on $TICKMODE 1 will DELETE ANY QUOTES that
already exist in the database and then will import all ticks from input data
file. You have been warned.
For example data files like this:
MOL,0,20050606,162959,16400.0000,16400.0000,16400.0000,16400.0000,2MOL,0,20050606,162959,16400.0000,16400.0000,16400.0000,16400.0000,11MOL,0,20050606,162959,16400.0000,16400.0000,16400.0000,16400.0000,40
Can be imported using the following definition file:
$FORMAT Ticker, Skip, Date_YMD, Time, Open, High, Low, Close,
Volume $SKIPLINES 1 $SEPARATOR , $CONT 1 $GROUP 255 $AUTOADD
1 $DEBUG 1 $TICKMODE 1
Sometimes it happens that input files have invalid timestamps
(seconds > 59).
For
example:
MOL,0,20050606,162970,16400.0000,16400.0000,16400.0000,16400.0000,2
Please
take a closer look at first line shown in this example it has time:16:29:70
(you see 70 seconds !)
So I had to add a special flag to the importer that works around such
data errors.
It is called $ALLOW99SECONDS 1 and will convert all
records with invalid seconds (i.e greater than 59)to 59s. So record
stamped 16:29:70 will be treated as 16:29:59
Now for tick mode to work with such incorrect records you would need to
add two lines to ASCII importer definition:
$TICKMODE 1 $ALLOW99SECONDS 1
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 at
amibroker.com
Please note that this group is for discussion between users only.
To get support from AmiBroker please send an e-mail directly to
SUPPORT {at} amibroker.com
For other support material please check also:
http://www.amibroker.com/support.html
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