With drawing functions, you can plot the results of your program on the screen (on a chart). All drawing functions need several inputs that define the name of the study object and where it is positioned on the chart. You can also use them to remove a specific study object from the chart.

Note             The latest value of every study object that is plotted on the chart can also be shown in study columns in a price page.

Drawing functions do not return any values and therefore are usually used on their own, that means the function call makes up a complete command statement.

DrawLine(Name, Level)

Draws a line study object.

DrawArea(Name, TopLevel, BottomLevel)

Draws an area study object.

DrawMarker(Name, PriceArrow, Orientation, MarkerText)

Draws a marker study object.

EraseLine(LineName)

Removes a line study object.

EraseArea(AreaName)

Removes an area study object.

EraseMarker(MarkerName)

Removes a marker study object.

SetLineProperty(Name, Property, Value)

Changes the appearance of a line study object.

SetAreaProperty(Name, Property, Value)

Changes the appearance of an area study object.

RGB(R, G, B)

Defines a custom color.

ResetLineProperty(Name, Property)

Resets a property of a line study object to its default value.

ResetAreaProperty(Name, Property)

Resets a property of an area study object to its default value.

DrawLine

This function draws a line study object.

A line study object is displayed on the chart as a single line. In price pages, lines are represented as one column per line, showing the value for the latest bar.

The appearance of the line can be changed with the function SetLineProperty. The default settings are defined on the Appearance tab of the Study Editor after saving the study. See also Line Settings.

DrawLine(Name, Level)

Parameters

Name

Text

Defines the name of the line study object. If the first letter of the name is a pound sign, for example "#max", the study object will be visible on the chart but will not be included in the Data Info box (transparent area in the corner of the chart).

 

Level

Numeric

Defines the level at which the line study object is drawn.

Returns

 

Nothing

 

Line study objects are usually used for studies that show on the chart as a line or histogram. The line can be positioned at a level that is calculated anew for each bar, like in the example below (line of the Arms Index TRIN):

DrawLine("TRIN", #movs(middle, period, shift));

You can see here that the input value for the parameter Level of the DrawLine function is the output of another function movs. When you use such constructions, make sure that the return type of the other function matches the input type that is needed. In this case, the movs function produces a numeric output and can therefore be used as the input for the Level parameter, which expects numeric data.

Lines can also be positioned at fixed levels (example: zero line of the Aroon Oscillator):

DrawLine("#0", 0);

DrawArea

This function draws an area study object.

An area study object is displayed on the chart as a shaded, transparent area with two lines at the borders. In price pages, areas are represented by two columns, showing the Upper and Lower values for the latest bar.

The appearance of the area can be changed with the function SetAreaProperty. The default settings are defined on the Appearance tab of the Study Editor after saving the study. See also Area Settings.

DrawArea(Name, TopLevel, BottomLevel)

Parameters

Name

Text

Defines the name of the area study object. If the first letter of the name is a pound sign, for example "#max", the study object will be visible on the chart but will not be included in the Data Info box (transparent area in the corner of the chart).

 

TopLevel

Numeric

Defines the level at which the top border line of the area study object is drawn.

 

BottomLevel

Numeric

Defines the level at which the bottom border line of the area study object is drawn.

Returns

 

Nothing

 

An area study object is used for studies such as the Bollinger Bands or the RSI, often in combination with a line study object:

DrawLine("RSI", rsi(Source, period, n));
DrawArea("#Upper", upperLevel, 100);
DrawArea("#Lower", lowerLevel, 0);

Note             In the Study Editor, you have the possibility to activate the Percentage Mode for your area: The area will then be displayed with percentage values instead of absolute values, e.g. with the top border at 75% and the bottom border at 25%. The border lines of areas in percentage mode are not influenced by changes in the vertical price scale, they will always cover the set percentage of the chart pane, regardless of the settings of the vertical price scale.

DrawMarker

This function draws a marker study object.

A marker study object is displayed on the chart as a combination of two arrows (up/down arrow and price arrow) and marker text. In price pages, markers are represented by three columns, showing the orientation of the up/down arrow, the marker text, and the price level of the price arrow.

The standard appearance of the marker can be defined on the Appearance tab of the Study Editor after saving the study. See also Marker Settings.

DrawMarker(Name, PriceArrow, Orientation, MarkerText)

Parameters

Name

Text

Defines the name of the marker study object. If the first letter of the name is a pound sign, for example "#max", the study object will be visible on the chart but will not be included in the Data Info box (transparent area in the corner of the chart).

 

PriceArrow

Numeric

Defines the level at which the price arrow is displayed.

 

Orientation

Boolean

Defines the orientation of the up/down arrow that is drawn. If the value is True, an up arrow will be drawn; if the value is False, a down arrow will be drawn.

 

MarkerText

Text

Defines the marker text that is displayed below or above the up / down arrow.

Returns

 

Nothing

 

Marker study objects are typically used for displaying the signals on a chart. For example, the candlestick pattern Hammer uses a marker study object:

DrawMarker("Hammer_TM", Source.Close, True, "Hammer");

This example code draws an upwards oriented arrow which shows up under the name "Hammer_TM" in TeleTrader WorkStation. The price arrow is usually positioned at a certain price level of the underlying symbol (here at the Close).

If you want to use both an upwards and a downwards oriented arrow within one study, the two marker objects must be referred to with the same name but use a different orientation:

DrawMarker("BuySellArrow", Source.Close, True, "Buy");
DrawMarker("BuySellArrow", Source.Close, False, "Sell");

EraseLine

This function removes a specific line study object from the chart. The line study object does not have to be drawn in the same program in that it is later removed – it must only be referred to with its correct name.

EraseLine(LineName)

Parameters

LineName

Text

Specifies the name of the line study object that should be removed.

Returns

 

Nothing

 

To remove a line from the screen, it must first be drawn by the function. For example, if you draw a line called "TestLine", you can later remove it by using its name:

DrawLine("TestLine", TestLineLevel);

{... code to calculate MyRealLevel ... }

If IsValid(MyRealLevel) Then
Begin
   EraseLine("TestLine");
   DrawLine("RealLine", MyRealLevel);
End;

In this example, you first draw a "TestLine". Then you try to compute the real line level – if the result is valid, you erase the "TestLine" and instead draw a "RealLine".

EraseArea

This function removes a specific area study object from the chart. The area study object does not have to be drawn in the same program in that it is later removed – it must only be referred to with its correct name.

EraseArea(AreaName)

Parameters

AreaName

Text

Specifies the name of the area study object that should be removed.

Returns

 

Nothing

 

EraseMarker

This function removes a specific marker study object from the chart. The marker study object does not have to be drawn in the same program in that it is later removed – it must only be referred to with its correct name.

EraseMarker(MarkerName)

Parameters

MarkerName

Text

Specifies the name of the marker study object that should be removed.

Returns

 

Nothing

 

For example, if you want to show only the most recent occurrence of a marker on the screen, you can erase all previously drawn markers:

{Remember when the last signal was triggered}
lastSignalOn = lastSignalOn[1];

{Add some conditions to trigger the signal under certain conditions}
movs_fast[0] = #movs(Source, 9, 0);
movs_slow[0] = #movs(Source, 18, 0);

If movs_fast Crosses movs_slow Then
Begin
{When conditions are triggered, draw new marker and remember its position, calculate distance to last marker and erase old marker}      lastSignalOn = CurrentBar;
   DrawMarker[0]("MACross",Source[0], True, "Cross");
   distance = CurrentBar - lastSignalOn[1];
   EraseMarker[distance]("MACross");
End;

SetLineProperty

This function lets you change the properties of a specific line study object. It must be referred to with its correct name. The properties set by this function override the settings on the Appearance tab of the Study Editor. See also Line Settings.

SetLineProperty(Name, Property, Value)

Parameters

Name

Text

Specifies the name of the line study object that should be changed.

 

Property

Special

Specifies the line property that you want to change. Use one of the properties listed below:

Weight or Width

Style

Color

 

Value

Special

Defines the value that you want to set for the specified property. The following options are available:

Weight                    Number between 1 and 4

Style                        Solid, Dash, Dot, DashDot

Color                        clrBlack, clrGray, clrSilver, clrWhite, clrNavy, clrBlue, clrTeal, clrAqua, clrOlive, clrGreen, clrLime, clrPurple, clrMagenta, clrRed, clrMaroon, clrYellow or use the function RGB to define a custom color (see RGB function)

Returns

 

Nothing

 

You can for example use this function to change the appearance of a line based on certain conditions. The following example shows a "Volume" line that changes its color to green when the current volume exceeds the average volume of the last 10 bars:

DrawLine("Volume", Source.Vol);

If Source.Vol > Average(Source.Vol, 10) Then
   Begin
          SetLineProperty("Volume", Color, clrGreen);
          SetLineProperty("Volume", Width, 3);
   End
Else
          SetLineProperty("Volume", Style, DashDot);

SetAreaProperty

This function lets you change the properties of a specific area study object. It must be referred to with its correct name. The properties set by this function override the settings on the Appearance tab of the Study Editor. See also Area Settings.

SetAreaProperty(Name, Property, Value)

Parameters

Name

Text

Specifies the name of the area study object that should be changed.

 

Property

Special

Specifies the area property that you want to change. Use one of the properties listed below:

Weight or Width

Style

Line1Color

Line2Color

FillColor

FillTransparency

 

Value

Special

Defines the value that you want to set for the specified property. The following options are available:

Weight                    Number between 1 and 4

Style                        Solid, Dash, Dot, DashDot

Colors                     clrBlack, clrGray, clrSilver, clrWhite, clrNavy, clrBlue, clrTeal, clrAqua, clrOlive, clrGreen, clrLime, clrPurple, clrMagenta, clrRed, clrMaroon, clrYellow or use the function RGB to define a custom color (see RGB function)

Transparency       Number between 0 and 100

Returns

 

Nothing

 

The following example shows how to set the transparency of an area depending on the current bar position:

movs1 = #movs(Source, 50, 0);
movs2 = #movs(Source, 5, 0);
pos = CurrentBar/LastBar*100;

DrawArea("Area", movs2, movs1);
SetAreaProperty("Area", FillTransparency, 100 - pos );

RGB

This function lets you define a custom color that can be used in the functions SetLineProperty and SetAreaProperty.

RGB(R, G, B)

Parameters

R

Numeric

Number between 0 and 255 (Red component)

 

G

Numeric

Number between 0 and 255 (Green component)

 

B

Numeric

Number between 0 and 255 (Blue component)

Returns

 

Numeric

 

The following example shows the definition of a HeatColor with the RGB function. The HeatColor changes with the position of the current bar and can later be used to color lines or areas.

{ Define HeatColor }

bar = CurrentBar;

If bar <= 255 Then
   HeatColor = RGB(bar, 0, 0)
Else If bar <= 510 Then
   HeatColor = RGB(255, bar, 0)
Else If bar <= 765 Then
   HeatColor = RGB(255, 255, bar)
Else
   HeatColor = RGB(255, 255, 255);

{ Use in Line }

DrawLine("HeatLine", Source.Close);
SetLineProperty("HeatLine", Color, HeatColor);

ResetLineProperty

This function resets the specified line property of a line study object to its default value (that is, the value defined on the Appearance tab of the Study Editor).

ResetLineProperty(Name, Property)

Parameters

Name

Text

Specifies the name of the line study object that should be reset to default.

 

Property

Special

Specifies the line property that you want to reset to default. Use one of the properties listed below:

Weight or Width

Style

Color

Returns

 

Nothing

 

ResetAreaProperty

This function resets the specified area property of an area study object to its default value (that is, the value defined on the Appearance tab of the Study Editor).

ResetAreaProperty(Name, Property)

Parameters

Name

Text

Specifies the name of the area study object that should be reset to default.

 

Property

Special

Specifies the area property that you want to reset to default. Use one of the properties listed below:

Weight or Width

Style

Line1Color

Line2Color

FillColor

FillTransparency

Returns

 

Nothing