Conditional Plot() something or nothing

AFL Programming
#1

Hi,

probably something simple but cant get it to work ...
conditions been my biggest struggle in afl
any help appreciated

thanks

Plot( Close, "Price", colorWhite, styleCandle );
Hi_D = TimeFrameGetPrice( "H", inDaily, -1 ); Lo_D = TimeFrameGetPrice( "L", inDaily, -1
x= BarCount -1 ;

// if C > Hi_D do this and nothing else
{
Plot(Hi_D,"",colorGreen,styleDashed|styleNoRescale | styleNoLabel,null,null,0,0,2);
GfxTextOut("ENTER", X+10 , ENTERA );
}

// if C < Lo_D do this and nothing else

{
ENTER = LO_D;
Plot(Lo_D,"",colorRed,styleDashed|styleNoRescale | styleNoLabel,null,null,0,0,2);
GfxTextOut("ENTER", X+10 , ENTERA );
}

#2

As I wrote already many times, bar-by-bar conditional Plot() is not done by not calling Plot() but by passing NULL in places when you don't want plot

So

Plot( IIF( C < Lo_D, Lo_D, Null ), "Title", colorRed );

This is so because you generally WANT to PLOT() but only skip some bars.

Last but not least:

When posting the formula, please make sure that you use Code Tags (using </> code button) as explained here: How to use this site.

Using code button

Code tags are required so formulas can be properly displayed and copied without errors.

#3

Ok thanks
But how do you handle other conditions ? Do they have to be approached the same way?
ie

GfxTextOut("ENTER", X+10 , ENTERA );
need to set the pen to null or text to null somehow?

color = LastValue( IIF( C < Lo_D, colorwhite, null ) );
GfxSelectPen( color ) ;

#4

You need to read this:
http://www.amibroker.com/guide/h_understandafl.html
and
http://www.amibroker.com/guide/a_mistakes.html

It is fundamental to understand the difference between array and scalar value and differences between if-else and IIF IIf function versus if statement
These subjects were addressed dozens of times on the forum and in the manual. Please read.

#5

Ok,

l'm still confused is there an example of a simple way that a condition can call a function or a procedure or you can just set a path to follow under certain circumstances?

IIF( C < Lo_D, Lo_D, ProcedureA,ProcedureB);

or

If (C<Lo_D)
ProcedureA
EndIf

I know those do not work but what does?

#6

Neither.

As explained in documents I pointed out you need a SCALAR VALUE (single number) to use if-else. Neither C or Lo_D are scalar values. These are arrays (multiple values, separate value for each bar). To use if-else you need a value for single bar. Such as Close[ 0 ] - that is the close for very first bar.
Did you read the documents carefully? I mean really carefully. I guess not. You responded in 15 minutes. That is not enough time to read the documents I pointed out.

You really need to read and understand. Posting copy-paste code is useless as it does not make you understand.

There are plenty of examples in the Knowledge Base including

that show how to write text conditionally on chart

#7

So GFX is not a good option but it seems more manageable with plottext.
I'll play around with the plottext as for now I get print on both sides since GFX cant be called under a condition.
thanks for the help

#8

This was the code by passing the Null to the color where I didn't need text, instead of using GFX.
It's simple enter signal , that plots a line with the "Enter" on far right. Additional stops , targets can be added using similar code. Still needs some cleanup but the idea is coming together. Its for intra-day trades with a simple momentum daily signal.

// Short Enter
Lo_D = TimeFrameGetPrice( "L", inDaily, -1 );
x= BarCount -1 ;shift =10; width =5;
color = LastValue( IIF( C < Lo_D, colorwhite, colorBlack ) );
bkcolor = LastValue( IIF( C < Lo_D, colorred, colorblack ) );
ENTER = LO_D; ENTERA= LastValue(ENTER); ENTERB= LineArray( x-shift, ENTERA, x-width, ENTERA);
Plot(IIF( C < lo_D, ENTERB, Null ),"",colorRed,styleDashed|styleNoRescale | styleNoLabel,null,null,10,0,2);
PlotText( "ENTER" ,x+10, enterA, color, bkcolor, yoffset = 0 );

#9

@ak47, did you not see this!

#10

Thanks, out of time can't edit it so it stays lol

#11

You could always delete it and re-post it properly!

3 Likes
#12

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