What have I done wrong?

[David Vels]

Heeeelp!!! All I'm trying to do is have a green arrow belowbar when macd turns up and red arrow abovebar for when it turns down. I tip my hat to those of you who have a grasp of this coding thingy. I've got long way to go

Thanks
David

[mbuta]

David,

There are several things [problems] with your code:
a/ you address myRef as array, when is not declared as such [maybe EFS takes it as array, but not documented],
b/ you did not declare your macd as global var and it should,
c/ you refer to "macd" as a regular var, when it is a series and should use "getValue"

Correct those and will work.
Something like:

var stMACD=macd(x,y,z);

Then, in main

if (stMACD.getValue(0)>stMACD.getValue(-1)) {...}
else if (....) {...}

Good Luck!

[ACM]

Mihai

a/ you address myRef as array, when is not declared as such [maybe EFS takes it as array, but not documented],

FWIW myRef is an array in this case because the script is returning multiple values.
The functionality of ref() as an array is documented in this article in the EFS KnowledgeBase and a complete example of its use as an array is provided in this article also in the EFS KnowledgeBase
Alex

Originally posted by mbuta
David,

There are several things [problems] with your code:
a/ you address myRef as array, when is not declared as such [maybe EFS takes it as array, but not documented],
b/ you did not declare your macd as global var and it should,
c/ you refer to "macd" as a regular var, when it is a series and should use "getValue"

Correct those and will work.
Something like:

var stMACD=macd(x,y,z);

Then, in main

if (stMACD.getValue(0)>stMACD.getValue(-1)) {...}
else if (....) {...}

Good Luck!

[ACM]

Re: What have I done wrong?

David
While the use of ref() is technically correct it is not required in this case. This is because unlike the script you were working on in this thread where Filt was a single value and not a series (which means it did not store historical values of itself) the macd() function instead creates a series which means that you can access its prior values using the getValue() method. If for example you declare the MACD study as follows

var myMACD = macd(12,26,9); 

you can then retrieve any of its prior values in the following way

myMACD.getValue(0)//value of myMACD at the current bar
myMACD.getValue(-1)//value of myMACD at the prior bar
myMACD.getValue(-2)//value of myMACD two bars ago
//etc 

Mihai's suggestion will allow you to identify when the the MACD is rising or falling however it is not quite complete as is because the arrows will be drawn on every bar in which the MACD is rising or falling rather than just at the turning points.
So what you need to do in a case like this is to create a condition that is unique eg

if(myMACD.getValue(-1) < myMACD.getValue(-2) && myMACD.getValue(0) > myMACD.getValue(-1){
//if the MACD of one bar ago was less than the MACD of two bars ago and the current MACD is greater than 
//the MACD at the prior bar
    drawShape(....);
} 

which will allow you to identify the specific point when the MACD is turning (upwards in the example). You would then write an opposite condition for when the MACD turns downwards.
This way the arrow will be drawn only on the bars in which the MACD has turned and not on every bar.
Having said that even this solution is not quite complete because if you are running the script in real time the MACD could turn upwards or downwards intrabar - which would draw the arrow - but then at the close of the bar it could continue in its prior direction. Since in the above code there is no provision to remove the arrow this would remain on the chart even if the MACD has not reversed its course. If you then reloaded the efs you would see those shapes disappear because the conditions would no longer be true on historical bars.
So the logic would need to be as follows

if(myMACD.getValue(-1) < myMACD.getValue(-2) && myMACD.getValue(0) > myMACD.getValue(-1)){
//if the MACD of one bar ago was less than the MACD of two bars ago and the current MACD is greater than 
//the MACD at the prior bar
    drawShape(Shape.UPARROW, myMACD.getValue(0), Color.blue, rawtime(0));
}else{
    removeShape(rawtime(0))
} 

This way if the condition is true the arrow will be drawn and if at any point during that bar the condition is no longer true the arrow will be removed
Note that in the above example I replaced the AboveBar1 location parameter with the value of myMACD at the current bar. This is because AboveBar1, BelowBar1, etc are referred to the price bars and would draw the arrows completely outside of the range of the MACD indicator pane.
Alex

Originally posted by David Vels
Heeeelp!!! All I'm trying to do is have a green arrow belowbar when macd turns up and red arrow abovebar for when it turns down. I tip my hat to those of you who have a grasp of this coding thingy. I've got long way to go

Thanks
David

[David Vels]

Thankyou Mihai and Alex for your prompt replies. Both of your answers have been very educational. For whatever reason I was unable to get both uparrows and downarrows working in the same study. What I've done is save them as two separate studies (MACD-UP and MACD-DOWN) and then merge them on the chart and this works fine.

Many thanks again
David

[ACM]

David
You are most welcome
Post the script as you have modified and I or someone else can take a look at it and provide you with some guidance
Alex

Originally posted by David Vels
Thankyou Mihai and Alex for your prompt replies. Both of your answers have been very educational. For whatever reason I was unable to get both uparrows and downarrows working in the same study. What I've done is save them as two separate studies (MACD-UP and MACD-DOWN) and then merge them on the chart and this works fine.

Many thanks again
David