Checking conditions in an indicator

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05/09/2019 at 2:01 PM #98079 quote
robertogozzi
Moderator

Master
I wrote an indicator to signal when a price crosses over the middle line (50) of RSI for the first time, but the code I wrote always returns 0 (pic 1):
```
IF BarIndex < 1 THEN
   MyCond = 0
ENDIF
MyRsi = Rsi[14](close)
IF MyCond = 0 THEN
   MyCond = MyRsi CROSSES OVER 50
ENDIF
RETURN MyCond
```
I could find this workaround, by adding a dummy condition to test if MyCond=1 (pic 2):
```
IF BarIndex < 1 THEN
   MyCond = 0
ENDIF
MyRsi = Rsi[14](close)
IF MyCond = 1 THEN
ELSE
   MyCond = MyRsi CROSSES OVER 50
ENDIF
RETURN MyCond
```
Why this behaviour (both on v10.3 and beta v11)?

Pic1.jpg Pic2.jpg
05/09/2019 at 3:02 PM #98086 quote

Nicolas
Keymaster

Master

I made a report too.

05/09/2019 at 3:05 PM #98087 quote
pableitor
Participant

Master
It seems that from barindex = 0 to 14 the RSI(14) value is undefined. Just do like this:
```
IF BarIndex < 15 THEN
   MyCond = 0
ENDIF
MyRsi = Rsi[14](close)
IF MyCond = 0 THEN
   MyCond = MyRsi CROSSES OVER 50
ENDIF
RETURN MyCond
```
05/09/2019 at 3:59 PM #98095 quote

Vonasi
Moderator

Master

pableitor wrote:

It seems that from barindex = 0 to 14 the RSI(14) value is undefined.

This was my first thoughts but even if it is undefined then it should just be a case that myCond = 0 and there is no cross of RSI over 50 during the first 14 bars so MyCond should remain at zero but then once the RSI does have a defined value after 14 bars then MyCond should change to a value of 1 once the first cross of 50 happens – but it never changes.

05/09/2019 at 3:59 PM #98096 quote
robertogozzi
Moderator

Master
I can also work it out by clearing MyCond everytime (same as IF BarIndex < 9999999 THEN) :
```
MyCond = 0
MyRsi = Rsi[14](close)
IF MyCond = 0 THEN
   MyCond = MyRsi CROSSES OVER 50
ENDIF
RETURN MyCond
```
but it’s not what I need to do.

Thank you.
05/22/2019 at 10:58 AM #99146 quote
Nicolas
Keymaster

Master
Here is the fixed code:
```
IF BarIndex < 1 THEN
MyCond = 0
ENDIF
MyRsi = Rsi[14](close)

IF MyCond = 0 and barindex >= 14 THEN
MyCond = MyRsi CROSSES OVER 50
ENDIF

RETURN MyCond
```
The problem is that the code tries to check the MyRsi CROSSES OVER 50 condition if the barindex is equal to 1.
But at this moment there is not enough candlestick to calculate RSI.
So it returns that mycond = NaN (Not a Number)
And then we never go back into the loop because IF MyCond = 0 is never true.

robertogozzi thanked this post
05/22/2019 at 11:03 AM #99148 quote

robertogozzi
Moderator

Master

Great Nicolas, thank you!

05/22/2019 at 1:50 PM #99164 quote

GraHal
Participant

Master

So there is no way in an Indicator to have preloadbars?

This will answer a problem I was having with an Indicator a few days ago.
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