Array.Sort not working as expected and no documentation about it?

[PowerGrid]

Hi there,

I have an array to hold different price data and I was trying to sort it, but the result is strange:

1. Before sort, the array values are correctly assigned like this:

MyArray[0] : 8783.75
MyArray[1] : 8777
MyArray[2] : 8790

2. Then I did

Array.Sort(MyArray) without any errors

3 After sort, it prints out:

MyArray[0] : 0
MyArray[1] : 0
MyArray[2] : 0

Any ideas?

Thanks!

[NinjaTrader_ChelseaB]

Hello PowerGrid

If this is an array and not a Series<double>, this would fall under general C# that is not specific to NinjaTrader and may be better suited for a forum on C# programming like StackOverflow..

My guess would be that you are assigning a new empty array to the variable.

Below is a public link to the Microsoft documentation.

https://docs.microsoft.com/en-us/dotnet/api/system.array.sort?view=net-5.0

[PowerGrid]

Hello PowerGrid

If this is an array and not a Series<double>, this would fall under general C# that is not specific to NinjaTrader and may be better suited for a forum on C# programming like StackOverflow..

My guess would be that you are assigning a new empty array to the variable.

Below is a public link to the Microsoft documentation.
https://docs.microsoft.com/en-us/dot...t?view=net-5.0

Thanks ChelseaB, I did look into the MS doc but still no clue... no biggie, I will just write my own sort.

[NinjaTrader_ChelseaB]

Hello PowerGrid,

Are you willing to show the code you are needing assistance with?

[PowerGrid]

Hello PowerGrid,

Are you willing to show the code you are needing assistance with?

Sure thing, here is the piece:

if(aUpperFractal[2] > 0 ) //&& aLowerFractal[3] > 0)
{
Print("Before sort,aUpperFractal[0-2]: " + aUpperFractal[0].ToString() + "||" + aUpperFractal[1].ToString() + "||" + aUpperFractal[2].ToString());
Array.Sort(aUpperFractal);
Print("After sort, aUpperFractal[0-2]: " + aUpperFractal[0].ToString() + "||" + aUpperFractal[1].ToString() + "||" + aUpperFractal[2].ToString());
}

here is the output:

Before sort,aUpperFractal[0-2]: 8783.25||8777||8790
After sort, aUpperFractal[0-2]: 0||0||0

maybe the call "Array.Sort(aUpperFractal)" overloaded aUpperFractal and reset it to default 0s?

Thanks for your time.

[NinjaTrader_ChelseaB]

Hello PowerGrid,

I want to confirm that these are arrays and are not Series<double> objects or some other type of collection.

May I see the declaration of aUpperFractal?

[PowerGrid]

Thanks ChelseaB.

public double[] aUpperFractal = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; //need to initiates

[NinjaTrader_ChelseaB]

Hello PowerGrid,

I'm assuming the array has values set some right?

I've assigned values and tested and the C# array sort works without issue. The error must be with the logic in your script.

Below is a link to a video of the test.

https://drive.google.com/file/d/1z1e7C3oI2ta722NZ0L5OTXSONiRSsbFK/view?usp=drivesdk

[PowerGrid]

Hi ChelseaB,

Thank you so much for the vid! I watched 3 times to make sure the only difference between our code is, I assigned the value of that array under function of OnBarUpates(), could you go one step further to move your array.sort to OnBarUpates() instead of State.Dataloaded() to see what happens when you get a chance?

[NinjaTrader_ChelseaB]

Hello PowerGrid,

C# Arrays still work the same when assigned in OnBarUpdate or any other method. Assigning a value in OnBarUpdate does not change how C# works.

As you requested another video, I have created another video to demonstrate.

https://drive.google.com/file/d/1a5UNx3D44ucbYoriyNIGEJHqUCE4SZz9/view?usp=drivesdk

[PowerGrid]

Hi ChelseaB,

Thanks again for the video! I don't know what to say about this, I can't post the whole thing as this is the way I trade manually for over 3 year, so I guess I will just have to figure out myself what went wrong (or just scape the sort, write my own).

Again, thanks for your help!

[nemnem]

Hey,

He is sorting from low to high... so in a array that is initialised 21x 0 is in your case:

Before Sort --> 8783.25,8777,8790,0,0,0,0,0,....

and after sort:

0,0,0,0,0,0... ...0,0,0,0,0,0,8783.25,8777,8790

as you just print out the first positions the array looks empty but its not is my wild quess.

so try a "array.reverse()" after sort

Cheers

[PowerGrid]

Hey,

He is sorting from low to high... so in a array that is initialised 21x 0 is in your case:

Before Sort --> 8783.25,8777,8790,0,0,0,0,0,....

and after sort:

0,0,0,0,0,0... ...0,0,0,0,0,0,8783.25,8777,8790

as you just print out the first positions the array looks empty but its not is my wild quess.

so try a "array.reverse()" after sort

Cheers

WOW! THANK YOU SO MUCH nemnem!! IT WORKED!

After my post, I never come back till now and just saw your reply, what a logic error in my side... anyway, it totally worked!