Help to understand errors from SUM function.

[burtoninlondon]

Hello,

I am trying to convert a TradingView indicator into NinjaScript so I can use it in a NinjaTrader strategy, this is the indicator https://www.tradingview.com/script/h...o-OPEN-SOURCE/.

I am having trouble converting this particular section of code...

math.sum(avpch * avpch, blength)

blength is an integer and avpch is the value of the Arnaud Legoux Moving Average (ALMA) indicator (which I've got a NinjaScript version from here https://forum.ninjatrader.com/forum/...rom-nt7-to-nt8). This line of code is essentially summing the 'avpch * avpch' ALMA indicator values for each candle within the blength look back period.

math.sum is not available to use in NinjaScript therefore I think the NinjaScript conversion of this code is

SUM(avpch * avpch, blength)[0]

but this is an indicator, not a math function.

I am bringing in the ALMA indicator values by inserting this into (State == State.DataLoaded)

ALMA1 = ALMA(Close);

and assigning the value to a new variable

double avpch = ALMA1[0];

When I try to compile the code I receive two errors:

• The best overloaded method match for 'NinjaTrader.NinjaScript.Indicators.Indicator.SUM( NinjaTrader.NinjaScript.ISeries<double>, int)' has some invalid arguments; and
• Argument 1: cannot convert from 'double' to 'NinjaTrader.NinjaScript.ISeries<double>'

Can you shed any light on the suitability of my code and how I can resolve the errors or is there another way to convert this code into NinjaScript?

Thanks in advance.

Neil

[NinjaTrader_ChelseaB]

Hello burtoninlondon,

Math.Sum() would be a C# method used to sum an array of values. This is available in NinjaScript which is written in C#.

Below is a link to the Microsoft documentation.
https://learn.microsoft.com/en-us/do...ramework-4.8.1

SUM() is a NinjaTrader indicator that sums a Series<double> (like a plot).

Below is a link to the help guide.
https://ninjatrader.com/support/help...mation_sum.htm

You would need to put the values in a series to use this with the SUM() indicator.

https://ninjatrader.com/support/helpGuides/nt8/seriest.htm

[burtoninlondon]

Thanks NinjaTrader_ChelseaB...but unfortunately I can't use Math.Sum() as I receive an error stating that ''System Math' does not contain a definition for 'Sum'' and there isn't an option for 'Sum' in the selection window when I type Math...

Hopefully this image will help...

[NinjaTrader_ChelseaB]

Hello burtoninlondon,

Apologies that would be <Enumerable>.Sum, such as from an array or list.

MyArrayVariableName.Sum()