Double difference strange results

[ninjo]

Hello,

I am trying to obtain the difference between two doubles and NT8 return stranges results:

    
double theDif =  0.709 - 0.7091;
Print("theDif--> "+ theDif);

And the Output result is:

theDif--> -9,9999999999989E-05


The result would be -0,0001



What I am doing bad? Thank you.

[ninjo]

I solved it with Math.Round function:

double theDif =  Math.Round( 0.709 - 0.7091, 4);

The problem is that I want to claculate the number of ticks between two chart prices.

Math.Round( 0.709 - 0.7091, 4) / TickSize

Its works and return: -1


In this case the price have 4 decimals, but how could I set for all markets??

Thank you

[NinjaTrader_Jim]

Hello ninjo,

Thanks for your post.

This mathematical behavior is expected with floating point arithmetic. We have some various tips on working with floating point arithmetic in our Tip page below.

Floating point math - https://ninjatrader.com/support/help...arithmetic.htm

Rounding the result to your expectation is viable. For being able to identify the number of digits needed for the rounding precision, you could follow an approach similar to those suggested in the publicly available resource below to get the number of significant digits in TickSize.

Finding the number of places after the decimal point of a number - https://stackoverflow.com/questions/...nt-of-a-double

Please let us know if we can be of further assistance.

[koganam]

I solved it with Math.Round function:

double theDif = Math.Round( 0.709 - 0.7091, 4);

The problem is that I want to claculate the number of ticks between two chart prices.

Math.Round( 0.709 - 0.7091, 4) / TickSize

Its works and return: -1


In this case the price have 4 decimals, but how could I set for all markets??

Thank you

Why not just use the NS provided function, RoundToTickSize()?

ref: https://ninjatrader.com/support/help...toticksize.htm