Float in Blueprint value not expected

anonymous_user_87830da7 · December 4, 2016, 7:49pm

Hey there. Im new to blueprint and programming in generally so if this is something obvious im sry for that.

Im currently working on a project and have come by something i dont seem to understand.
I have made a new project with a new blueprint file and recreated the scenario.
Shortly explain i loop 15 times and for each time i add 0.001 to a float.
The float starts at 1
Whenthe loop comes to 1.01 and 0.001 is added it says : 1.011001 on my screen.
I have uploaded some screenshots that may help explain.

If i set the value to 1.01 and add 0.001 the result is 1.011 which i expect. However not when i do the looping.

Would be grateful for help.

Edit:Picture of Bp is easier to see now i hope

Everynone · December 4, 2016, 8:09pm

Yeah, computers are not good at math. It’s a rounding error you need to learn to live with.

This node may be of use at times.

anonymous_user_5882066e · December 4, 2016, 8:22pm

Blueprints don’t offer more precise floating point data types. If you need it more precise, you need to use C++.

But I doubt you do, if you tell use what you’re trying to do, we might help you.

anonymous_user_87830da7 · December 4, 2016, 8:31pm

Ok, thx for the explaination guys.
I was trying to use this to loop through a csv data table with the main index(or whatever its called) being: 1.00,1.001, 1.002 and so on. I tried use c++ for datatable but failed at it,hehe, so i went for blueprint but i guess im back to start then.
But how come the precision of float being more precise with a single 1.01 + 1.001 compared to iterating/looping and adding 1.001?

anonymous_user_5882066e · December 4, 2016, 8:56pm

You can format your number so that it always has 3 digits after the point: