rounding down using floor

so im using:

floor(10^decimal*(total/AVERAGE_COUNT))/10^decimal;

where:

decimal = 4, AVERAGE_COUNT = 9, total = 8.9289

this entry gives me 0.9920, however the answer should be 0.9921

furthermore, when I just do

total/AVERAGE_COUNT;

it gives me 0.9921 which is correct but i need to use the floor function for the rest of my data.

how do i get around this

[Walter Roberson]

Which MATLAB release are you using, and which operating system?

I get 0.9921 on R2020a on Mac

[marcus peixoto]

I'm on R2020a on Windows

[per isakson]

On my R2018b, Win10 this script

%%
format long
decimal = 4; AVERAGE_COUNT = 9; total = 8.9289;
x = floor(10^decimal*(total/AVERAGE_COUNT))/10^decimal

outputs

x =
   0.992100000000000
>> 

Answer 1

[Dana]

I'm on R2020a on Windows 10 and I also get 0.9921.

Is it possible that total does not equal exactly 8.9289? For example, if total actually equals 8.92889 (which would usually display as 8.9289 in the command window), then you'll end up with 0.9920.