decimal place rounding off

how to round of a number into 2 decimals places without using the round function?

Answer 1

[Rik]

Why not use the round function?

You could use floor, ceil, or fix instead, but that would be cheating a bit.

Anyway, you can use the code below:

rounded_value=str2double(sprintf('%.2f',value));

[Lucy Hannah]

no i mean for example i have 3.1425. I want to round it of into 3.14 only, if i use floor(a*100)/100 it will become 3.1400

[Adam]

floor( 3.1425 * 100 ) / 100

works fine for me. But then I would always just use the round function anyway since that is precisely what it is there for!

[Stephen23]

"...if i use floor(a*100)/100 it will become 3.1400"

How numbers are displayed is controlled by the format command, where the default setting is short. You can change the format setting and you might get what you want:

>> format short g
>> floor(3.1425*100)/100
ans = 3.14

It is also important to note that this numeric value does not actually exist: what you see displayed is only an approximation of the binary floating point number that is actually stored in memory. Remember, how data is displayed is a totally different thing to how it is stored in memory!