Round value ???

Dear all,

I have to round a number to a specified number of decimal points.Anybody can help me??

Thank you

Answer 1

[Daniel Shub]

There are a number of submissions on the FEX:

http://www.mathworks.com/matlabcentral/fileexchange/?term=round

Two that look promising are:

http://www.mathworks.com/matlabcentral/fileexchange/4261-round2

and

http://www.mathworks.com/matlabcentral/fileexchange/26212-round-with-significant-digits

Answer 2

[Walter Roberson]

That cannot be done exactly in binary floating point arithmetic. Just the same way that you cannot exactly represent 1/3 in a fixed number of decimal digits, 1/100 cannot be exactly represented in binary digits.

It is possible to display something with two decimal places, such as by using

disp(sprintf('%.2f', 343.945584))

but you cannot store 343.95 exactly in a floating point number: try

sprintf('%.99f\n', 343.95)

and notice that it is not exactly 343.95 that is stored.

If you do not mind that you can only numerically get a close approximation, then use:

round(N*100)/100

[Image Analyst]

Walter, as you know this is a frequently asked question, since you've repeated it bazillions of times. Yet it's not in the FAQ (that I could find anyway). I'm thinking it should be added to section 6 on Math/Algorithms. What do you think? You can add it, or I could if you want.

Answer 3

[Pritesh Shah]

Also, Please see Cell, fix and round function for the same. If you want decimal point fix,

Also, You can you format function.

Thank you

[Walter Roberson]

I think you mean ceil rather than cell.

The "format" function cannot be used to get a precise number of decimal places, except for "format bank"