Asked by Talaria
on 6 Aug 2011

how to make matlab output the full number in digits, and not in exponential form?

Answer by Oleg Komarov
on 6 Aug 2011

Accepted Answer

format long

or

sprintf('%16.f',2332456943534324)

Sign in to comment.

Answer by Image Analyst
on 7 Aug 2011

"format long" won't do it. See my example. You can use fprintf() to print to the command window (again, see example), or sprintf() to save into a variable or display in the command window if (and save to "ans") *if* you don't assign a variable to the return value *and* leave off the semicolon.

fprintf('\nFirst, using format long...\n'); format long m = rand(1,3)/1000 fprintf('\nNow, using fprintf()...\n'); fprintf('%.8f ', m) fprintf('\n\nNow, using sprintf()...\n'); sprintf('%.8f ', m)

Results in the command window:

First, using format long...

m = 1.0e-003 *

0.549723608291140 0.917193663829810 0.285839018820374

Now, using fprintf()...

0.00054972 0.00091719 0.00028584

Now, using sprintf()...

ans = 0.00054972 0.00091719 0.00028584

I don't know of anyway to have it operate like you want by default without issuing a command like fprintf().

Walter Roberson
on 7 Aug 2011

format long g

helps. However, integers that exceed 2^53 will be represented in scientific notation with "format long g". To get the full digits of those, you need to use sprintf() or fprintf()

Image Analyst
on 7 Aug 2011

Yes it can help. Sometimes some sneak through even with that (if there would be more than three 0's to the right of the decimal point), like this which I tried:

m =

Columns 1 through 4

0.000538342435260057 0.000996134716626886 7.81755287531837e-005 0.000442678269775446

Columns 5 through 8

0.000106652770180584 0.000961898080855054 4.63422413406744e-006 0.000774910464711502

Sign in to comment.

Answer by Mark Bower
on 20 Oct 2017

Edited by Mark Bower
on 20 Oct 2017

A nice, consistent solution is to use "num2str()". The same call works for both display from the command line:

> val = 1234567890 val = 1.234567890000000e+09 > num2str(val) ans = 1234567890

and also within print statements:

> sprintf(num2str(val)) ans = 1234567890

It also works for floating point numbers:

> val = 123456.789 val = 1.234567890000000e+05 > sprintf(num2str(val)) ans = 123456.789 >

Walter Roberson
on 19 Feb 2018

>> num2str(pi*10^5) ans = '314159.2654'

This is not "full decimal places"

Using num2str() inside sprintf() is redundant.

Stephen Cobeldick
on 20 Feb 2018

sprintf(num2str(val))

The `sprintf` is totally superfluous, it does nothing useful at all here, just slows down the code. In any case, using a proper `sprintf` format string would be quicker than calling `num2str`, and provide more control over the number of digits, so why not do that?

Sign in to comment.

Answer by Walter Roberson
on 19 Feb 2018

For MS Windows and Linux, to get full number of digits and not in exponential form, you need to either use the Symbolic toolbox or you need to use a tool such as https://www.mathworks.com/matlabcentral/fileexchange/22239-num2strexact--exact-version-of-num2str- from the File Exchange. This is crucial for MS Windows, which does a rather poor job of converting exact values; Linux does a better job but still has inaccuracies after a while.

On Mac (OS-X, MacOS), the built in conversion is exact, and you can choose to sprintf() with a '%.1074f' format. For example,

>> sprintf('%.1074f', eps(realmin)) ans = '0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004940656458412465441765687928682213723650598026143247644255856825006755072702087518652998363616359923797965646954457177309266567103559397963987747960107818781263007131903114045278458171678489821036887186360569987307230500063874091535649843873124733972731696151400317153853980741262385655911710266585566867681870395603106249319452715914924553293054565444011274801297099995419319894090804165633245247571478690147267801593552386115501348035264934720193790268107107491703332226844753335720832431936092382893458368060106011506169809753078342277318329247904982524730776375927247874656084778203734469699533647017972677717585125660551199131504891101451037862738167250955837389733598993664809941164205702637090279242767544565229087538682506419718265533447265625'

For larger values you might want to trim out trailing zeros from the converted string

val = pi*1E-200; regexprep( sprintf('%.1074f', val), '0+$', '', 'lineanchors')

ans = '0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003141592653589793111936498419027683964072757959391149845317813416927695644722162706379483043156554579881967829022575831926635177847590589777088086173081089243142930507159490615800591052996089483276727788901006686618108987452642387169053033459820326372299902201815389727889699071056417123601253516892437642498120285079407325647552658339885701180059456745257476645670329996938769926310811984167666114826593537757304481509915842491117931968666219637406979734598283259283758102504979792257699955371208488941192626953125'

Sign in to comment.

Answer by Huw S
on 31 Jan 2017

If you don't need to know all the decimal points, then do your equation inside round.

saves all the other bother of exponentials.

Walter Roberson
on 31 Jan 2017

Unfortunately not the case:

>> format short >> round(2^54) ans = 1.8014e+16 >> format long g >> round(2^54) ans = 1.8014398509482e+16 >> uint64(2^54) ans = uint64 18014398509481984

Sign in to comment.

Answer by Kaveh Vejdani
on 19 Feb 2018

I don't understand why you have accepted the wrong answers. What you're looking for is: format short g

Cheers, Kaveh

Walter Roberson
on 19 Feb 2018

>> format short g >> pi*10^5 ans = 3.1416e+05

That does not appear to satisfy either part of the requirement,

"how to make matlab output the full number in digits, and not in exponential form?"

Kaveh Vejdani
on 19 Feb 2018

Walter Roberson
on 19 Feb 2018

>> format short g >> pi ans = 3.1416

This is **not** "full number in digits"

>> 1000000 ans = 1e+06

this is not even close to being an "absurdly huge number"

format short g gives you at most 5 significant figures.

format long g gives you at most 15 significant figures. It turns out that is not enough in practice to be unique. There are 24 distinct representable values in unique(pi-37*eps:eps:pi+9*eps), all of which display as 3.14159265358979 under format long g. If the goal is to output enough digits to be able to transfer the values exactly in text form, then format long g is not sufficient.

People get caught by this all the time!

format long g T = 0.3 - 0.2 T == 0.1 T - 0.1

T = 0.1 ans = logical 0 ans = -2.77555756156289e-17

People have difficulty understanding why a value that shows up as 0.1 does not compare as equal to 0.1: the limits of format long g have real effects.

Sign in to comment.

Opportunities for recent engineering grads.

Apply Today
## 0 Comments

Sign in to comment.