how to round to 2 decimal?
Deo
double numbers to 2 decimals
Deo
Walter Roberson
>hey, how can I set my matlab program to round all the
>double numbers to 2 decimals
You cannot. There is no exact representation in floating point
for .01, .02, up to .99, except for 0.25, 0.50, and 0.75 which
have exact representations. If you were to try to round
(say) pi to 2 decimal places then the value stored internally
would not correspond to 3.14 but instead to approximately
3.14 + 2e-15
If you are only attempting to change what is displayed when
you specifically ask to output something, then you can
format the numbers using num2str or sprintf() using a format
such as '%0.2f' .
--
So you found your solution
What will be your last contribution?
-- Supertramp (Fool's Overture)
Paul
message <fqjpru$lpj$1...@canopus.cc.umanitoba.ca>...
x = round((x*100))/100
Paul
message <fqjpru$lpj$1...@canopus.cc.umanitoba.ca>...
x = round((x*100))/100
Jerome Briot
> x = round((x*100))/100
Hi,
>> x=pi;
x = round((x*100))/100
sprintf('%.16f',x)
x =
3.1400
ans =
3.1400000000000001
Jerome (Dut)
Walter Roberson
Walter Roberson <robe...@ibd.nrc-cnrc.gc.ca> wrote:
>If you were to try to round
>(say) pi to 2 decimal places then the value stored internally
>would not correspond to 3.14 but instead to approximately
>3.14 + 2e-15
Small correction: the result is
3.14 + 1.24344978758017532527446746826171875e-16
>> sprintf('%0.60g',3.14)
ans =
3.140000000000000124344978758017532527446746826171875
--
"All human knowledge takes the form of interpretation."
-- Walter Benjamin
Dan Haeg
<fqjpma$66c$1...@fred.mathworks.com>...
> hey, how can I set my matlab program to round all the
> double numbers to 2 decimals
here is one way:
data=round(data*100)/100
rounding functions in matlab:
round
fix
floor
ceil
look in the help for more information.
Walter Roberson
>"Deo " <spl...@hotmail.com> wrote in message
><fqjpma$66c$1...@fred.mathworks.com>...
>> hey, how can I set my matlab program to round all the
>> double numbers to 2 decimals
>here is one way:
>
>data=round(data*100)/100
>> data=pi; data=round(data*100)/100; sprintf('%.60g', data)
ans =
3.140000000000000124344978758017532527446746826171875
Why didn't I get 3.14 exactly? I followed your steps word for word!
Is sprintf broken???
nor ki
Hi Benjamin,
no sprintf is fine the problem occurs by /100. as 100 is no
power of 2 rounding errors occur
this will always occur when you divide.
for an exact rounding try
str2num(sprintf('%5.2f',pi))
which looks strange to me but seems to work
kinor
us
<SNIP more on FP-trash...
> for an exact rounding try
> str2num(sprintf('%5.2f',pi))
> which looks strange to me but seems to work...
does it?
format long;
r=str2num(sprintf('%5.2f',pi))
% r =
% 3.140000000000000
% however,
s=sprintf('%.20f\n',r,3.14)
% s =
% 3.14000000000000010000 % <- result
% 3.14000000000000010000 % <- hand coded
us
Walter Roberson
nor ki <kinor.r...@gmx.de> wrote:
>robe...@ibd.nrc-cnrc.gc.ca (Walter Roberson) wrote in
>message <fqkpbj$72h$1...@canopus.cc.umanitoba.ca>...
>> In article <fqkn97$hnn$1...@fred.mathworks.com>, Dan Haeg
><ha...@msoe.edu> wrote:
>> >"Deo " <spl...@hotmail.com> wrote in message
>> ><fqjpma$66c$1...@fred.mathworks.com>...
>> >> hey, how can I set my matlab program to round all the
>> >> double numbers to 2 decimals
>> >here is one way:
>> >data=round(data*100)/100
>> >> data=pi; data=round(data*100)/100; sprintf('%.60g', data)
>> ans =
>> 3.140000000000000124344978758017532527446746826171875
>> Why didn't I get 3.14 exactly? I followed your steps word
>for word!
>> Is sprintf broken???
>no sprintf is fine the problem occurs by /100. as 100 is no
>power of 2 rounding errors occur
But Dan said that his way worked! Are you saying that he was WRONG?
>this will always occur when you divide.
>> data=3.25;data=round(data*100)/100; sprintf('%.60g', data)
ans =
3.25
Where did the round-off error in Dan's routine go? I can't find it?
Do I need a wider format than %.60g to see it??
>for an exact rounding try
>str2num(sprintf('%5.2f',pi))
>which looks strange to me but seems to work
>> data=str2num(sprintf('%5.2f',pi)); sprintf('%.60g', data)
ans =
3.140000000000000124344978758017532527446746826171875
Why didn't I get 3.14 exactly? I followed your steps word for
word! Is sprintf broken???
--
"Do diddle di do,
Poor Jim Jay
Got stuck fast
In Yesterday." -- Walter De La Mare
carlos lopez
> double numbers to 2 decimals
Aside from the other answers, I believe that you should
clearly state which one is your real wish:
a) perform every calculation in fixed point, using only two
decimals
b) display every final result as a real with just two decimals.
The other answers are related with the option b), but they
do not preclude that all the calculations will be carried
out to full double precision, and only later displayed as
you wish.
On the other hand, if you need something as described in a),
you should consider other approaches. To some extent, two
decimal arithmetic can be simulated with integer arithmetic
after multiplying the inputs by 100. Depending on your
matlab version, it will be simpler (or not) to achieve that.
Let us know about your option: namely a) or b)
Regards
Carlos
Omar U. Florez
where the specifier '%g' avoids showing the last
or 'insignificant' zeros and shows only the two decimals
product of multiplying by 100.
>> sprintf('%g',round(pi*100)/100)
ans =
3.14
"carlos lopez" <clv2clv_...@adinet.com.uy> wrote in
message <fqnaea$370$1...@fred.mathworks.com>...
zia
> sprintf('%g',round(-sorted_values(j)*100)/100)
>
> where the specifier '%g' avoids showing the last
> or 'insignificant' zeros and shows only the two decimals
> product of multiplying by 100.
>
> >> sprintf('%g',round(pi*100)/100)
>
> ans =
> 3.14
>
> message <fqnaea$37...@fred.mathworks.com>...
>
> > "Deo " <spli...@hotmail.com> wrote in message
> > <fqjpma$66...@fred.mathworks.com>...
Hello,
Try this
x = 1.23456
quant(x,2)
function output = quant(number,digit)
output = round(number.*(10 ^ digit))./(10 ^ digit);
--Zia
us
<SNIP another solution - another world...
> Try this
> x =3D 1.23456
> quant(x,2)
you should tell the OP that your solution requires the
neural network tbx...
us
Nasser Abbasi
"us " <u...@neurol.unizh.ch> wrote in message
news:g46etg$pmu$1...@fred.mathworks.com...
humm.. he pasted the one line source code for quant().
"function output = quant(number,digit)
output = round(number.*(10 ^ digit))./(10 ^ digit);"
So one can just copy it and use it. no need for neural netwrok toolbox?
Nasser
D. Weyer
chabdull...@gmail.com
> hey, how can I set my matlab program to round all the
> double numbers to 2 decimals
x=pi;
sprintf('%.2f',x)
now type this code in your m file and run it your output will be:
x
3.14
Nasser M. Abbasi
x does not change in any way after this call.
--Nasser
Marco
so
sprintf('% . 2f',x)
TideMan
Nasser is correct.
After:
sprintf('%.2f',x)
you get 3.14, but x has not changed.
yan mercal
float fc = (float)Math.Round(f * 100f) / 100f;
More about.....
http://net-informations.com/q/faq/round.html
Mercal
"Deo " <spl...@hotmail.com> wrote in message <fqjpgm$3hp$1...@fred.mathworks.com>...
Steven Lord
"yan mercal" <yanm...@yahoo.com> wrote in message
news:ml64f6$d6t$1...@newscl01ah.mathworks.com...
> float fc = (float)Math.Round(f * 100f) / 100f;
The message to which you replied was seven years old and had already
received a number of responses. In addition, your answer appears to be Java
code. While you can call Java from MATLAB, in this case if you're using
release R2014b or later you can just use ROUND. See item 4 in the
Mathematics section of the Release Notes for release R2014b on this page:
http://www.mathworks.com/help/matlab/release-notes.html
--
Steve Lord
sl...@mathworks.com
To contact Technical Support use the Contact Us link on
http://www.mathworks.com
