I'm trying divide a value using BigDecimal, when this value is a decimates BigDecimal round this value and I wont to do that. I need the decimates value are shown. For example, if I do divide 10 / 3 = 3.33333, I need shown 3.33 but does show 3.00
How could I do this ?
//Result-> 10 / 2 = 3,3333333
BigDecimal result = new BigDecimal(0);
BigDecimal v1 = new BigDecimal(10);
BigDecimal v2 = new BigDecimal(3);
result = v1.divide(v2, BigDecimal.ROUND_UP);
//output = 3
//I need output = 3.33
The scale of BigDecimals that were initialized with ints is 0, meaning that rounding operations round to unity. With your example, the division rounds up to 4.
Set the scale of the first BigDecimal to 2, which be retained through the division. Also set the rounding mode to "down".
BigDecimal v1 = new BigDecimal(10).setScale(2);
BigDecimal v2 = new BigDecimal(3);
result = v1.divide(v2, BigDecimal.ROUND_DOWN);
Printing results now yields an output of 3.33.
You could have also used the RoundingMode enum as a drop-in replacement for the rounding constants. Additionally, you could have used ROUND_HALF_DOWN, ROUND_HALF_UP, or ROUND_HALF_EVEN (or their RoundingMode equivalents).
You could use a string with the appropriate number of decimal digits to set the scale implicitly.
BigDecimal v1 = new BigDecimal("10.00"); // scale of 2
try to compile and run this java class, it works as you wish:
import java.math.*;
class decimal {
public static void main(String[] args) {
BigDecimal result = new BigDecimal(0);
BigDecimal v1 = new BigDecimal(10);
BigDecimal v2 = new BigDecimal(3);
result = v1.divide(v2,2,BigDecimal.ROUND_HALF_UP);
System.out.println(result);
}
}
output : 3.33
you want two decimal digits this is why I set scale=2
Try to add scale to BigDecimal, like this:
public class User {
public static void main(String[] args) {
BigDecimal result = new BigDecimal(0);
BigDecimal v1 = new BigDecimal(10).setScale(2);
BigDecimal v2 = new BigDecimal(3);
result = v1.divide(v2, BigDecimal.ROUND_DOWN);
System.out.println(result);
}
}
Related
I have a decimal value 46.58 i want it to be like 46.60 or for 46.44 it will be like 46.40.
Tried several ways like like Math class's round function and Bigdecimal but it is not roudning off after decimal values.
BigDecimal bigDecimal = new BigDecimal(value);
bigDecimal = bigDecimal.setScale(2,BigDecimal.ROUND_HALF_UP);
value = bigDecimal.doubleValue();
double value = Math.round(decimalValue);
You first need to round to 1 decimal place using standard half-up RoundingMode and afterwards increase the scale to 2 again:
BigDecimal bigDecimal = new BigDecimal("46.58");
bigDecimal = bigDecimal.setScale(1, RoundingMode.HALF_UP); // bigDecimal == 46.6
bigDecimal = bigDecimal.setScale(2, RoundingMode.UNNECESSARY); // bigDecimal == 46.60
below solution worked for me.
BigDecimal bigDecimal = new BigDecimal("46.58");
bigDecimal = bigDecimal.setScale(1, RoundingMode.HALF_UP);
bigDecimal = bigDecimal.setScale(2, RoundingMode.UNNECESSARY);
double d = bigDecimal.doubleValue();
String valstr = String.format("%.2f%n", d);
System.out.println(valstr);
I need the following results:
10.17111 -> 10.17
10.17445 -> 10.18
I tried BigDecimal and DecimalFormat methods and RoundingMode class:
String value = "10.17111";
BigDecimal bd = new BigDecimal(value);
BigDecimal bdResult = bd.setScale(2, RoundingMode.UP);
String result = bdResult.toString();
System.out.println(result);
Print out = 10.18
Should be = 10.17
double ddd = 10.17111;
DecimalFormat d = new DecimalFormat("#.##");
d.setRoundingMode(RoundingMode.UP);
String outputResult = d.format(ddd).replace(',', '.');
System.out.println(outputResult);
Print out = 10.18
Should be = 10.17
And with BigDecimal:
String value2 = "10.17445";
Print out = 10.18
As I expected
And with DecimalFormat:
double ddd2 = 10.17445;
Print out = 10.17
Should be = 10.18
If you really want to round digit-by-digit and you should really think long and hard about it (and perhaps tell us why if you are so inclined as I'm curious), then you can do any of the following, which I present as a thought exercise rather than as a recommendation that this is mathematically sound which I leave to you to decide for yourself:
1) Write an algorithm which checks from the digit you are rounding to and looks to see if it is a chain of 4's followed by a digit greater (10.44449) than 5 or just a number greater than 5 (10.49). If so round up to 11, otherwise use the normal rules.
2) Use RoundingMode.HALF_UP in a loop or recursively doing one digit at a time. If you have 10.17445, then you define a decimal format #.#### and round. Then #.### and round. Then #.## and round.
The reason there isn't a standard way to do this is because it is not standard.
Just do all of the digits one by one, starting from the end, until you've done as many as you need to do.
public static BigDecimal RoundIt(BigDecimal valueToRound, int precision)
{
BigDecimal result = valueToRound;
for (int i = valueToRound.precision(); i >= precision; i--)
{
result = result.setScale(i, RoundingMode.HALF_UP);
}
return result;
}
My workaround and it works fine:
public static String roundUp(String value) {
BigDecimal bd = new BigDecimal(value.replace(',', '.'));
BigDecimal bdResult = bd.setScale(4, RoundingMode.HALF_UP);
BigDecimal bdResult2 = bdResult.setScale(3, RoundingMode.HALF_UP);
BigDecimal bdResult3 = bdResult2.setScale(2, RoundingMode.HALF_UP);
String result = bdResult3.toString();
return result;
}
I have two double values
double a = 1.07522;
double b = 1.0752;
and rounding multiplier value
public static final double ROUND_MULTIPLIER = 100000.0;
So there always should be 5 decimal places.
I need to subtract two double values and get result as a - b = 0.00002.
How can I do this with using ROUND_MULTIPLIER ?
I tried using BigDecimal as
BigDecimal.valueOf(a).subtract(BigDecimal.valueOf(b)).round(new MathContext((int)ROUND_MULTIPLIER));
but it not always works, sometimes return 2E-16, it returns weird value when try add to second value as below
BigDecimal.valueOf(a).subtract(BigDecimal.valueOf(b + 0.00002)).round(new MathContext((int)ROUND_MULTIPLIER));
I need to use ROUND_MULTIPLIER.
I don't understand why you must use ROUND_MULTIPLYER and what the exact reason of it's existance is, so I can only guess.
Forcing the code to use ROUND_MULTIPLYER:
public static final double ROUND_MULTIPLIER = 100000.0;
public void foobar()
{
double a = 1.07522;
double b = 1.0752;
BigDecimal opA = BigDecimal.valueOf(a);
BigDecimal opB = BigDecimal.valueOf(b);
BigDecimal result = opA.subtract(opB);
result = result.multiply(BigDecimal.valueOf(ROUND_MULTIPLIER));
int cutResult = result.intValue();
result = BigDecimal.valueOf(cutResult / ROUND_MULTIPLIER);
System.out.println(result);
}
The output of this is
0.000020
Is that what you want? The code is definitly object to optimization, but I let that up to you to do ;-)
Use bigDEcimal and set the scale giving the number of decimals you need
final BigDecimal a = new BigDecimal(1.07522);
final BigDecimal b = new BigDecimal(1.0752);
final BigDecimal result = a.subtract(b);
int newScale = 10; //10 decimals
System.out.println(result.setScale(newScale, BigDecimal.ROUND_UP));
BigDecimal decimal = new BigDecimal(1.07522);
BigDecimal decimal1 = new BigDecimal(1.0752);
System.out.println(decimal.subtract(decimal1).setScale(5, RoundingMode.DOWN));
BigDecimal is the way to go, but why is the ROUND_MULTIPLIER a double value if you cast it to int anyways. Maybe that is where you get your rounding issues from? Give it a spin with an int-multiplier :)
Edit: using setScale() setting a proper rounding mode is usually a better choice, but you insist on using the multiplier, right?
I have tried the following code but it is not working in a particular case.
Eg: Suppose, I have a double value=2.5045 and i want it to be rounded off upto two decimal places using the below code.After rounding off, i get the answer as 2.5. But I want the answer to be 2.50 instead. In this case,zero is trimmed off. Is there any way to retain the zero so as to get the desired answer as 2.50 after rounding off.
private static DecimalFormat twoDForm = new DecimalFormat("#.##");
public static double roundTwoDecimals(double amount) {
return Double.valueOf(twoDForm.format(amount));
}
try this pattern
new DecimalFormat("0.00");
but this will change only formatting, double cannot hold number of digits after decimal poin, try BigDecimal
BigDecimal bd = new BigDecimal(2.5045).setScale(2, RoundingMode.HALF_UP);
Look at the documentation for DecimalFormat. For # it says:
Digit, zero shows as absent
0 is probably what you want:
Digit
So what you are looking for is either "0.00" or "#.00" as a format string, depending on whether you want the first digit before the period, to be visible in case the numbers absolute value is smalle than 0.
Try this
DecimalFormat format = new DecimalFormat("#");
format.setMinimumFractionDigits(2);
answer.setText(format.format(data2));
Try This
double d = 4.85999999999;
long l = (int)Math.round(d * 100); // truncates
d = l / 100.0;
You are returning a double. But double or Double are objects representing a number and don't carry any formatting information. Ìf you need to output two decimal places the point to do this is when you convert your double to a String.
use # if you want to ignore 0
new DecimalFormat("###,#0.00").format(d)
There is another way to achieve this . I have already posted answer in post
will just answer again here. As we will require rounding off values many times .
public class RoundingNumbers {
public static void main(String args[]){
double number = 2.5045;
int decimalsToConsider = 2;
BigDecimal bigDecimal = new BigDecimal(number);
BigDecimal roundedWithScale = bigDecimal.setScale(decimalsToConsider, BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with setting scale = "+roundedWithScale);
bigDecimal = new BigDecimal(number);
BigDecimal roundedValueWithDivideLogic = bigDecimal.divide(BigDecimal.ONE,decimalsToConsider,BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with Dividing by one = "+roundedValueWithDivideLogic);
}
}
Output we will get is
Rounded value with setting scale = 2.50
Rounded value with Dividing by one = 2.50
double kilobytes = 1205.6358;
double newKB = Math.round(kilobytes*100.0)/100.0;
DecimalFormat df = new DecimalFormat("###.##");
System.out.println("kilobytes (DecimalFormat) : " + df.format(kilobytes));
Try this if u are still getting the above problem
i have a function that calculates data that creates a BigDecimal format variable and im trying to round up or down accordingly with the results. For instance:
16.543242123 should be 16.5
3.35 should be 3.4
6.3456 should be 6.3
and so on, if the 3rd digit is equal to 5 or above to round up the 2nd digit, if its equal to 4 and below, to remove the 3rd digit. This does not absolutely need to be BigDecimal, i can figure out converting the numbers after i manage to do the rounds up.
Thanks in advance.
This should do it:
BigDecimal bg1 = new BigDecimal(16.543242123);
bg1 = bg1.setScale(1, BigDecimal.ROUND_HALF_EVEN);
System.out.println(bg1.toString()); //16.5
BigDecimal bg2 = new BigDecimal(3.35);
bg2 = bg2.setScale(1, BigDecimal.ROUND_HALF_EVEN);
System.out.println(bg2.toString()); //3.4
BigDecimal bg3 = new BigDecimal(6.3456);
bg3 = bg3.setScale(1, BigDecimal.ROUND_HALF_EVEN);
System.out.println(bg3.toString()); //6.3
BigDecimal bd = new BigDecimal("16.553242123");
BigDecimal format = bd.setScale(1, RoundingMode.HALF_UP);