public class DoubleSummaryStatistics extends Objectimplements DoubleConsumer
This class is designed to work with (though does not require) streams. For example, you can compute summary statistics on a stream of doubles with:
DoubleSummaryStatistics stats = doubleStream.collect(DoubleSummaryStatistics::new, DoubleSummaryStatistics::accept, DoubleSummaryStatistics::combine);
DoubleSummaryStatistics
can be used as a reduction target for a stream. For example:
DoubleSummaryStatistics stats = people.stream() .collect(Collectors.summarizingDouble(Person::getWeight));
This computes, in a single pass, the count of people, as well as the minimum, maximum, sum, and average of their weights.
Constructor and Description 

DoubleSummaryStatistics()
Construct an empty instance with zero count, zero sum,
Double.POSITIVE_INFINITY min,
Double.NEGATIVE_INFINITY max and zero average.

Modifier and Type  Method and Description 

void 
accept(double value)
Records another value into the summary information.

void 
combine(DoubleSummaryStatistics
Combines the state of another
DoubleSummaryStatistics into this one.

double 
getAverage()
Returns the arithmetic mean of values recorded, or zero if no values have been recorded.

long 
getCount()
Return the count of values recorded.

double 
getMax()
Returns the maximum recorded value,
Double.NaN if any recorded value was NaN or
Double.NEGATIVE_INFINITY if no values were recorded.

double 
getMin()
Returns the minimum recorded value,
Double.NaN if any recorded value was NaN or
Double.POSITIVE_INFINITY if no values were recorded.

double 
getSum()
Returns the sum of values recorded, or zero if no values have been recorded.

String 
toString()
Returns a string representation of the object.

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
andThen
public DoubleSummaryStatistics()
Double.POSITIVE_INFINITY
min,
Double.NEGATIVE_INFINITY
max and zero average.
public void accept(double value)
accept
in interface
DoubleConsumer
value
 the input value
public void combine(DoubleSummaryStatisticsother)
DoubleSummaryStatistics
into this one.
other
 another
DoubleSummaryStatistics
NullPointerException
 if
other
is null
public final long getCount()
public final double getSum()
The value of a floatingpoint sum is a function both of the input values as well as the order of addition operations. The order of addition operations of this method is intentionally not defined to allow for implementation flexibility to improve the speed and accuracy of the computed result. In particular, this method may be implemented using compensated summation or other technique to reduce the error bound in the numerical sum compared to a simple summation of double
values.
public final double getMin()
Double.NaN
if any recorded value was NaN or
Double.POSITIVE_INFINITY
if no values were recorded. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero.
Double.NaN
if any recorded value was NaN or
Double.POSITIVE_INFINITY
if no values were recorded
public final double getMax()
Double.NaN
if any recorded value was NaN or
Double.NEGATIVE_INFINITY
if no values were recorded. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero.
Double.NaN
if any recorded value was NaN or
Double.NEGATIVE_INFINITY
if no values were recorded
public final double getAverage()
The average returned can vary depending upon the order in which values are recorded. This method may be implemented using compensated summation or other technique to reduce the error bound in the numerical sum
used to compute the average.
public StringtoString()
toString
method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the object is an instance, the atsign character `@
', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:
Returns a nonempty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.getClass().getName() + '@' + Integer.toHexString(hashCode())