public class Measurement
extends java.lang.Object
implements java.lang.Comparable
A Measurement object is used for maintaining the tuple of value,
error, unit and time-stamp. The value and error are represented as doubles
and the time is measured in milliseconds since midnight, January 1, 1970 UTC.
Mathematic methods are provided that correctly calculate taking the error
into account. A runtime error will occur when two measurements are used in an
incompatible way. E.g., when a speed (m/s) is added to a distance (m). The
measurement class will correctly track changes in unit during multiplication
and division, always coercing the result to the most simple form. See
Unit for more information on the supported units.
Errors in the measurement class are absolute errors. Measurement errors should use the P95 rule. Actual values must fall in the range value +/- error 95% or more of the time.
A Measurement object is immutable in order to be easily shared.
Note: This class has a natural ordering that is inconsistent with equals. See
compareTo(Object).
| Constructor and Description |
|---|
Measurement(double value)
Create a new
Measurement object with an error of 0.0, a unit of
Unit.unity and a time of zero. |
Measurement(double value,
double error,
Unit unit)
Create a new
Measurement object with a time of zero. |
Measurement(double value,
double error,
Unit unit,
long time)
Create a new
Measurement object. |
Measurement(double value,
Unit unit)
Create a new
Measurement object with an error of 0.0 and a time
of zero. |
| Modifier and Type | Method and Description |
|---|---|
Measurement |
add(double d)
Returns a new
Measurement object that is the sum of this object
added to the specified value. |
Measurement |
add(double d,
Unit u)
Returns a new
Measurement object that is the sum of this object
added to the specified value. |
Measurement |
add(Measurement m)
Returns a new
Measurement object that is the sum of this object
added to the specified object. |
int |
compareTo(java.lang.Object obj)
Compares this object with the specified object for order.
|
Measurement |
div(double d)
Returns a new
Measurement object that is the quotient of this
object divided by the specified value. |
Measurement |
div(double d,
Unit u)
Returns a new
Measurement object that is the quotient of this
object divided by the specified value. |
Measurement |
div(Measurement m)
Returns a new
Measurement object that is the quotient of this
object divided by the specified object. |
boolean |
equals(java.lang.Object obj)
Returns whether the specified object is equal to this object.
|
double |
getError()
Returns the error of this
Measurement object. |
long |
getTime()
Returns the time at which this
Measurement object was taken. |
Unit |
getUnit()
Returns the
Unit object of this Measurement object. |
double |
getValue()
Returns the value of this
Measurement object. |
int |
hashCode()
Returns a hash code value for this object.
|
Measurement |
mul(double d)
Returns a new
Measurement object that is the product of this
object multiplied by the specified value. |
Measurement |
mul(double d,
Unit u)
Returns a new
Measurement object that is the product of this
object multiplied by the specified value. |
Measurement |
mul(Measurement m)
Returns a new
Measurement object that is the product of this
object multiplied by the specified object. |
Measurement |
sub(double d)
Returns a new
Measurement object that is the subtraction of the
specified value from this object. |
Measurement |
sub(double d,
Unit u)
Returns a new
Measurement object that is the subtraction of the
specified value from this object. |
Measurement |
sub(Measurement m)
Returns a new
Measurement object that is the subtraction of the
specified object from this object. |
java.lang.String |
toString()
Returns a
String object representing this Measurement
object. |
public Measurement(double value,
double error,
Unit unit,
long time)
Measurement object.value - The value of the Measurement.error - The error of the Measurement.unit - The Unit object in which the value is measured. If
this argument is null, then the unit will be set to
Unit.unity.time - The time measured in milliseconds since midnight, January 1,
1970 UTC.public Measurement(double value,
double error,
Unit unit)
Measurement object with a time of zero.value - The value of the Measurement.error - The error of the Measurement.unit - The Unit object in which the value is measured. If
this argument is null, then the unit will be set to
Unit.unity.public Measurement(double value,
Unit unit)
Measurement object with an error of 0.0 and a time
of zero.value - The value of the Measurement.unit - The Unit in which the value is measured. If this
argument is null, then the unit will be set to
Unit.unity.public Measurement(double value)
Measurement object with an error of 0.0, a unit of
Unit.unity and a time of zero.value - The value of the Measurement.public final double getValue()
Measurement object.Measurement object as a double.public final double getError()
Measurement object. The error is always
a positive value.Measurement as a double.public final Unit getUnit()
Unit object of this Measurement object.Unit object of this Measurement object.Unitpublic final long getTime()
Measurement object was taken. The
time is measured in milliseconds since midnight, January 1, 1970 UTC, or
zero when not defined.Measurement object was taken or
zero.public Measurement mul(Measurement m)
Measurement object that is the product of this
object multiplied by the specified object.m - The Measurement object that will be multiplied with this
object.Measurement that is the product of this object
multiplied by the specified object. The error and unit of the new
object are computed. The time of the new object is set to the
time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be multiplied.Unitpublic Measurement mul(double d, Unit u)
Measurement object that is the product of this
object multiplied by the specified value.d - The value that will be multiplied with this object.u - The Unit of the specified value.Measurement object that is the product of this
object multiplied by the specified value. The error and unit of
the new object are computed. The time of the new object is set to
the time of this object.java.lang.ArithmeticException - If the units of this object and the specified
value cannot be multiplied.Unitpublic Measurement mul(double d)
Measurement object that is the product of this
object multiplied by the specified value.d - The value that will be multiplied with this object.Measurement object that is the product of this
object multiplied by the specified value. The error of the new
object is computed. The unit and time of the new object is set to
the unit and time of this object.public Measurement div(Measurement m)
Measurement object that is the quotient of this
object divided by the specified object.m - The Measurement object that will be the divisor of this
object.Measurement object that is the quotient of this
object divided by the specified object. The error and unit of the
new object are computed. The time of the new object is set to the
time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be divided.Unitpublic Measurement div(double d, Unit u)
Measurement object that is the quotient of this
object divided by the specified value.d - The value that will be the divisor of this object.u - The Unit object of the specified value.Measurement that is the quotient of this object
divided by the specified value. The error and unit of the new
object are computed. The time of the new object is set to the
time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be divided.Unitpublic Measurement div(double d)
Measurement object that is the quotient of this
object divided by the specified value.d - The value that will be the divisor of this object.Measurement object that is the quotient of this
object divided by the specified value. The error of the new
object is computed. The unit and time of the new object is set to
the Unit and time of this object.public Measurement add(Measurement m)
Measurement object that is the sum of this object
added to the specified object.
The error and unit of the new object are computed. The time of the new
object is set to the time of this object.m - The Measurement object that will be added with this
object.Measurement object that is the sum of this and m.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be added.Unitpublic Measurement add(double d, Unit u)
Measurement object that is the sum of this object
added to the specified value.d - The value that will be added with this object.u - The Unit object of the specified value.Measurement object that is the sum of this object
added to the specified value. The unit of the new object is
computed. The error and time of the new object is set to the
error and time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified value cannot be added.Unitpublic Measurement add(double d)
Measurement object that is the sum of this object
added to the specified value.d - The value that will be added with this object.Measurement object that is the sum of this object
added to the specified value. The error, unit, and time of the
new object is set to the error, Unit and time of this
object.public Measurement sub(Measurement m)
Measurement object that is the subtraction of the
specified object from this object.m - The Measurement object that will be subtracted from this
object.Measurement object that is the subtraction of the
specified object from this object. The error and unit of the new
object are computed. The time of the new object is set to the
time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be subtracted.Unitpublic Measurement sub(double d, Unit u)
Measurement object that is the subtraction of the
specified value from this object.d - The value that will be subtracted from this object.u - The Unit object of the specified value.Measurement object that is the subtraction of the
specified value from this object. The unit of the new object is
computed. The error and time of the new object is set to the
error and time of this object.java.lang.ArithmeticException - If the Unit objects of this object
and the specified object cannot be subtracted.Unitpublic Measurement sub(double d)
Measurement object that is the subtraction of the
specified value from this object.d - The value that will be subtracted from this object.Measurement object that is the subtraction of the
specified value from this object. The error, unit and time of the
new object is set to the error, Unit object and time of
this object.public java.lang.String toString()
String object representing this Measurement
object.toString in class java.lang.ObjectString object representing this Measurement
object.public int compareTo(java.lang.Object obj)
Note: This class has a natural ordering that is inconsistent with equals.
For this method, another Measurement object is considered equal
if there is some x such that
getValue() - getError() <= x <= getValue() + getError()for both
Measurement objects being compared.compareTo in interface java.lang.Comparableobj - The object to be compared.java.lang.ClassCastException - If the specified object is not of type
Measurement.java.lang.ArithmeticException - If the unit of the specified
Measurement object is not equal to the Unit
object of this object.public int hashCode()
hashCode in class java.lang.Objectpublic boolean equals(java.lang.Object obj)
Measurement objects are equal if they have same value, error and
Unit.
Note: This class has a natural ordering that is inconsistent with equals.
See compareTo(Object).
equals in class java.lang.Objectobj - The object to compare with this object.true if this object is equal to the specified object;
false otherwise.