Class DVector

# Class DVector

```java.lang.Object
|
+----DVector
```

class DVector
extends Object
A DVector represents a vector in R2; each coordinate is a double.
DVector()
Create a new DVector with unspecified coordinates (actually I think the coords are initialized to 0, but don't count on this).
DVector(double, double)
Create a new DVector with given coordinates.
array(double, double)
Construct an array of DVectors; the array method takes 2,4,6, or 8 doubles, and returns an array of 1,2,3, or 4 DVectors, respectively.
array(double, double, double, double)
array(double, double, double, double, double, double)
array(double, double, double, double, double, double, double, double)
aString(DVector[])
Convert an array of DVectors to a string.
copy()
Return a copy of this vector.
dot(DVector)
Return the dot product of this vector with another one.
length()
Return the length (magnitude) of this DVector (sqrt(x^2 + y^2))
negate()
Multiply this vector by -1.
scale(double)
Multiply this vector by the scalar s.
toString()
Convert a DVector to a String
DVector
```  public DVector(double x,
double y)
```
Create a new DVector with given coordinates.
DVector
```  public DVector()
```
Create a new DVector with unspecified coordinates (actually I think the coords are initialized to 0, but don't count on this).
toString
```  public String toString()
```
Convert a DVector to a String
Overrides:
toString in class Object
length
```  public double length()
```
Return the length (magnitude) of this DVector (sqrt(x^2 + y^2))
negate
```  public void negate()
```
Multiply this vector by -1.
scale
```  public void scale(double s)
```
Multiply this vector by the scalar s.
dot
```  public double dot(DVector v)
```
Return the dot product of this vector with another one.
copy
```  public DVector copy()
```
Return a copy of this vector.
array
```  public static DVector[] array(double x0,
double y0)
```
Construct an array of DVectors; the array method takes 2,4,6, or 8 doubles, and returns an array of 1,2,3, or 4 DVectors, respectively.
array
```  public static DVector[] array(double x0,
double y0,
double x1,
double y1)
```
array
```  public static DVector[] array(double x0,
double y0,
double x1,
double y1,
double x2,
double y2)
```
array
```  public static DVector[] array(double x0,
double y0,
double x1,
double y1,
double x2,
double y2,
double x3,
double y3)
```
aString
```  public static String aString(DVector v[])
```
Convert an array of DVectors to a string.