LinearSpline3d (Artisynth API documentation)

java.lang.Object
- maspack.interpolation.LinearSpline3d

All Implemented Interfaces:

java.lang.Iterable<LinearSpline3d.Knot>, Scannable
```
public class LinearSpline3d
extends java.lang.Object
implements Scannable, java.lang.Iterable<LinearSpline3d.Knot>
```
Implements three dimensional linear spline interpolation. The spline is defined by a sequence of knots delimiting the boundaries between linear interpolation segements.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class LinearSpline3d.Knot

Nested Classes
Modifier and Type	Class and Description
`static class`	`LinearSpline3d.Knot`

Constructor Summary

Constructors
Constructor and Description
`LinearSpline3d()` Creates a empty spline
`LinearSpline3d(java.util.ArrayList<? extends Vector3d> xVals, java.util.ArrayList<Vector3d> dxdsVals)` Creates a spline from a set of values, withthe interval between each knot point assumed to have a length of 1.
`LinearSpline3d(double[] sVals, java.util.ArrayList<? extends Vector3d> xVals)` Creates a spline from data containing the values of s and x at each knot point.
`LinearSpline3d(LinearSpline3d spline)` Creates a spline from a copy of an existing one.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`LinearSpline3d.Knot`	`addKnot(double s, Vector3d x)` Adds another knot point to this spline at a specified s coordinate.
`void`	`clearKnots()` Removes all knots from from this spline.
`LinearSpline3d`	`copy()` Creates a copy of this spline.
`boolean`	`equals(LinearSpline3d spline)` Queries whether this spline is equal to another spline.
`Vector3d`	`eval(double s)` Evaluates the value of this spline for a specific parameter value.
`Vector3d`	`eval(double s, IntHolder lastIdx)` Evaluates the value of this spline for a specific parameter value.
`Vector3d`	`evalDx(double s)` Evaluates the derivative (with respect to the parameter) of this spline for a specific parameter value.
`Vector3d`	`evalDx(double s, IntHolder lastIdx)` Evaluates the derivative (with respect to the parameter) of this spline for a specific parameter value.
`LinearSpline3d.Knot`	`getFirstKnot()` Returns the first knot in this spline, or `null` if there are no knots.
`LinearSpline3d.Knot`	`getKnot(int idx)` Returns the `idx`-th knot in this spline.
`LinearSpline3d.Knot`	`getLastKnot()` Returns the last knot in this spline, or `null` if there are no knots.
`LinearSpline3d.Knot`	`getNextKnot(double s)` Find the knot immediately following s.
`LinearSpline3d.Knot`	`getPreceedingKnot(double s)` Find the knot immediately preceeding s.
`LinearSpline3d.Knot`	`getPreceedingKnot(double s, IntHolder lastIdx)` Find the knot immediately preceeding s.
`double`	`getS0()` Returns the start value of the parameter controlling this spline.
`double`	`getSLast()` Returns the last value of the parameter controlling this spline.
`double`	`getSLength()` Returns the length of the parameter interval controlling this spline.
`double[]`	`getSValues()` Returns an array giving the values of s at each knot.
`boolean`	`isWritable()` Returns `true` if this component should in fact be written to secondary storage.
`java.util.Iterator<LinearSpline3d.Knot>`	`iterator()` Returns an iterator for the knots in this spline.
`int`	`numKnots()` Returns the number of knots in this spline.
`boolean`	`removeKnot(LinearSpline3d.Knot knot)` Removes a knot from this spline.
`void`	`scan(ReaderTokenizer rtok, java.lang.Object ref)` Scans this spline from a ReaderTokenizer.
`void`	`set(double[] sVals, java.util.ArrayList<? extends Vector3d> xVals)` Sets this spline from specified values of s and x at each knot point.
`void`	`set(LinearSpline3d spline)` Sets this spline to be a copy of another spline.
`<T extends Vector3d> void`	`setUsingDistance(java.util.ArrayList<T> xVals)` Sets this spline from a specified set of values, using the distance between each value as the interpolating parameter.
`void`	`write(java.io.PrintWriter pw, NumberFormat fmt, java.lang.Object ref)` Writes a text description of this spline to a PrintWriter.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Constructor Detail
  - LinearSpline3d
```
public LinearSpline3d()
```
    Creates a empty spline
  - LinearSpline3d
```
public LinearSpline3d(java.util.ArrayList<? extends Vector3d> xVals,
                      java.util.ArrayList<Vector3d> dxdsVals)
```
    Creates a spline from a set of values, withthe interval between each knot point assumed to have a length of 1.
    
    Parameters:
    
    xVals - x values for each knot point
    
    dxdsVals - dxds values for each knot point
  - LinearSpline3d
```
public LinearSpline3d(double[] sVals,
                      java.util.ArrayList<? extends Vector3d> xVals)
```
    Creates a spline from data containing the values of s and x at each knot point. The values of s should be in strictly ascending order.
    
    Parameters:
    
    sVals - s values at each knot point
    
    xVals - x values for each knot point
  - LinearSpline3d
```
public LinearSpline3d(LinearSpline3d spline)
```
    Creates a spline from a copy of an existing one.
    
    Parameters:
    
    spline - spline to copy
- Method Detail
  - set
```
public void set(double[] sVals,
                java.util.ArrayList<? extends Vector3d> xVals)
```
    Sets this spline from specified values of s and x at each knot point. The values of s should be in strictly ascending order.
    
    Parameters:
    
    sVals - s values at each knot point
    
    xVals - x values for each knot point
  - setUsingDistance
```
public <T extends Vector3d> void setUsingDistance(java.util.ArrayList<T> xVals)
```
    Sets this spline from a specified set of values, using the distance between each value as the interpolating parameter. Adjacent values are ignored.
    
    Parameters:
    
    xVals - x values for each knot point
  - getSValues
```
public double[] getSValues()
```
    Returns an array giving the values of s at each knot.
    
    Returns:
    
    array of s values
  - addKnot
```
public LinearSpline3d.Knot addKnot(double s,
                                   Vector3d x)
```
    Adds another knot point to this spline at a specified s coordinate.
    
    Parameters:
    
    s - parameter value at which the knot should be added
    
    x - value at the knot
  - removeKnot
```
public boolean removeKnot(LinearSpline3d.Knot knot)
```
    Removes a knot from this spline.
    
    Parameters:
    
    knot - knot to remove
  - clearKnots
```
public void clearKnots()
```
    Removes all knots from from this spline.
  - getPreceedingKnot
```
public LinearSpline3d.Knot getPreceedingKnot(double s)
```
    Find the knot immediately preceeding s. Specifically, find the nearest knot for which knot.getS0() <= s. If no such knot exists, null is returned.
    
    Parameters:
    
    s - value for which preceeding knot is sought
  - getPreceedingKnot
```
public LinearSpline3d.Knot getPreceedingKnot(double s,
                                             IntHolder lastIdx)
```
    Find the knot immediately preceeding s. Specifically, find the nearest knot for which knot.getS0() <= s. If no such knot exists, null is returned.
    The optional parameter lastIdx, described below, can be used to significantly reduce the search speed when queries are made with increasing values of s.
    
    Parameters:
    
    s - value for which preceeding knot is sought
    
    lastIdx - if non-null, specifies a index value giving a hint on where to start the knot search. On output, this value is set to the index of the returned knot, or -1 if no knot is found.
  - getNextKnot
```
public LinearSpline3d.Knot getNextKnot(double s)
```
    Find the knot immediately following s. Specifically, find the nearest knot for which knot.x0 > s. If no such knot exists, null is returned.
    
    Parameters:
    
    s - value for which next knot is sought
  - eval
```
public Vector3d eval(double s)
```
    Evaluates the value of this spline for a specific parameter value. For parameter values outside the knot range, the value is lineraly extrapolated based on derivatives at the first or last knots. An empty spline evaluates to 0.
    
    Parameters:
    
    s - parameter for which the value should be computed
  - eval
```
public Vector3d eval(double s,
                     IntHolder lastIdx)
```
    Evaluates the value of this spline for a specific parameter value. For parameter values outside the knot range, the value is lineraly extrapolated based on derivatives at the first or last knots. An empty spline evaluates to 0.
    The optional parameter lastIdx, described below, can be used to significantly reduce the search speed when queries are made with increasing values of s.
    
    Parameters:
    
    s - parameter for which the value should be computed
    
    lastIdx - if non-null, specifies a index value giving a hint on where to search for the knot preceeding s. On output, this value is set to the index of the preceeding knot, or -1 if no preceeding knot is found.
  - evalDx
```
public Vector3d evalDx(double s)
```
    Evaluates the derivative (with respect to the parameter) of this spline for a specific parameter value. For parameter values outside the knot range, the value is set to the derivative at either the first or last knot. An empty spline evaluates to 0.
    
    Parameters:
    
    s - parameter for which the derivative should be computed
  - evalDx
```
public Vector3d evalDx(double s,
                       IntHolder lastIdx)
```
    Evaluates the derivative (with respect to the parameter) of this spline for a specific parameter value. For parameter values outside the knot range, the value is set to the derivative at either the first or last knot. An empty spline evaluates to 0.
    The optional parameter lastIdx, described below, can be used to significantly reduce the search speed when queries are made with increasing values of s.
    
    Parameters:
    
    s - parameter for which the derivative should be computed
    
    lastIdx - if non-null, specifies a index value giving a hint on where to search for the knot preceeding s. On output, this value is set to the index of the preceeding knot, or -1 if no preceeding knot is found.
  - scan
```
public void scan(ReaderTokenizer rtok,
                 java.lang.Object ref)
          throws java.io.IOException
```
    Scans this spline from a ReaderTokenizer. The expected format consists of an opening square bracket, followed by 4 n numeric values giving the s and x values for each of the n knots, and terminated with a closing square bracket. Whitespace characters are ignored. For example,
```
  [  0.0
     0.0 4.0 1.0
     1.0
     0.0 5.0 1.2
  ]
 
```
    describes a spline with two knots, with s and x equal to 0, and (0, 4, 1))} for the first knot and 1 and (0, 5, 1.2) for the second knot.
    Specified by:
    
    scan in interface Scannable
    
    Parameters:
    
    rtok - Tokenizer from which to scan the spline
    
    ref - optional reference object (not used)
    
    Throws:
    
    java.io.IOException - if an I/O or formatting error occured
  - write
```
public void write(java.io.PrintWriter pw,
                  NumberFormat fmt,
                  java.lang.Object ref)
           throws java.io.IOException
```
    Writes a text description of this spline to a PrintWriter. The format is the same as that described for scan.
    
    Specified by:
    
    write in interface Scannable
    
    Parameters:
    
    pw - writer to which the spline should be written
    
    fmt - describes how the numbers should be formatted
    
    ref - optional reference object (not used)
    
    Throws:
    
    java.io.IOException - if an I/O error occured
  - isWritable
```
public boolean isWritable()
```
    Returns true if this component should in fact be written to secondary storage. This gives subclasses control over whether or not they are actually written out.
    
    Specified by:
    
    isWritable in interface Scannable
    
    Returns:
    
    true if this component should be written to secondary storage.
  - numKnots
```
public int numKnots()
```
    Returns the number of knots in this spline.
    
    Returns:
    
    number of knots
  - getKnot
```
public LinearSpline3d.Knot getKnot(int idx)
```
    Returns the idx-th knot in this spline.
    
    Parameters:
    
    idx - index of the requested knot
    
    Returns:
    
    idx-th knot
  - getFirstKnot
```
public LinearSpline3d.Knot getFirstKnot()
```
    Returns the first knot in this spline, or null if there are no knots.
    
    Returns:
    
    first knot
  - getLastKnot
```
public LinearSpline3d.Knot getLastKnot()
```
    Returns the last knot in this spline, or null if there are no knots.
    
    Returns:
    
    last knot
  - getS0
```
public double getS0()
```
    Returns the start value of the parameter controlling this spline.
    
    Returns:
    
    starting parameter value
  - getSLast
```
public double getSLast()
```
    Returns the last value of the parameter controlling this spline.
    
    Returns:
    
    last parameter value
  - getSLength
```
public double getSLength()
```
    Returns the length of the parameter interval controlling this spline.
    
    Returns:
    
    parameter interval length
  - iterator
```
public java.util.Iterator<LinearSpline3d.Knot> iterator()
```
    Returns an iterator for the knots in this spline.
    
    Specified by:
    
    iterator in interface java.lang.Iterable<LinearSpline3d.Knot>
    
    Returns:
    
    spline knot iterator
  - set
```
public void set(LinearSpline3d spline)
```
    Sets this spline to be a copy of another spline.
    
    Parameters:
    
    spline - spline to copy
  - copy
```
public LinearSpline3d copy()
```
    Creates a copy of this spline.
  - equals
```
public boolean equals(LinearSpline3d spline)
```
    Queries whether this spline is equal to another spline.
    
    Parameters:
    
    spline - spline to compare to this one
    
    Returns:
    
    true if the splines are equal

Class LinearSpline3d

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Constructor Detail

LinearSpline3d

LinearSpline3d

LinearSpline3d

LinearSpline3d

Method Detail

set

setUsingDistance

getSValues

addKnot

removeKnot

clearKnots

getPreceedingKnot

getPreceedingKnot

getNextKnot

eval

eval

evalDx

evalDx

scan

write

isWritable

numKnots

getKnot

getFirstKnot

getLastKnot

getS0

getSLast

getSLength

iterator

set

copy

equals