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Class edu.wpi.mqp.graphics.jviz.Data

java.lang.Object
   |
   +----edu.wpi.mqp.graphics.jviz.Data

public class Data

extends Object

implements Cloneable

Version:

1.0, created 21 OCT 1997

Author:

Matthew C. Jucius

capacity

dataPoints

dimensionData

numDataPoints

Data()

This constructor for Data initilizes the public variables.

addDataPoint(double[])

This method, addDatapoint, takes a DataPoint object as an argument and adds it to the end of the dataPoints array.

addDimension(DimensionalData)

Will add a DimensionalData object to the end the dimensionData vector.

clone()

This allows this class to be cloned

getActiveDataPoint(int)

This method will return an exact sized double array with the values of a data point that are within active dimensions.

getActiveDimensionData(int)

This method is another getActive***() method.

getActiveDimensions()

This function, getActiveDimensions, returns an array of indicies to the dimensions which are active.

getAllActiveDataPoints()

This method is a convience function, but it is quite inefficient.

getDataPoint(int)

This method will return a double array of the data point at the specified specified index into the data points array

getDimensionData(int)

Returns the specified dimensions

getNumActiveDimensions()

This method, getNumActiveDimensions, returns the number of active dimensions in the data set.

getNumDataPoints()

Gets the number of data points in the dataPoints array.

getNumDimensions()

Returns the total number of dimensions whether they are active or not.

 protected int numDataPoints

 protected int capacity

 protected double dataPoints[][]

 protected Vector dimensionData

 public Data()

This constructor for Data initilizes the public variables.

 public int addDataPoint(double dataSet[])

This method, addDatapoint, takes a DataPoint object as an argument and adds it to the end of the dataPoints array. This two-dimensional array grows incrementally. When the capacity has been reached, a newer, larger array is instantiated and the contents of the old are transferred into the new array. Each step in growth increases capacity by 1024 data points.

Parameters:

dataSet - an array of doubles that contain all the values for a data point.

Returns:

the index of the point that was added to the array

 public double[] getDataPoint(int dataPointIndex)

This method will return a double array of the data point at the specified specified index into the data points array

Parameters:

dataValueIndex - the index of the object to return

Returns:

double array of entire point

 public double[][] getAllActiveDataPoints()

This method is a convience function, but it is quite inefficient. It will return a huge array of all the data points, but only include the values for the active dimensions. If first determines what the active dimensions are, instatitates a huge array of doubles, and then copies the associated values into the new array. Finally, it returns the array.

Returns:

activeDataPoints two-dimensional array of doubles

 public int[] getActiveDimensions()

This function, getActiveDimensions, returns an array of indicies to the dimensions which are active. The values for the data points are stored in a two dimensional array. If a dimension is deactivated, this object must be able to present an interface to the outside world that hides the details of this. That is what the getActive***() methods are for. They will return the values for a virtual data set that changes whenever a dimension is activated or deactivated. They admittedly use a horrible naming scheme and the implementation is much more inefficient, but they do work. This function provides a way to map between the numbering scheme of the virtual data set with deactivated dimensions and the real data set. If this function returns an array with values: 0 2 3 4 5 and the real data set has 6 dimensions, you would know that, in the real data set, column 1 has been deactivated. This also means dimension 1 has been deactivated. You can determine, using array.lenth, that there are 5 active dimensions. The concept may be confusing, but the numbers line up quite nicely when the getActive***() methods are used consistently One important note for future work, if this function could be implemented more efficiently, many of the getActive***() methods would becore much more efficient. This method can be a bottleneck. If there was a way to keep track of each activation and deactivation of a dimension within this class, a check through all the dimensions would not have to be made each time this method was called. If all dimensions activation and deactivation was done through this class, it might be possible, but that is not how it is currently being done in JViz.

Returns:

activeDimentions int array of indices of active dimensions in the real data set.

 public int getNumActiveDimensions()

This method, getNumActiveDimensions, returns the number of active dimensions in the data set. If you have already made a call to getActiveDimenions, it would be more efficient to call returnedArray.length on the returned array rather than calling this method, but you will get the same answer either way.

Returns:

numActiveDimenions as an int

 public DimensionalData getActiveDimensionData(int index)

This method is another getActive***() method. It returns a DimensionalData object based in the index passed to it. The index is the nth active dimenions. For example, if dimensions 0,1,3, and 4 are active, a call with index value of 2 will return the dimensional data object for the 3rd dimension.

Parameters:

index - nth active dimension to return DimansionalData of.

Returns:

DimensionalData object of the specified active index

 public double[] getActiveDataPoint(int index)

This method will return an exact sized double array with the values of a data point that are within active dimensions. This method is not as efficient as getDatapoint(). Each call to this function makes a call to getActiveDimensions(). It may be beneficial to deal with active dimensions at a different level if efficiency is a concern. A single call to getActiveDimensions() and calls to getDataPoint() and checking only the active dimensions could improve efficiency since there is only one call to getActiveDimensions().

Parameters:

index - index of point to return.

Returns:

activePoint double array of length numActiveDimensions.

 public int getNumDataPoints()

Gets the number of data points in the dataPoints array.

Returns:

number of data points in numDataPoints vector

 public int getNumDimensions()

Returns the total number of dimensions whether they are active or not.

Returns:

value of numDimensions

 public DimensionalData getDimensionData(int index)

Returns the specified dimensions

Parameters:

index - index in vector of the dimension

Returns:

specified DimensionalData object

 public int addDimension(DimensionalData newDimensionData)

Will add a DimensionalData object to the end the dimensionData vector. Each element in the dimensionData vector represents a different dimension and contains information such as its name, cardinality, active state, and more.

Parameters:

newDimensionData - object to add to vector

Returns:

index in Vector where object was placed.

 public Object clone()

This allows this class to be cloned

Returns:

clone of this object; null if error occurred

Overrides:

clone in class Object

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