## org.jfree.data.general
Interface HeatMapDataset

All Known Implementing Classes:
  DefaultHeatMapDataset

    public interface HeatMapDataset

A dataset that represents a rectangular grid of (x, y, z) values. The x and y values appear at regular intervals in the dataset, while the z-values can take any value (including `null` for unknown values).

Since:
  1.0.13

Method Summary
`double` `getMaximumXValue()` Returns the highest x-value represented in this dataset.
`double` `getMaximumYValue()` Returns the highest y-value represented in this dataset.
`double` `getMinimumXValue()` Returns the lowest x-value represented in this dataset.
`double` `getMinimumYValue()` Returns the lowest y-value represented in this dataset.
`int` `getXSampleCount()` Returns the number of x values across the width of the dataset.
`double` `getXValue(int xIndex)` A convenience method that returns the x-value for the given index.
`int` `getYSampleCount()` Returns the number of y values (or samples) for the dataset.
`double` `getYValue(int yIndex)` A convenience method that returns the y-value for the given index.
`java.lang.Number` `getZ(int xIndex, int yIndex)` Returns the z-value at the specified sample position in the dataset.
`double` `getZValue(int xIndex, int yIndex)` Returns the z-value at the specified sample position in the dataset.

Method Detail

### getXSampleCount

    int getXSampleCount()

  Returns the number of x values across the width of the dataset. The values are evenly spaced between `getMinimumXValue()` and `getMaximumXValue()`.

  Returns:
    The number of x-values (always > 0).

### getYSampleCount

    int getYSampleCount()

  Returns the number of y values (or samples) for the dataset. The values are evenly spaced between `getMinimumYValue()` and `getMaximumYValue()`.

  Returns:
    The number of y-values (always > 0).

### getMinimumXValue

    double getMinimumXValue()

  Returns the lowest x-value represented in this dataset. A requirement of this interface is that this method must never return infinite or Double.NAN values.

  Returns:
    The lowest x-value represented in this dataset.

### getMaximumXValue

    double getMaximumXValue()

  Returns the highest x-value represented in this dataset. A requirement of this interface is that this method must never return infinite or Double.NAN values.

  Returns:
    The highest x-value represented in this dataset.

### getMinimumYValue

    double getMinimumYValue()

  Returns the lowest y-value represented in this dataset. A requirement of this interface is that this method must never return infinite or Double.NAN values.

  Returns:
    The lowest y-value represented in this dataset.

### getMaximumYValue

    double getMaximumYValue()

  Returns the highest y-value represented in this dataset. A requirement of this interface is that this method must never return infinite or Double.NAN values.

  Returns:
    The highest y-value represented in this dataset.

### getXValue

    double getXValue(int xIndex)

  A convenience method that returns the x-value for the given index.

  Parameters:
    `xIndex` - the xIndex.
  Returns:
    The x-value.

### getYValue

    double getYValue(int yIndex)

  A convenience method that returns the y-value for the given index.

  Parameters:
    `yIndex` - the yIndex.
  Returns:
    The y-value.

### getZValue

    double getZValue(int xIndex,
                     int yIndex)

  Returns the z-value at the specified sample position in the dataset. For a missing or unknown value, this method should return Double.NAN.

  Parameters:
    `xIndex` - the position of the x sample in the dataset.
    `yIndex` - the position of the y sample in the dataset.
  Returns:
    The z-value.

### getZ

    java.lang.Number getZ(int xIndex,
                          int yIndex)

  Returns the z-value at the specified sample position in the dataset. This method can return `null` to indicate a missing/unknown value.
  Bear in mind that the class implementing this interface may store its data using primitives rather than objects, so calling this method may require a new `Number` object to be allocated... for this reason, it is generally preferable to use the `getZValue(int, int)` method unless you *know* that the dataset implementation stores the z-values using objects.

  Parameters:
    `xIndex` - the position of the x sample in the dataset.
    `yIndex` - the position of the y sample in the dataset.
  Returns:
    The z-value (possibly `null`).