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The Basics
Property arrays are properties and/or data items like PeData.Y,
PeString.SubsetLabels, PeColor.PointColors,
and many others that have multiple values defined by one or two indices.
These property arrays are dynamic in that they grow as you increase the
indices used to set items. Some property arrays have default elements
defined and others are empty by default.
Some examples of property arrays with default elements are PePlot.SubsetLineTypes,
PePlot.SubsetPointTypes, and
PeColor.SubsetColors.
Some examples of property arrays empty by default are PeData.RandomSubsetsToGraph,
PeLegend.SubsetsToLegend, and
PeGrid.MultiAxesSubsets.
The Visual Basic syntax for setting property arrays is like...
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Pego1.PeData.Y(nSubetIndex,
nPointIndex) = fDataValue |
The C# syntax for setting property arrays is like...
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Pego1.PeData.Y[nSubetIndex,
nPointIndex] = fDataValue; |
Similar syntax is used with one dimensional property arrays and when
getting/retrieving values.
It is important to realize that a property array has a size and this
size is often used to control image construction. If you are providing
some form of user interface or report procedure, you may be continuously
manipulating property arrays. If they grow dynamically, you also need
a way to shrink or empty the property array. This can be accomplished
using the Clear method. For example,
RandomSubsetsToGraph is a common property array that needs to be emptied
or resized. The following code shows how to empty this property array.
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Pego1.PeData.RandomSubsetsToGraph.Clear() |
You can determine the total size of a property array with the Length() method.
Also note that PeFunction.Reset() will empty
the control of all property settings and revert the object to its default
state. This is easier and the recommended approach when you need to reset
the state of the object due to repeatedly changing the object.
Beyond the Basics
For most of you, the basic information above is all you'll ever need
to work with data within ProEssentials. The
technology behind property arrays is known as Indexers.
These are
special .NET classes to facilitate working with dynamic lists using common
array nomenclature.
ProEssentials defines some common Indexers
to work with different types of property arrays. You will never allocate
these classes yourself, but inherently use them as embedded features.
You may
see mention of these classes when working with ProEssentials. Just note
they are internal mechanisms to facilitate working with arrays. The more
commonly used classes include...
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OneDimensionalFloatArray |
TwoDimensionalFloatArray |
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OneDimensionalDoubleArray |
TwoDimensionalDoubleArray |
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OneDimensionalStringArray |
TwoDimensionalStringArray |
The Indexers classes above also contain a few more methods which you
may find useful...
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GetLength(int dimension) |
Determines the size
of individual dimensions for two dimensional arrays.
Possible dimension settings are:
- 0, gets size of first dimension.
- 1, gets size of the second dimension. |
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Clear(int newSize) |
Sets the new size
of a property array. Truncating
its size and losing all elements past newSize. |
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Initialize(float dataValue) |
Fills array with
the provided data value. Useful
to initialize array with a user defined null
data value. If needed, the size of array should first be set by simply
setting the last element in the array. |
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FastCopyFrom(float[,] source) |
Available only with data property arrays. Copies elements from a source
array into this array. The size of the dimensions must be PeData.Subsets
by PeData.Points. This
methods calls ProEssentials.Api.PEvset which
block copies the source bytes directly into the chart. |
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CopyFrom(float[,] source) |
Available only with data property arrays. Copies elements from a source
array into this array. The size of the dimensions must be PeData.Subsets
by PeData.Points. |
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float[,] Copy() |
Available only with data property arrays. Copies this array to another
array. The size of the dimensions will be PeData.Subsets by PeData.Points. |
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int BindData(IEnumerable source,
int
startingSubsetIndex,
int
startingPointIndex) |
Available only with data property arrays. Loads data from a DataReader
or DataView source. This
method does not clear existing data or alter PeData.Subsets and PeData.Points.
This method
will fill this array with data up-to an amount defined by PeData.Subsets
and PeData.Points. Data
is loaded at indices starting with startingSubsetIndex
and startingPointIndex. Multiple
subsets of data are read in and allocated by their sequence in column.
The return value is the number of records set. |
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