iOS Charting Documentation - SciChart iOS Charts SDK v3.x

DataSeries Types in SciChart

SciChart features a proprietary DataSeries API, which internally uses the fastest possible data-structures to allow fast manipulation of data bound to charts.

Our DataSeries are highly optimized data-structures for indexing, searching and iterating over data, enabling SciChart to achieve its record performance!

The following DataSeries types exist in SciChart iOS.

NOTE: Allowable types in SciChart include NSDate, Int64, Int32, Int16, Byte, Double, Float.

Data Series Type Series Applicable
SCIXyDataSeries - stores X and Y Data SCIFastLineRenderableSeries, SCIFastMountainRenderableSeries, SCIXyScatterRenderableSeries, SCIFastColumnRenderableSeries, SCIFastImpulseRenderableSeries and SCIFastFixedErrorBarsRenderableSeries
SCIXyyDataSeries - stores X, Y and Y1 Data SCIFastBandRenderableSeries (required). Can also apply to SCIFastLineRenderableSeries, SCIFastMountainRenderableSeries, SCIXyScatterRenderableSeries, SCIFastColumnRenderableSeries, SCIFastImpulseRenderableSeries and SCIFastFixedErrorBarsRenderableSeries. In this case only the X and Y value are chosen
SCIXyzDataSeries - stores X, Y and Z Data SCIFastBubbleRenderableSeries (required). Can also apply to SCIFastLineRenderableSeries, SCIFastMountainRenderableSeries, SCIXyScatterRenderableSeries, SCIFastColumnRenderableSeries, SCIFastImpulseRenderableSeries and SCIFastFixedErrorBarsRenderableSeries. In this case only the X and Z value are chosen
SCIHlDataSeries - stores X, Y, High and Low Data SCIFastErrorBarsRenderableSeries (required). Can also apply to SCIFastLineRenderableSeries, SCIFastMountainRenderableSeries, SCIXyScatterRenderableSeries, SCIFastColumnRenderableSeries, SCIFastImpulseRenderableSeries and SCIFastFixedErrorBarsRenderableSeries. In this case only the X and Y values are chosen
SCIOhlcDataSeries - stores X, Open, High, Low and Close Data SCIFastCandlestickRenderableSeries or SCIFastOhlcRenderableSeries (required). Can also apply to SCIFastLineRenderableSeries, SCIFastMountainRenderableSeries, SCIXyScatterRenderableSeries, SCIFastColumnRenderableSeries, SCIFastImpulseRenderableSeries and SCIFastFixedErrorBarsRenderableSeries. In this case only the X and Close values are chosen
SCIUniformHeatmapDataSeries - stores TY values as array of TY, and TX, TZ values are computed from cell index, Start and Step values SCIFastUniformHeatmapRenderableSeries (required). This DataSeries type is not applicable to any other RenderableSeries

Manipulating DataSeries Data

Data in ISCIDataSeries may be manipulated using the Append, Insert, Update, Remove functions.

In addition, xRange and yRange may be accessed as well as any of the underlying data may be directly accessed.

Also, DataSeries feature two modes: standard and FIFO (First in first out). In FIFO mode data may be streamed and old data-points discarded as new arrive.

Finally, you can control Data Distribution using ISCIDataDistributionCalculator.

The following sections show how you can manipulate data in the DataSeries types in SciChart.

Append, Insert, Update, Remove

All DataSeries types include Append, Insert, Update, Remove methods. Many of these also have overloads which accept a range of data, e.g. the ISCIXyDataSeries protocol has the following:

Other DataSeries have similar methods appropriate to underlying data which they hold.

NOTE: It is highly recommended to use set of methods, which works with our ISCIValues data-structures, to achieve better performance and omit boxing/unboxing into Cocoa native types.

X and Y Ranges

All DataSeries types expose the XRange and YRange of the underlying DataSeries as well as corresponding Max and Min values. See the following methods:

NOTE: These perform a calculation every time the property is accessed, so should be used sparingly.

SCIXyDataSeries *dataSeries = [[SCIXyDataSeries alloc] initWithXType:SCIDataType_Double yType:SCIDataType_Double]; // Append some data here id<ISCIRange> xRange = dataSeries.xRange; id<ISCIRange> yRange = dataSeries.yRange; // You can access Min/Max directly as Double double min = xRange.minAsDouble; double max = xRange.maxAsDouble;
let dataSeries = SCIXyDataSeries(xType: .double, yType: .double) // Append some data here let xRange = dataSeries.xRange; let yRange = dataSeries.yRange; // You can access Min/Max directly as Double let min = xRange.minAsDouble; let max = xRange.maxAsDouble;
var dataSeries = new XyDataSeries<double, double>(); // Append some data here var xRange = dataSeries.XRange; var yRange = dataSeries.YRange; // You can access Min/Max directly as Double var min = xRange.MinAsDouble; var max = xRange.MaxAsDouble;

NOTE: SciChart Xamarin.iOS has generic wrappers to our native DataSeries classes. These generic classes can be constructed and used without the need of the SCIDataType. It will be inferred automatically.

Accessing X, Y, [other] Values

All DataSeries types expose the lists of underlying data. There is a set of protocols, which provides an access for the underlying data, which names has a pattern as follows: ISCI[Something]DataSeriesValues, e.g.:

Those are read-only ISCILists. Data can be accessed by casting to the underlying list type, e.g. ISCIListDouble.

SCIXyDataSeries *dataSeries = [[SCIXyDataSeries alloc] initWithXType:SCIDataType_Double yType:SCIDataType_Double]; id<ISCIList> xValues = dataSeries.xValues; // You can cast each value separately double value = [[xValues valueAt:0] toDouble]; // Or you can cast whole list to needed one, and work with its primitive `itemsArray` id<ISCIListDouble> doubleValues = (id<ISCIListDouble>)xValues; double doubleValue = doubleValues.itemsArray[0];
let dataSeries = SCIXyDataSeries(xType: .double, yType: .double) let xValues = dataSeries.xValues! // You can cast each value separately let value = xValues.value(at: 0).toDouble() // Or you can cast whole list to needed one, and work with it’s primitive `itemsArray` let doubleValues = xValues as! ISCIListDouble let doubleValue = doubleValues.itemsArray[0]
var dataSeries = new XyDataSeries<double, double>(); var xValues = dataSeries.XValues; // You can cast each value separately var value = xValues.ValueAt(0).ToDouble();

Fifo (First-In-First-Out) DataSeries

DataSeries allow First-In-First-Out behaviour, where a maximum capacity is set, once reached, old data-points are discarded. To declare a Fifo dataseries, simply set the ISCIDataSeries.fifoCapacity property.

SCIXyDataSeries *dataSeries = [[SCIXyDataSeries alloc] initWithXType:SCIDataType_Double yType:SCIDataType_Double]; dataSeries.fifoCapacity = 1000;
let dataSeries = SCIXyDataSeries(xType: .double, yType: .double) dataSeries.fifoCapacity = 1000
var dataSeries = new XyDataSeries<double, double>(); dataSeries.FifoCapacity = 1000;

Considering the code above, the behaviour will be the following. Once the 1001-st point have been added, the very first point will be discarded. Appending another 5 points, the next oldest 5 points will be discarded. The window continues to scroll no matter how many points are appended and memory never increases beyond 1000 points.

Fifo DataSeries are a very memory and CPU efficient way of scrolling and discarding old data and creating scrolling, streaming charts.

DataSeries Data Distribution

The ISCIDataDistributionCalculator is a protocol which determines the distribution of your data (sorted in X or not, evenly spaced in X or not) and the flags are used to determine the correct algorithm(s) for resampling, hit-testing and indexing of data.

By default, this all works automatically, however, if you want to save a few CPU cycles and you know in advance the distribution of your data, you can override the flags as follows:

SCIUserDefinedDistributionCalculator *dataDistributionCalculator = [SCIUserDefinedDistributionCalculator new]; dataDistributionCalculator.isDataSortedAscending = YES; dataDistributionCalculator.isDataEvenlySpaced = YES; dataDistributionCalculator.isDataContainsNaN = NO; SCIXyDataSeries *dataSeries = [[SCIXyDataSeries alloc] initWithXType:SCIDataType_Double yType:SCIDataType_Double dataDistributionCalculator:dataDistributionCalculator];
let dataDistributionCalculator = SCIUserDefinedDistributionCalculator() dataDistributionCalculator.isDataSortedAscending = true dataDistributionCalculator.isDataEvenlySpaced = true dataDistributionCalculator.isDataContainsNaN = false let dataSeries = SCIXyDataSeries(xType: .double, yType: .double, dataDistributionCalculator: dataDistributionCalculator)

DataSeries AcceptsUnsortedData

By default, DataSeries are designed to throw an exception if data is appended unsorted in X. This is because unsorted data is detrimental to performance, and many people were unintentionally appending data unsorted in the X-direction.

SciChart can however accept unsorted data, you just need to specify the flag ISCIDataSeries.acceptsUnsortedData = true. This will signal to SciChart that your appending of unsorted data was intentional and the chart will then draw it.

SCIXyDataSeries *dataSeries = [[SCIXyDataSeries alloc] initWithXType:SCIDataType_Double yType:SCIDataType_Double]; dataSeries.acceptsUnsortedData = YES;
let dataSeries = SCIXyDataSeries(xType: .double, yType: .double) dataSeries.acceptsUnsortedData = true
var dataSeries = new XyDataSeries<double, double>(); dataSeries.AcceptsUnsortedData = true;