Chart Element

Summary ¶

	Chart
Info
Category:	Data Collection		AddIn:	Psychophysics
Creator:	OkazoLab		Scope:	Experiment
Owns Snippets:	None		Usage:	Snippets

Properties ¶

Name	Description	Constraints	Type	On runtime change
Settings
Open Chart Designer	Opens a designer dialog, in which you can manage chart's datasets and choose visualization settings.	Design Time..	Boolean
Rendering Size	Defines the size of the produced chart in pixels. The chart is automatically stretched on rendering, but a larger rendering size improves the chart quality with some cost in performance. The rendering size is also used as the resulting image resolution, when the chart is saved into a file.	Design Time..	clSize
Runtime Status
Data Sets	Returns a fixed array containing references to the chart's dataset. Each dataset, in turn, is a .Net List structure that stores chart data points. Using this property you can add, change and  remove the data points at runtime.	Normal..	clData..
XAML Chart	Returns a live XAML chart control that can be visualized by direct binding to the Content property of the XAML ContentControl element, e.g. ContentControl with a chart can be added to the status screen or to the XAML Layout element.	Normal..	UIElem..
Save Chart Now	Use this runtime command whenever you want to save a screenshot of the generated chart. To run the command, assign a string with a full file path and name to this property in a code snippet. The screenshot will be saved into the target file after the end of the snippet call. The format of the image file is defined by the extension of the file name, e.g. .bmp, .png or .jpg	Runtime Command..	String
Dataset Statistics
Count	Returns an int array containing the numbers of the Y values within each dataset.	Normal..	Int32[]
Mean	Returns a double array containing the means of the Y values within each dataset.	Normal..	Double..
Median	Returns a double array containing the medians of the Y values within each dataset.	Normal..	Double..
Minimum	Returns a double array containing the minimum of the Y values within each dataset.	Normal..	Double..
Maximum	Returns a double array containing the maximum of the Y values within each dataset.	Normal..	Double..
Standard Deviation	Returns a double array containing the standard deviations of the Y values within each dataset.	Normal..	Double..
Standard Error	Returns a double array containing the standard errors of the Y values within each dataset.	Normal..	Double..
Confidence Interval	Returns a double array containing half-length of the 95% confidence intervals (approx!) for the mean taken over the Y values within each dataset.	Normal..	Double..
Control
Is Enabled	If set to false the element is completely omitted when the experiment is run	Design Time..	Boolean
Title	Title of the element	Design Time..	String

¶

Description ¶

Snapshots ¶

Bar chart showing distribution of RTs

Box-and-Whisker Plot showing difference between 2 conditions

Data representation ¶

• A numerical pair of X-Y values (a dataset may contain any number of the X-Y pairs that may overlap)
• Indexed Y values (For each Y value in a dataset, its X counterpart is defined by an Y value's index in the dataset. Correspondingly, there is can only one Y value for every integer index from 0 to N)
• Text values, or pairs of X-Text values (the text data points are used to store labels for chart's axis)
  

3 datasest with test data points (left) and the generated chart (right). The datasets include: 1) indexed Y values (histogram plot), b) X-Y pairs (scatter plot), c) X-Text values (labels for the X axis) Click on the screenshot to enlarge

Chart designer ¶

Plot Styles ¶

Basic Plots ¶

/	Lines	Bars	Scatter	Mountain	Histogram
Description	Visualizes data as a set of points connected by a line	Visualizes data as a set of bars	Visualizes data as a set of points	Visualizes data as a set of connected points with a filled area below a line	Visualizes the frequency distribution of the Y values (not values themselves!), which are automatically allocated into 9 adjacent categories along the X-Axis
Data points	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values	Indexed Y values
Example	<

Statistical Box-and-Whisker Plots ¶

/	Mean.SE.SD	Mean.SE.CI	Mean.SE	Mean.CI	Median.SE.SD	Median.SE.CI
Description	Visualizes data in a set of box-and-whiskers, in which the data mean is shown as middle line, standard error as bar and standard deviation as whiskers.	Visualizes data in a set of box-and-whiskers, in which the data mean is shown as middle line, standard error as bar and confidence interval as whiskers.	Visualizes data in a set of box-and-whiskers, in which the data mean is shown as middle line and standard error as whiskers.	Visualizes data in a set of box-and-whiskers, in which the data mean is shown as middle line and confidence interval as whiskers.	Visualizes data in a set of box-and-whiskers, in which the data median is shown as middle line, standard error as bar and standard deviation as whiskers.	Visualizes data in a set of box-and-whiskers, in which the data median is shown as middle line, standard error as bar and confidence interval as whiskers.
Data points	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values	X-Y values, Indexed Y values
Example

Practical Use ¶

Creating a simple chart on the status screen ¶

1. Add the Chart element to any event in your experiment
2. Select the element and open the chart designer
3. Create as many datasets as needed and select plot styles and visualization settings. You can enter some test data to check the chart appearance
4. Close the chart designer and select Online Chart property of the element
5. Create a proxy variable linked to Online Chart property
6. Open the status screen editor and add an empty XAML content control, e.g.:
   

    <ContentControl Width="640" Height="480" Content='{Binding OnlineChart}'/> 

   
   Note that the Content property has to be bound to the OnlineChart proxy variable
7. Close the status screen editor and select Data Sets property of the element
8. Create a proxy variable linked to Data Sets property.
9. Write your code that modifies the Data Sets at runtime using the DataSets proxy variable, e.g:
   

   
   
   if (TrialCondition==1)
   
   DataSets[0].Add(RT); // saving the trial RT to the dataset for the condition 1
   
   if (TrialCondition==2)
   
   DataSets[1].Add(RT); // saving the trial RT to the dataset for the condition 2
   
   

   
   

Operating chart's datasets in code ¶

// adding new data
DataSets[0].Add(0.5); // adds a new indexed Y value to the dataset
DataSets[1].Add(10.0,24.2); // adds a new X-Y pair to the dataset
DataSets[2].Add(10,"Ten"); // adds a new mark for X=10 in the label's dataset

// removing data
DataSets[0].Clear(); // cleans up the dataset
DataSets[1].RemoveAt(n); // removes the n-th element in the dataset
DataSets[2].RemoveAt(DataSets[2].Count-1,"Ten"); // removes the last mark in the label's dataset

// modifying datasets
DataSets[0][0]=0.25; // replaces the first Y value in the dataset
DataSets[1][0]=DataSets[1][0]+1; // increments the first Y value in the dataset by 1

// modifying a selected datapoint by its fields
DataSets[2][0].X=3; // changes the X value
DataSets[2][0].Y=7.4; // changes the Y value
DataSets[2][0].Label="X=3"; // changes the Label value (it affects only the label's datasets)

// Note that you always have to access a particular dataset with an index in the first bracket group, like DataSet[0] This gives a reference to .NET list.