<bestFitLine>

<bestFitLine> is a Graphical component computes a linear regression through a list of points. When nested inside a <graph>, the <bestFitLine> component displays a line.
The equation for the line of best fit can be rendered by accessing the equation property.

Attributes and Properties

Example: <bestFitLine> through 3 points

 <graph size="small">
    <bestFitLine data="$p1 $p2 $p3"/>
    <point name="p1">(-6,-4)</point>
    <point name="p2">(-2,0)</point>
    <point name="p3">(5,3)</point>
  </graph>

A <bestFitLine> is rendered through three named <point> components. Note that the data in this example are not specified as fixed and when the points are moved the regression line will update accordingly.

Example: <bestFitLine> from user-input

 <p>Enter 3 points: <mathInput name="input1"/>, <mathInput name="input2"/>, 
 <mathInput name="input3"/></p>
 
    <point name="p1">$input1</point>
    <point name="p2">$input2</point>
    <point name="p3">$input3</point>
 
  <graph size="small">
    <bestFitLine data="$p1 $p2 $p3"/>
    $p1 
    $p2
    $p3
  </graph>

A <bestFitLine> is rendered through three named <point> components. Coordinates for the points are provided by the user with the <mathInput/> component.

Example: Plot data and determine equation

A <bestFitLine> is rendered through an arbitrary number of data points generated with a <callAction> component that adds <point> children to the named <graph>.

The <collect> component gathers the information required from the <graph> to provide to the data attribute of the <bestFitLine> without having to assign individual names to each <point>.

Attribute Example: data

 <graph size="small">
    <bestFitLine data="(-6,-4) (-2,0) (5,3)"/>
  </graph>

The data attribute specifies the data points through which to fit a regression.

Attribute Example: variables

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)" variables="t z"/>
</graph>
<p><c>equation</c> = $line1.equation</p>

The variables attribute allows customization of the independent and dependent variable name when rendering the equation of the computed regression line.

Property Example: equation

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
</graph>
<p><c>equation</c> = $line1.equation</p>

The equation property of the named <bestFitLine> renders the equation of the computed regression line.

Property Example: slope

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
</graph>
<p><c>slope</c> = $line1.slope</p>

The slope property of the named <bestFitLine> renders the slope of the computed regression line.

Property Example: coeff0, coeffVar1, coeffVar2

Linear coefficients corresponding to the linear form A x + B y + C = 0 can be obtained with the above properties, where $C =$coeff0, $B =$coeffVar2 and $A =$coeffVar1.

Property Example: xIntercept, yIntercept

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
</graph>
<p><c>xIntercept</c> = $line1.xIntercept</p>
<p><c>yIntercept</c> = $line1.yIntercept</p>

Use the xIntercept and yIntercept properties of the named <bestFitLine> to determine the intercepts of the computed regression line.

Property Example: latex

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
</graph>
<p><c>latex</c> = $line1.latex</p>

The latex property renders the latex code for rendering the equation of the computed regression line.

Property Example: data

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
  $line1.data{styleNumber="2"}
</graph>
<p><c>data</c> = <asList>$line1.data</asList></p>
<p><c>data[2]</c> = $line1.data[2]</p>

The data property renders two through points computed for the linear regression.

Property Example: variables

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
  $line1.data{styleNumber="2"}
</graph>
<p><c>variables</c> = <asList>$line1.variables</asList></p>

The variables property renders the two variables used when rendering the equation for the linear regression.

Property Example: numDimensions

<graph size="small">
  <bestFitLine name="line1" data="(-6,-4) (-2,0) (5,3)"/>
</graph>
<p><c>numDimensions</c> = <asList>$line1.numDimensions</asList></p>

The numDimensions property renders the number of dimensions for the linear regression.