:: com :: sun :: star :: chart2 ::

interface XRegressionCurveCalculator

Methods' Summary
setRegressionProperties  
recalculateRegression recalculates the parameters of the internal regression curve according to the x- and y-values given.  
getCurveValue calculates the value of the regression curve for x.  
getCurveValues calculate multiple points of a regression curve at once. Note that this method may optimize the output by returning less points, e.g. for a line you may get only two resulting points instead of nPointCount() points. This is only allowed if the parameter bMaySkipPointsInCalculation() is set to `TRUE`.  
getCorrelationCoefficient Returns the value of the correlation coefficient for the given regression. This value is often denoted as r or R.  
getRepresentation Retrieve a string showing the regression curve's function with calculated parameters.  
getFormattedRepresentation Returns a representation using the given number format for formatting all numbers contained in the formula. Wrap equation to fit in nFormulaLength characters  
setXYNames Set the names of X and Y variables of the equation to replace "x" and "f(x)" in representation  
Methods' Details
setRegressionProperties
void
setRegressionProperties( [in] long  degree,
[in] boolean  forceIntercept,
[in] double  interceptValue,
[in] long  period );

recalculateRegression
void
recalculateRegression( [in] sequence< double >  aXValues,
[in] sequence< double >  aYValues );

Description
recalculates the parameters of the internal regression curve according to the x- and y-values given.
Parameter aXValues
All x-values that represent the measurement points on which the regression is based
Parameter aYValues
All y-values that represent the measurement points on which the regression is based
getCurveValue
double
getCurveValue( [in] double  x )
raises( ::com::sun::star::lang::IllegalArgumentException );

Description
calculates the value of the regression curve for x.
Parameter x
The abscissa value for which the value of the regression curve should be calculated. All numbers that are part of the domain of the regression function are valid.
Returns
If x is element of the domain of the regression curve function, the result is its value.
Throws
com::sun::star::lang::IllegalArgumentException If x is not part of the domain of the regression function.
getCurveValues
sequence< ::com::sun::star::geometry::RealPoint2D >
getCurveValues( [in] double  min,
[in] double  max,
[in] long  nPointCount,
[in] XScaling  xScalingX,
[in] XScaling  xScalingY,
[in] boolean  bMaySkipPointsInCalculation )
raises( ::com::sun::star::lang::IllegalArgumentException );

Description
calculate multiple points of a regression curve at once. Note that this method may optimize the output by returning less points, e.g. for a line you may get only two resulting points instead of nPointCount() points. This is only allowed if the parameter bMaySkipPointsInCalculation() is set to `TRUE`.

It is important that a renderer takes the scalings into account. When one of these parameters is unknown, no optimization must be done.

Parameter min
the abscissa value for the starting point.
Parameter max
the abscissa value for the ending point.
Parameter nPointCount
the number of points to calculate.
Parameter bMaySkipPointsInCalculation
determines whether it is allowed to skip points in the calculation. When this parameter is `TRUE` it is assumed that the underlying coordinate system is Cartesian.
Parameter xScalingX
a scaling that is used for the values in x-direction
Parameter xScalingY
a scaling that is used for the values in y-direction
getCorrelationCoefficient
double
getCorrelationCoefficient();

Description
Returns the value of the correlation coefficient for the given regression. This value is often denoted as r or R.

The value of r is signed. Often r2 is used instead of r to denote a regression curve's accuracy.

Returns
The return value is the fraction of the variance in the data that is explained by the regression.
getRepresentation
string
getRepresentation();

Description
Retrieve a string showing the regression curve's function with calculated parameters.
Returns
The string returned contains the regression curve's formula in a form
"f(x) = ..."
, where the calculated parts are filled out. For a linear regression you might get
"f(x) = 0.341 x + 1.45"
.
getFormattedRepresentation
string
getFormattedRepresentation( [in] ::com::sun::star::util::XNumberFormatsSupplier  xNumFmtSupplier,
[in] long  nNumberFormatKey,
[in] long  nFormulaLength );

Description
Returns a representation using the given number format for formatting all numbers contained in the formula. Wrap equation to fit in nFormulaLength characters
See also
getRepresentation
setXYNames
void
setXYNames( [in] string  aXName,
[in] string  aYName );

Description
Set the names of X and Y variables of the equation to replace "x" and "f(x)" in representation
Parameter aXName
string of the name of X variable
Parameter aYName
string of the name of Y variable
Top of Page