﻿ RFrequencyTableOL(Series,Double[]) Method
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 dotnetCHARTING Namespace > StatisticalEngine Class > RFrequencyTableOL Method : RFrequencyTableOL(Series,Double[]) Method

s
A statistical series.
boundaries
A strictly increasing sequence of boundaries of the intervals over the real line in which the data sets point will be assigned.
Calculates the relative frequency table for a discrete data set in accordance with the open left boundary (OLB) convention.

# Syntax

Visual Basic (Declaration)
```Public Overloads Shared Function RFrequencyTableOL( _
ByVal s As Series, _
ByVal boundaries() As Double _
) As Series```
Visual Basic (Usage)Copy Code
``````Dim s As Series
Dim boundaries() As Double
Dim value As Series

value = StatisticalEngine.RFrequencyTableOL(s, boundaries)``````
C#
```public static Series RFrequencyTableOL(
Series s,
double[] boundaries
)```

#### Parameters

s
A statistical series.
boundaries
A strictly increasing sequence of boundaries of the intervals over the real line in which the data sets point will be assigned.

# Remarks

The relative frequency table normalized the data with regard to the size of the data set before evaluating the frequency table is exactly the same fashion as StatisticalFrequencyTableOL.

### Further Explanation

If we are comparing two or more data sets then the frequencies should be normalized to reflect the possible different sizes of the data sets themselves. To normalize a data set we much first divide the data set into a collection of classes into which the elements are assigned. Here we assign the data set in accordance with the open left boundary convention where the class frequencies are just the number of elements within each of the sub-intervals of the real line in accordance with the open left boundary convention (see example below).

To evaluate the relative frequency we apply the following formula to each class:

Relative frequency = (class frequency) / (total frequency)

where the class frequency is the number of data points within a given sub-interval of the real line, and the total frequency is the total number of elements within the data set considered.

#### Example Illustration the Open Left Boundary Convention

Consider the set of boundaries `{ b_1, b_2, b_3, b_4, b_5 }`, where `b_1 < b_2 < b_3 < b_4 < b_5`, which divide the real line into six sub-intervals. Now if we use the open left boundary convention then the real line will be divided into the sub-intervals:

(-infinity, b_1], (b_1,b_2], (b_2,b_3], (b_3,b_4], (b_4,b_5], (5, infinity)

Note that, each point on the real line can be assigned to one of these sub-intervals and therefore when assigning a data point to one of these intervals there will only be one sub-interval in which it belongs.