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2.2.23 reducedup

Menu Information

Analysis: Data Manipulation: Reduce Duplicate X Data

Brief Information

Reduce XY data by replacing duplicated X values

Additional Information

Minimum Origin Version Required: 8.1 SR0

Command Line Usage

reducedup method:=mean tol:=1 xcount:=<new>

Variables

Display
Name
Variable
Name
I/O
and
Type
Default
Value
Description
Input iy

Input

XYRange

<active>
Specifies the input data range.
Replace Y With method

Input

int

0
Specifies the value that is used to replace the Y values that correspond to equal X values.

Option list:

  • mean:Mean
    Replaces the data points in each group with the mean value of these data points.
  • median:Median
    Replaces the data points in each group with the median value of these data points.
  • min:Min
    Replaces the data points in each group with the minimum value of these data points.
  • max:Max
    Replaces the data points in each group with the maximum value of these data points.
  • sum:Sum
    Replaces the data points in each group with the sum of these data points.
  • sd:SD
    Replaces the data points in each group with the standard deviation of the Y values of these data points.
  • se:SE
    Replaces the data points in each group with the standard error of the Y values of these data points.
  • rms:RMS
    Replaces the data points in each group with the Root-Mean-Square of the Y values of these data points.
Tolerance tol

Input

double

1.0e-8
Specifies the tolerance used to test whether two X values are equal. For more details, please refer to the Algorithm section below.
Output oy

Output

XYRange

<new>
Specifies the output range. See the syntax of Output Notations.
Duplicate X Counts xcount

Output

XYRange

<new>
Specifies whether or not to output the count of duplicate X. See the syntax of Output Notations.

Description

This X-Function is for removing data rows that have duplicated X values. After reducing the input data with this X-Function, there will not be any pair of X values that are equal to each other. The Y values that correspond to equal X values in the original data will be replaced with a chosen statistical quantity.

Example

The following example shows you how to reduce several rows of data that contain duplicate X values.

  1. Create a workbook and import the data <Origin Program Folder>\Samples\Mathematics\Circle.dat.
  2. Highlight the columns in the worksheet and select Plot: Line: Line from the main menu to create a graph.
    Reducedup-1.png
  3. Make the graph active. Select Analysis: Data Manipulation: Reduce Duplicate X Data from the Origin menu to open the dialog box of the reducedup X-Function.
  4. Check Auto Preview so that we can see the current result in the Preview window when we change the dialog options.
  5. Choose Min with the Replace Y With drop-down list.
  6. Check Duplicate X Counts and enter [<new>]<new> after it. This ensures that you will get the counts of duplicate Xs after reducing the data.
    Reducedup-2.png
  7. Click the OK button. You can see the results in the original workbook and the graph.
    Reducedup-3.png
  8. Now we plot the reduced data separately. Go to the workbook. Highlight col(C) and col(D). Select Plot: Line: Line from the Origin menu to create a new graph.
    Reducedup-4.png

Algorithm

  • Tolerance for testing whether two values are equal

Some X-Functions that test for equality include a tolerance. This algorithm tests whether two X values are equal.

For a given vector, firstly sort it ascending, and suppose the sorted vector is \left (x_1, x_2, x_3, ..., x_n \right ), where n is the size of the vector. The following steps are the procedure for testing whether two X values are equal with a specified tolerance, tol.

  1. Find the maximum and minimum of the vector, say max and min respectively.
  2. Calculate a testing value, dTol, by using:
    dTol = tol * \left ( max - min \right )
  3. Loop over all values in the sorted vector, from x_1 to x_n, comparing the absolute value of \left ( x_n - x_{n-1} \right) with dTol.
    If abs \left ( x_n - x_{n-1} \right ) \le dTol, we will say that x_n = x_{n-1} \,, else, x_n \ne x_{x-1}.
  4. When multiple X values are determind equal, say \left ( x_i, x_{i+1}, ..., x_j \right ), where 1 \le i < j \le n, the display X value for this "equal" X values is defined as:
    If the number of this "equal" X values is even, the display X value is x_{\frac {i + j - 1}{2}}.
    If the number of this "equal" X values is odd, the display X value is x_{\frac {i + j}{2}}.

Related X-Functions

stats, reducexy


Keywords:data reduction, average, mean, sum, minimum, maximum, statistics

 

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