Remove Undercuts

版本 1.0.0 (2.9 KB) 作者: William Rose

Remove undercuts from an x,y data set. This can make it possible to interpolate a data set that otherwise could not be.

关注

0.0

(0)

5.0 次下载

更新时间 2021/12/9

查看许可证

function [xout,yout]=undercutRemoval(xin,yin,varargin)

Remove undercuts from an x,y dataset.

An undercut or uppercut (collectively, undercuts) in an x,y data set is one or more data points whose x values are less than or equal to previous x-values. In other words, an undercut is a data segment that "curves back on itself". Data sets with undercuts cannot be interpolated with interp1(). Removing the undercuts will make the data interpolate-able. The user may specify one of four methods, or not. Method 1 is the default. Figure below shows the difference between methods.

Method 1: Remove down-going undercuts by a two-pass approach
Method 2: Remove up-going uppercuts by a two-pass approach
Method 3: Remove under- and uppercuts, proceeding from beginning to end
Method 4: Remove under- and uppercuts, proceeding from end to beginning

See undercutRemovalTest.m for a demonstration of the function and example of the different methods. The demonstration program uses data in file undercutdata.txt.

I beleive the following statements are true, but have not proved them:

Method 1 has an upward bias, i.e. mean(yout)>=mean(yin)
Method 2 has a downward bias, i.e. mean(yout)<=mean(yin)
Methods 3,4 are unbiased, i.e. exp.val(mean(yout))=exp.val.(mean(yin))

引用格式

William Rose (2024). Remove Undercuts (https://www.mathworks.com/matlabcentral/fileexchange/103195-remove-undercuts), MATLAB Central File Exchange. 检索来源 2024/4/26.