Med2top: Difference between revisions

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===Purpose===
===Purpose===
Fits a constant to top/(bottom) of data.
Fits a constant to top/(bottom) of data.
===Synopsis===
===Synopsis===
:[yf,residual,options] = med2top(y,options)
:[yf,residual,options] = med2top(y,options)
===Description===
===Description===
MED2TOP is similar to LSQ2TOP with a 0 order polynomial, it can be considered an asymmetric estimate of the mean.
MED2TOP is similar to LSQ2TOP with a 0 order polynomial, it can be considered an asymmetric estimate of the mean.
For fitting to the bottom:
For fitting to the bottom:
>> tsq = residual/res; % (res) is an input
 
<pre>>> tsq = residual/res; % (res) is an input
 
>> tsqst = ttestp(1-options.tsqlim,5000,2); % T-test limit from table
>> tsqst = ttestp(1-options.tsqlim,5000,2); % T-test limit from table
>> ii = find(tsq>-tsqst); % finds samples below the line
 
>> ii = find(tsq>-tsqst); % finds samples below the line</pre>
 
The ii samples are kept for the next estimate of (yf):
The ii samples are kept for the next estimate of (yf):
>> yf = median(y(ii));
 
INPUTS:
<pre>>> yf = median(y(ii));</pre>
* y = trace to be filtered, Mx1 vector.
 
OUTPUTS:
====Inputs====
* yf = scalar, estimate of filtered data.
 
* residual = y - yf.
* '''y''' = trace to be filtered, Mx1 vector.
* options = input options echoed back, the field initwt may have been modified.
 
====Outputs====
 
* '''yf''' = scalar, estimate of filtered data.
 
* '''residual''' = y - yf.
 
* '''options''' = input options echoed back, the field initwt may have been modified.
 
===Options ===
===Options ===
*'' ''options'' '' = a structure array with the following fields.
 
* display: [ {'off'} | 'on'] Governs screen display to command line.
*'''''''' ''options'' '' = a structure array with the following fields.
* trbflag: [ {'top'} | 'bottom' | 'middle']  flag that tells algorithm to fit to the top, bottom, or middle of the data cloud.
 
* tsqlim:  [ 0.99 ] limit that govers whether a data point is outside the fit residual defined by input (res).
* '''display''': [ {'off'} | 'on'] Governs screen display to command line.
* stopcrit: [1e-4 1e-4 1000 360] stopping criteria, iteration is continued until one of the stopping criterion is met [(rel tol) (abs tol) (max \# iterations) (max time [seconds])].
 
* initwt: [ ] empty or Mx1 vector of initial weights (0<=w<=1).
* '''trbflag''': [ {'top'} | 'bottom' | 'middle']  flag that tells algorithm to fit to the top, bottom, or middle of the data cloud.
 
* '''tsqlim''':  [ 0.99 ] limit that govers whether a data point is outside the fit residual defined by input (res).
 
* '''initwt''': [ ] empty or Mx1 vector of initial weights (0<=w<=1).
 
===See Also===
===See Also===
[[baseline]], [[baslinew]], [[fastnnls]], [[lsq2top]]
[[baseline]], [[baslinew]], [[fastnnls]], [[lsq2top]]

Latest revision as of 10:31, 10 June 2014

Purpose

Fits a constant to top/(bottom) of data.

Synopsis

[yf,residual,options] = med2top(y,options)

Description

MED2TOP is similar to LSQ2TOP with a 0 order polynomial, it can be considered an asymmetric estimate of the mean.

For fitting to the bottom:

>> tsq = residual/res; % (res) is an input

>> tsqst = ttestp(1-options.tsqlim,5000,2); % T-test limit from table

>> ii = find(tsq>-tsqst); % finds samples below the line

The ii samples are kept for the next estimate of (yf):

>> yf = median(y(ii));

Inputs

  • y = trace to be filtered, Mx1 vector.

Outputs

  • yf = scalar, estimate of filtered data.
  • residual = y - yf.
  • options = input options echoed back, the field initwt may have been modified.

Options

  • ''' options = a structure array with the following fields.
  • display: [ {'off'} | 'on'] Governs screen display to command line.
  • trbflag: [ {'top'} | 'bottom' | 'middle'] flag that tells algorithm to fit to the top, bottom, or middle of the data cloud.
  • tsqlim: [ 0.99 ] limit that govers whether a data point is outside the fit residual defined by input (res).
  • initwt: [ ] empty or Mx1 vector of initial weights (0<=w<=1).

See Also

baseline, baslinew, fastnnls, lsq2top