Method ao/detrend
DETREND detrends the input analysis object using a polynomial of degree N.
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DESCRIPTION: DETREND detrends the input analysis object using a
polynomial of degree N.
CALL: b = detrend(a1,a2,a3,..., pl)
INPUTS: aN - a list of analysis objects
pl - a parameter list
OUTPUTS: b - array of analysis objects
If the last input argument is a parameter list (plist) it is used.
The following parameters are recognised.
NOTE: detrend uses two possible algorithms. A fast C-code implementation
is used for orders less than 11. If the order is higher than 10, then a
MATLAB code is used which is typically much slower. You can also force
the use of the MATLAB code using a plist option. When interpreting the
resulting coefficients, you must be clear which algorithm was used. For
the C-code algorithm, the coefficients are scaled from the original by
z = 2.*ii/(n-1)-1;
such that the functional form (for a three-coefficient example) that is
subtracted from the data can be recovered with:
fitted_c = c.y(3).*z.^2 + c.y(2).*z + c.y(1);
The procinfo field of the output AOs is filled with the following key/value
pairs:
'COEFFS' - pest object with coefficients describing the subtracted trend function
Note that they correspond to physical trend coefficents
only if using the (slower) option 'M-FILE ONLY'. In the
case of using the C-code algorith, see the note above.
Parameters Description
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Method Details |
|
Access |
public |
Defining Class |
ao |
Sealed |
0 |
Static |
0 |
Parameter Description
Sets for this method … |
Default |
Default |
no description |
Key |
Default Value |
Options |
Description |
ORDER, N |
1 |
|
The order of detrending:- -1 - no detrending
- 0 - subtract mean
- 1 - subtract linear fit
- N - subtract fit of polynomial, order N
|
M-FILE ONLY |
0 |
|
Using SLOWER m-file call |
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Some information of the method ao/detrend are listed below: |
Class name |
ao |
Method name |
detrend |
Category |
Signal Processing |
Package name |
ltpda |
VCS Version |
8ab8cbbc4bccf7543491a24448f4aae0b1be1c43 |
Min input args |
1 |
Max input args |
-1 |
Min output args |
1 |
Max output args |
-1 |
|
Method: ao/delayEstimate |
|
Method: ao/dft |
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©LTP Team