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PIVMat 3.02

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PIVMat 3.02

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27 Apr 2006 (Updated )

A PIV Post-processing and data analysis toolbox

filterf (PIVMat Toolbox)
filterf (PIVMat Toolbox)
PIVMat Function Reference<< Prev | Next >> 
filterf
Apply a lowpass filter to a vector/scalar field.

Description
FF = filterf(F,FSIZE) applies a Gaussian filter of size FSIZE to the 
vector/scalar field(s) F. If FSIZE is an array, its dimension must 
match the dimension of F. If FSIZE is a scalar, the same filter size is 
applied to each field of F. FSIZE=1 is taken by default if not specified. 
 
FF = filterf(F,FSIZE,METHOD) specifies the filter: 
      'flat':    flat (or top-hat) matrix, ones(FSIZE,FSIZE) 
                 (FSIZE must be an even integer) 
      'gauss':   gaussian (by default) 
      'igauss':  derivative of the integrated gaussian (minimized 
                 discretisation effects for small FSIZE). 
 
Note : If there are missing data in the field, it is better to first 
interpolate the data. See interpf. 
 
The size of the filtered field is smaller than the original field, to 
avoid boundary effects (the convolution is done by CONV2 with the 
option 'valid'). If you prefer to keep the whole field, use 
filterf(F,FSIZE,METHOD,'same') 
 
If no output argument, the result is displayed by showf. 
 
Examples
 
   v = loadvec('*.vc7'); 
   showf(filterf(v)); 
   showf(filterf(v,2,'flat')); 
   showf(filterf(vec2scal(v,'rot'),2)); 
 
See Also
showf, medianf, bwfilterf, addnoisef, interpf, 
GAUSSMAT, CONV2. 
 
Published output in the Help browser 
   showdemo filterf 

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