Last change
on this file since 258 was
258,
checked in by Matthew Whiting, 17 years ago
|
Merging pixel-map-branch revisions 236:257 back into trunk.
The use of the PixelMap? functions is sorted now, so we put everything back into a uniform location.
|
File size:
1.7 KB
|
Line | |
---|
1 | #include <iostream> |
---|
2 | #include <math.h> |
---|
3 | #include <Utils/Hanning.hh> |
---|
4 | |
---|
5 | Hanning::Hanning(){ |
---|
6 | allocated=false; |
---|
7 | }; |
---|
8 | Hanning::~Hanning(){ |
---|
9 | if(allocated) delete [] coeffs; |
---|
10 | }; |
---|
11 | |
---|
12 | Hanning::Hanning(int size){ |
---|
13 | /** |
---|
14 | * Constructor that sets the Hanning width and calculates the coefficients. |
---|
15 | * \param size The full width of the filter. The parameter \f$a\f$ is |
---|
16 | * defined as (size+1)/2. |
---|
17 | */ |
---|
18 | if(size%2==0){ |
---|
19 | std::cerr << "Hanning: need an odd number for the size. " |
---|
20 | << "Changing "<< size << " to " << ++size<<".\n"; |
---|
21 | } |
---|
22 | hanningSize = size; |
---|
23 | coeffs = new float[size]; |
---|
24 | allocated = true; |
---|
25 | float a = (size+1.)/2.; |
---|
26 | for(int i=0;i<size;i++){ |
---|
27 | float x = i-(size-1)/2.; |
---|
28 | coeffs[i] = 0.5 + 0.5*cos(x * M_PI / a); |
---|
29 | } |
---|
30 | }; |
---|
31 | |
---|
32 | |
---|
33 | float *Hanning::smooth(float *array, int npts){ |
---|
34 | /** |
---|
35 | * This smooths an array of float by doing a discrete convolution of |
---|
36 | * the input array with the filter coefficients. |
---|
37 | * |
---|
38 | * Currently only works for C arrays of floats, as that is all I |
---|
39 | * need it for. Could be made more general if needs be. |
---|
40 | * |
---|
41 | * \param array The input array. Needs to be defined -- no memory |
---|
42 | * checks are done! \param npts The size of the input array. |
---|
43 | * \return Returns an array of the same size. If filter coefficients |
---|
44 | * have not been allocated, the input array is returned. |
---|
45 | */ |
---|
46 | if(!this->allocated) return array; |
---|
47 | else{ |
---|
48 | float *newarray = new float[npts]; |
---|
49 | float scale = (hanningSize+1.)/2.; |
---|
50 | for(int i=0;i<npts;i++){ |
---|
51 | newarray[i] = 0.; |
---|
52 | for(int j=0;j<hanningSize;j++){ |
---|
53 | int x = j-(hanningSize-1)/2; |
---|
54 | if((i+x>0)&&(i+x<npts)) newarray[i]+=coeffs[j] * array[i+x]; |
---|
55 | } |
---|
56 | newarray[i] /= scale; |
---|
57 | } |
---|
58 | return newarray; |
---|
59 | } |
---|
60 | }; |
---|
Note: See
TracBrowser
for help on using the repository browser.