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mio::ProcExpSmoothing Class Reference

Detailed Description

Exponential smoothing. This implements an exponential moving average smoothing of parameter alpha (https://en.wikipedia.org/wiki/Exponential_smoothing) such as (s being the filtered values and x the raw data):

  • s_0 = x_0
  • s_n = alpha*x_(t-1) + (1-alpha)*s_(t-1)

Nodata values are excluded from the moving average calculation. It takes the following options:

  • an optional "soft" keyword to allow (or not) the window centering to be adjusted to the available data
  • the keywords "left", "center" or "right", indicating the window centering strategy
  • the minimal number of points in window
  • the minimal time interval spanning the window (in seconds)
  • the alpha parameter, such as 0 < alpha < 1

The standard behavior for this filter is obtained by using a left window. If using a right window, it behaves as if time was reversed (ie. predictions from the future). A centered window applies the standard algorithms on the distance between the center point and each points, that is that points get averaged symetrically around the middle point before running the standard algorithm.

Note
This filter temporally shifts the signal back by window_width/2 if using left or right window
This would probably lead to slightly unexpected results if used on irregularly sampled data
TA::filter1 = exp_smoothing
TA::arg1 = right 1 1800 0.8 ;(1800 seconds time span for the strictly right leaning window), alpha=0.8
RH::filter1 = mean_avg
RH::arg1 = 10 600 0.6 ;(strictly left window spanning 600 seconds and at least 10 points), alpha=0.6

#include <ProcExpSmoothing.h>

Public Member Functions

 ProcExpSmoothing (const std::vector< std::string > &vec_args, const std::string &name)
 
virtual void process (const unsigned int &param, const std::vector< MeteoData > &ivec, std::vector< MeteoData > &ovec)
 
- Public Member Functions inherited from mio::WindowedFilter
 WindowedFilter (const std::string &name)
 
- Public Member Functions inherited from mio::FilterBlock
virtual ~FilterBlock ()
 
- Public Member Functions inherited from mio::ProcessingBlock
virtual ~ProcessingBlock ()
 
std::string getName () const
 
const ProcessingPropertiesgetProperties () const
 
const std::string toString () const
 

Additional Inherited Members

- Public Types inherited from mio::WindowedFilter
enum  Centering { left, center, right }
 
- Protected Member Functions inherited from mio::WindowedFilter
const std::vector< const
MeteoData * > & 
get_window (const size_t &index, const std::vector< MeteoData > &ivec)
 A function that cuts out the desired window for the 'index' element within ivec, the window elements are stored into vec_window Calls to this function have to start with index 0, then 1, 2, 3, ... vec_window is not allowed to be changed between two calls. More...
 
bool get_window_specs (const size_t &index, const std::vector< MeteoData > &ivec, size_t &start, size_t &end) const
 A function that computes the start and end for a window for the 'index' element from ivec The principle is too compute the first index that matches the minimum number of points criteria, and the one that matches the minimum time window, then combine them (with the equivalent of OR: we take the MIN index). Afterward, we compute the last index [...] for number of points and the last index [...] for the time window and combine them (with the equivalent of OR: we take the MIN index) or vice versa for right centering. More...
 
- Protected Member Functions inherited from mio::FilterBlock
 FilterBlock (const std::string &filter_name)
 protected constructor only to be called by children More...
 
- Protected Member Functions inherited from mio::ProcessingBlock
 ProcessingBlock (const std::string &name)
 protected constructor only to be called by children More...
 
void convert_args (const size_t &min_nargs, const size_t &max_nargs, const std::vector< std::string > &vec_args, std::vector< double > &dbl_args) const
 
- Static Protected Member Functions inherited from mio::WindowedFilter
static unsigned int get_centering (std::vector< std::string > &vec_args)
 
- Static Protected Member Functions inherited from mio::FilterBlock
static void extract_dbl_vector (const unsigned int &param, const std::vector< MeteoData > &ivec, std::vector< double > &ovec)
 
static void extract_dbl_vector (const unsigned int &param, const std::vector< const MeteoData * > &ivec, std::vector< double > &ovec)
 
- Static Protected Member Functions inherited from mio::ProcessingBlock
static bool is_soft (std::vector< std::string > &vec_args)
 
static void readCorrections (const std::string &filter, const std::string &filename, const char &c_type, const double &init, std::vector< double > &corrections)
 
- Protected Attributes inherited from mio::WindowedFilter
Duration min_time_span
 
Centering centering
 
size_t last_start
 
size_t last_end
 
size_t min_data_points
 
bool is_soft
 
- Protected Attributes inherited from mio::ProcessingBlock
ProcessingProperties properties
 
const std::string block_name
 
- Static Protected Attributes inherited from mio::ProcessingBlock
static const double soil_albedo = .23
 
static const double snow_albedo = .85
 
static const double snow_thresh = .1
 parametrize the albedo from HS More...
 

Constructor & Destructor Documentation

mio::ProcExpSmoothing::ProcExpSmoothing ( const std::vector< std::string > &  vec_args,
const std::string &  name 
)

Member Function Documentation

void mio::ProcExpSmoothing::process ( const unsigned int &  param,
const std::vector< MeteoData > &  ivec,
std::vector< MeteoData > &  ovec 
)
virtual

Implements mio::WindowedFilter.


The documentation for this class was generated from the following files: