File indexing completed on 2024-04-21 05:50:08

 /*
     SPDX-FileCopyrightText: 2001-2013 Evan Teran <evan.teran@gmail.com>
     SPDX-FileCopyrightText: 1996-2000 Bernd Johannes Wuebben <wuebben@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "stats.h"
 
 //------------------------------------------------------------------------------
 // Name: KStats
 // Desc: constructor
 //------------------------------------------------------------------------------
 KStats::KStats() = default;
 
 //------------------------------------------------------------------------------
 // Name: ~KStats
 // Desc: destructor
 //------------------------------------------------------------------------------
 KStats::~KStats() = default;
 
 //------------------------------------------------------------------------------
 // Name: clearAll
 // Desc: empties the data set
 //------------------------------------------------------------------------------
 void KStats::clearAll()
 {
     data_.clear();
 }
 
 //------------------------------------------------------------------------------
 // Name: enterData
 // Desc: adds an item to the data set
 //------------------------------------------------------------------------------
 void KStats::enterData(const KNumber &data)
 {
     data_.push_back(data);
 }
 
 //------------------------------------------------------------------------------
 // Name: clearLast
 // Desc: removes the last item from the data set
 //------------------------------------------------------------------------------
 void KStats::clearLast()
 {
     if (!data_.isEmpty()) {
         data_.pop_back();
     }
 }
 
 //------------------------------------------------------------------------------
 // Name: sum
 // Desc: calculates the SUM of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::sum() const
 {
     KNumber result = KNumber::Zero;
     for (const KNumber &x : std::as_const(data_)) {
         result += x;
     }
 
     return result;
 }
 
 //------------------------------------------------------------------------------
 // Name: median
 // Desc: calculates the MEDIAN of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::median()
 {
     KNumber result = KNumber::Zero;
     size_t index;
 
     unsigned int bound = count();
 
     if (bound == 0) {
         error_flag_ = true;
         return KNumber::Zero;
     }
 
     if (bound == 1)
         return data_.at(0);
 
     // need to copy data_-list, because sorting afterwards
     QList<KNumber> tmp_data(data_);
     std::sort(tmp_data.begin(), tmp_data.end());
 
     if (bound & 1) { // odd
         index = (bound - 1) / 2 + 1;
         result = tmp_data.at(index - 1);
     } else { // even
         index = bound / 2;
         result = ((tmp_data.at(index - 1)) + (tmp_data.at(index))) / KNumber(2);
     }
 
     return result;
 }
 
 //------------------------------------------------------------------------------
 // Name: std_kernel
 // Desc: calculates the STD Kernel of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::std_kernel()
 {
     KNumber result = KNumber::Zero;
     const KNumber mean_value = mean();
 
     if (mean_value.type() != KNumber::TYPE_ERROR) {
         for (const KNumber &x : std::as_const(data_)) {
             result += (x - mean_value) * (x - mean_value);
         }
     }
 
     return result;
 }
 
 //------------------------------------------------------------------------------
 // Name: sum_of_squares
 // Desc: calculates the SUM of all values in the data set (each squared)
 //------------------------------------------------------------------------------
 KNumber KStats::sum_of_squares() const
 {
     KNumber result = KNumber::Zero;
 
     for (const KNumber &x : std::as_const(data_)) {
         result += (x * x);
     }
 
     return result;
 }
 
 //------------------------------------------------------------------------------
 // Name: mean
 // Desc: calculates the MEAN of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::mean()
 {
     if (data_.isEmpty()) {
         error_flag_ = true;
         return KNumber::Zero;
     }
 
     return (sum() / KNumber(count()));
 }
 
 //------------------------------------------------------------------------------
 // Name: std
 // Desc: calculates the STANDARD DEVIATION of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::std()
 {
     if (data_.isEmpty()) {
         error_flag_ = true;
         return KNumber::Zero;
     }
 
     return (std_kernel() / KNumber(count())).sqrt();
 }
 
 //------------------------------------------------------------------------------
 // Name: sample_std
 // Desc: calculates the SAMPLE STANDARD DEVIATION of all values in the data set
 //------------------------------------------------------------------------------
 KNumber KStats::sample_std()
 {
     KNumber result = KNumber::Zero;
 
     if (count() < 2) {
         error_flag_ = true;
         return KNumber::Zero;
     }
 
     result = (std_kernel() / KNumber(count() - 1)).sqrt();
 
     return result;
 }
 
 //------------------------------------------------------------------------------
 // Name: count
 // Desc: returns the amount of values in the data set
 //------------------------------------------------------------------------------
 int KStats::count() const
 {
     return data_.size();
 }
 
 //------------------------------------------------------------------------------
 // Name: error
 // Desc: returns the error state AND clears it
 //------------------------------------------------------------------------------
 bool KStats::error()
 {
     bool value = error_flag_;
     error_flag_ = false;
     return value;
 }