add: Linear Regression

math/Linear_Regression.cpp

@@ -0,0 +1,116 @@
+#include <iostream>
+#include <cmath>
+#include <vector>
+
+/*pilihan pertama buat dalam 1 void function 
+pilihan kedua adalah buat dalam beberapa void
+ function di ikuti dengan penggunaaan struct
+*/
+// sumber soal: https://mathcyber1997.com/regresi-linear-sederhana/ - > nomor 1 
+struct DataStatistic{
+    float SumX;
+    float SumY;
+    float Xsquared;
+    float Ysquared;
+    float multiply;
+};
+void Squared(std::vector<float>& independen, std::vector<float>& dependen,DataStatistic &stats){
+    // bisa menggunakan pow bawaan STL cmath atau langsung dengan metode manual
+    //contoh menggunakan pow
+    float SumSquared = 0;
+    float XSquared;
+    for(int i = 0; i <= independen.size() - 1; i++){
+        XSquared = pow(independen[i],2);  // variabel ,pangkat
+        SumSquared += XSquared;
+    }
+    stats.Xsquared = SumSquared;
+    std::cout << "Hasil X squared " << stats.Xsquared << std::endl;
+    //contoh metode manual
+    float SumYSquared = 0;
+    float Ysquared;
+    for(int i = 0; i <= dependen.size() - 1;i++){
+        Ysquared = dependen[i] * dependen[i];
+        SumYSquared = SumYSquared + Ysquared; // bisa juga dengan +=
+    }
+    stats.Ysquared = SumYSquared;
+    std::cout << "Hasil Y squared " << stats.Ysquared << std::endl;
+
+}
+void sum(std::vector<float>& independen, std::vector<float>& dependen,DataStatistic &stats){
+    float sumx = 0;
+    float sumy = 0;
+    for(int i = 0; i <= independen.size() - 1;i++){
+        // karena panjang data sama maka cukup 1 for loop
+        sumx += independen[i];
+        sumy += dependen[i];
+    }
+    stats.SumX = sumx;
+    stats.SumY = sumy;
+    std::cout << "SumX: " << stats.SumX << std::endl;
+    std::cout << "SumY: " << stats.SumY << std::endl;
+}
+void multiple(std::vector<float>& independen, std::vector<float>& dependen,DataStatistic &stats){
+    float multiply;
+    float SumMultiply = 0;
+    for(int i = 0; i <= independen.size() - 1; i++){
+        multiply = independen[i] * dependen[i];
+        SumMultiply += multiply;
+    }
+    stats.multiply = SumMultiply;
+    std::cout << "Hasil Kali: " << stats.multiply << std::endl;
+}
+
+
+void LinearRegression(std::vector<float>& independen, std::vector<float>& dependen,DataStatistic &stats){
+    double SumSquareXX;
+    double SumSquareXY;
+
+
+    SumSquareXY = stats.multiply - ((stats.SumX * stats.SumY)/ independen.size());
+    SumSquareXX = stats.Xsquared - (pow(stats.SumX,2)/independen.size());
+    // print untuk memastikan hasil nya benar
+    std::cout << "Hasil SumSquareXY: " << SumSquareXY << std::endl;
+    std::cout << "Hasil SumSquareXX: " << SumSquareXX << std::endl;
+
+
+    // b0 = intercept
+    // b1 = gradient atau slope
+
+    double Slope,Intercept;
+
+    Slope = SumSquareXY / SumSquareXX;
+
+    Intercept = (stats.SumY - (Slope * stats.SumX)) / independen.size();
+
+    std::cout << "Model Regresi Linear = " << Intercept << " + " << Slope << "x ";
+}
+
+int main(){
+    DataStatistic stats;
+    std::vector<float> independen = {1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2};
+    std::vector<float> dependen = {8.1,7.8,8.5,9.8,9.5,8.9,8.6,10.2,9.3,9.2,10.5};
+    int count,IndependenValue,DependenValue;
+
+    //karena tahap production kita akan memakai data yg sudah ada saja
+    //anda dapat men uncomment code dibawah dan menghapus data pada vector dependen dan dependen
+
+
+
+    // std::cout << "Masukkan panjang data: ";
+    // std::cin >> count;
+    // for(int i = 0; i <= count - 1; i++){
+    //     std::cout << "Masukkan data x: ";
+    //     std::cin >> IndependenValue;
+    //     independen.push_back(IndependenValue);
+    //     std::cout << "Masukkan data y: ";
+    //     std::cin >> DependenValue;
+    //     dependen.push_back(DependenValue);
+    // }
+    float sum_x = independen.size();
+    float sum_y = dependen.size();
+    sum(independen,dependen,stats);
+    Squared(independen,dependen,stats);
+    multiple(independen,dependen,stats);
+    LinearRegression(independen,dependen,stats);
+    std::cin.get();
+}

math/z_score.cpp

@@ -1,69 +0,0 @@
-#include <iostream>
-#include <vector>
-#include <cmath>
-
-
-bool Verification(std::vector<int>& data,int &x){
-    for(int i = 0;i <= data.size() - 1; i++){
-        if(x == data[i]){
-            return true;
-        }
-    }
-    return false;
-}
-
-void Z_Score(std::vector<int>& data,int &x){
-    //mean
-    int resultMean;
-    int Sum = 0;
-    for(int i = 0; i <= data.size() - 1;i++){
-        Sum += data[i];
-    }
-    resultMean = Sum / data.size();
-    std::cout << "Nilai rata-rata: " << resultMean << std::endl;
-
-    //standart deviation
-    int denominator = data.size() - 1;
-    int numerator;
-    float Standar_Dev;
-    float sum_numerator = 0;
-    for(int i = 0; i <= data.size() - 1;i++){
-        int numerator = sqrt((data[i] - resultMean) * (data[i] - resultMean)); //sqrt(pow((data[i] - mean))); 
-        sum_numerator += numerator;
-    }
-
-    Standar_Dev = static_cast<double>(sum_numerator) / denominator;
-    std::cout << "nilai Standar Deviation: " << Standar_Dev << std::endl;
-
-
-
-    // Z score
-    double score;
-    score = (x - resultMean) / Standar_Dev;
-    std::cout << "Nilai Z-Score: " << score << std::endl;
-}
-int main(){
-    int value,count,x;
-    std::vector<int> data;
-    std::cout << "Masukkan panjang data: "; //masukkan panjang data
-    std::cin >> count;
-
-    for(int i = 0; i <= count - 1; i++){ // for untuk memasukkan data satu per satu
-        std::cout << "Masukkan data ke " << i + 1 << ": ";
-        std::cin >> value;
-
-        data.push_back(value); //masukkan data yang di input di variabel value;
-    }
-    std::cout << "Masukkan nilai data(x): ";
-    std::cin >> x;
-
-    if(Verification(data,x)){
-        std::cout << "Nilai yang anda masukkan sudah benar! " << std::endl;
-    }else{
-        std::cout << "data yang anda masukkan salah! \n";
-        std::cout << "Masukkan nilai kembali: ";
-        std::cin >> x;
-    }
-    Z_Score(data,x);
-
-}