Ma’ruza rejasi

Mashinali o’qitishda Logistik regressiya

Ma’ruza rejasi

• Logistik regressiya tushunchasi
• Logistik regressiya uchun model qurish
• Regression model koeffitsentlarini aniqlash
• Logistik regressiya uchun Cost funksiyasini hisoblash
• Logistik regressiya uchun Gradient Descent algoritmi
• Model aniqligini tekshirish

Logistik regressiya

Logistik regressiyaning maqsadi, har qanday klassifikatorda bo'lgani kabi, xususiyatlarda mavjud bo'lgan ma'lumotlardan foydalanib, ma'lum bir kuzatuv sinfini aniq bashorat qilish uchun ma'lumotlarni ajratishning ba'zi usullarini aniqlashdir.

Classification(Sinflashtirish)
Email: spam / spam bo’lmagan?
Online tanzaksiya: firibgarlik(Yes / No)?
Shish: zararli / xavfsiz
0: “Negative Class” (e.g., xavfli shish)
1: “Positive Class” (e.g., xavfsiz sish)
Shish o’lchami
chiquvchi qiymatni solishtish. Busag’a=0.5
agar , “y = 1” deb topiladi
agar , “y = 0” deb topiladi
Shish o’lchami
Xavfliligi?
(Ha) 1
(Yoq) 0
Sinflashtirish: y = 0 or 1
> 1 yoki < 0 bo’lishi mumkin
Logistik Regressiya:
Sigmoid funksiya
Logistik funksiya
Logistik Regressiya Modeli
Xoylaymizki
1
0.5
0

Qaror chegarasi (Decision boundary)

Logistik Regressiya
Logistik regressiya
Bashorat qilinadi “ “ agar
Bashorat “ “ agar
z
1
x1
x2
Decision Boundary
1
2
3
1
2
3
Bashorat “ “ agar
Chiziqli bo’lmagan decision boundaries
x1
x2
Bashorat “ “ agar
x1
x2
1
-1
-1
1
x1
x2
x1
x2
Ikkilik sinflashtirish
Multi-class sinflashtirish:
x1
x2
Sinf 1:
Sinf 2:
Sinf 3:
x1
x2
x1
x2
x1
x2
Multi-class sinflashtirish
Logistik regressiya uchun cost funksiyasi
Bu yerda hat doim y=0 yoki 1 bo’ladi.
parametrni aniqlash uchun:
Logistik regressiya uchun cost funksiyasi
Gradient Descent algoritmi
Kerak :
( optimallashguncha takrorlash )
takrorlash
Algoritm chiziqli regressiyaga o’xshagan !!!

Foydalanilgan adabiyotlar

Aurelian Geron, Hands on Machine Learning with Scikit-Learn Keras&Tensorflow // Second edition Concepts, Tools, and Techniques to Build Intelligent Systems, 2019, 510 pages
https://www.geeksforgeeks.org/ml-types-learning-supervised-learning/ https://www.guru99.com/unsupervised-machine-learning.html https://www.w3schools.com/python/python_ml_linear_regression.asp https://www.w3schools.com/python/python_ml_multiple_regression.asp https://www.w3schools.com/python/python_ml_polynomial_regression.asp https://www.mathworks.com/help/stats/regress.html