logistic regression - 피노텍 화요 스터디
TRANSCRIPT
![Page 1: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/1.jpg)
Machine LearningLogistic Regression
이도현Finotek Inc.
![Page 2: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/2.jpg)
- Logistic Regression = Classification
input
B
f(x)
A
![Page 3: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/3.jpg)
- Logistic Regression = Classification
input
0
f(x)
1
![Page 4: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/4.jpg)
- Logistic Regression = Classification
input
0
f(x)
1
![Page 5: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/5.jpg)
- 가설함수의 의미
h(x) 의 결과값=결과를 예측하는 값
![Page 6: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/6.jpg)
- 가설함수의 의미
비용 (Cost)=예측값 – 실제값
h(x) - y
![Page 7: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/7.jpg)
- 가설함수의 의미
h(x) = ax + b
![Page 8: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/8.jpg)
0 1
- 가설함수의 의미
![Page 9: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/9.jpg)
- 새로운 가설함수
![Page 10: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/10.jpg)
- 새로운 가설함수
0 < h(x) < 1
![Page 11: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/11.jpg)
- 새로운 가설함수
h(x) = 0.7, then y = 1
h(x) = 0.3, then y = 0
![Page 12: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/12.jpg)
- 새로운 가설함수
If h(x) >= 0.5 y = 1If h(x) < 0.5 y = 0
![Page 13: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/13.jpg)
- 새로운 가설함수
x >= 0 y = 1x < 0 y = 0
OX >= 0 -> y y =1
![Page 14: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/14.jpg)
- Cost Function 이란 ?
비용함수 =예측값과 실제값의 차이의 평균Mean of (h(x) – y)
![Page 15: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/15.jpg)
- Cost Function 이란 ?
비용함수의 값 =h(x) 의 값이 실제값 y 와 차이가 나면 날수록 커져야한다 .
![Page 16: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/16.jpg)
- Cost Function 란 ?
y = 0
h(x) = 0.7
![Page 17: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/17.jpg)
- Cost Function 이란 ?
![Page 18: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/18.jpg)
- Cost Function 이란 ?
![Page 19: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/19.jpg)
- Cost Function 이란 ?
![Page 20: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/20.jpg)
- Cost Function 이란 ?
![Page 21: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/21.jpg)
- Cost Function 이란 ?
![Page 22: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/22.jpg)
- Cost Function 이란 ?
![Page 23: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/23.jpg)
- Cost Function 이란 ?
![Page 24: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/24.jpg)
- Cost Function 이란 ?
![Page 25: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/25.jpg)
- Cost Function 이란 ?
![Page 26: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/26.jpg)
- Gradient Descent!
![Page 27: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/27.jpg)
- Gradient Descent!
![Page 28: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/28.jpg)
- Gradient Descent!
![Page 29: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/29.jpg)
- 예제
사람과 뱀을 구분하라
![Page 30: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/30.jpg)
- 예제
길이 (width) 높이 (height) y
30 166 1
34 183 1
203 23 0
40 192 1
199 30 0
36 177 1
150 19 0
33 154 1
190 40 0
166 30 0
90 10 0
사람 = 1, 뱀 = 0
![Page 31: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/31.jpg)
- 예제
사람 = 1, 뱀 = 0
![Page 32: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/32.jpg)
- 예제
사람 = 1, 뱀 = 0
![Page 33: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/33.jpg)
- Softmax Regression(= for Multivariable)
![Page 34: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/34.jpg)
- Softmax Regression(= for Multivariable)
![Page 35: Logistic Regression - 피노텍 화요 스터디](https://reader035.vdocuments.net/reader035/viewer/2022062401/58eceb691a28ab26308b461b/html5/thumbnails/35.jpg)
- 과제
길이 (width) 높이 (height) y
30 166 A
34 183 A
203 23 B
550 270 C
199 30 B
36 177 A
150 19 B
33 154 A
190 40 B
660 304 C
594 298 C
40 192 A
497 314 C
455 263 C
166 30 B
표준입출력을 사용해서 가로와 높이를 넣으면사람 (A), 뱀 (B), 코끼리 (C) 를 구분하는 프로그램을 작성하시오