毫升 |线性回归与逻辑回归
线性回归是一种基于监督回归算法的机器学习算法。回归基于自变量对目标预测值进行建模。它主要用于找出变量之间的关系和预测。不同的回归模型基于因变量和自变量之间的关系类型、它们正在考虑的以及使用的自变量的数量而有所不同。
逻辑回归基本上是一种监督分类算法。在分类问题中,目标变量(或输出)y 对于给定的一组特征(或输入)X 只能取离散值。
Linear Regression | Logistic Regression |
---|---|
Linear Regression is a supervised regression model. | Logistic Regression is a supervised classification model. |
In Linear Regression, we predict the value by an integer number. | In Logistic Regression, we predict the value by 1 or 0. |
Here no activation function is used. | Here activation function is used to convert a linear regression equation to the logistic regression equation |
Here no threshold value is needed. | Here a threshold value is added. |
Here we calculate Root Mean Square Error(RMSE) to predict the next weight value. | Here we use precision to predict the next weight value. |
Here dependent variable should be numeric and the response variable is continuous to value. | Here the dependent variable consists of only two categories. Logistic regression estimates the odds outcome of the dependent variable given a set of quantitative or categorical independent variables. |
It is based on the least square estimation. | It is based on maximum likelihood estimation. |
Here when we plot the training datasets, a straight line can be drawn that touches maximum plots. | Any change in the coefficient leads to a change in both the direction and the steepness of the logistic function. It means positive slopes result in an S-shaped curve and negative slopes result in a Z-shaped curve. |
Linear regression is used to estimate the dependent variable in case of a change in independent variables. For example, predict the price of houses. | Whereas logistic regression is used to calculate the probability of an event. For example, classify if tissue is benign or malignant. |
Linear regression assumes the normal or gaussian distribution of the dependent variable. | Logistic regression assumes the binomial distribution of the dependent variable. |