regression

How do I fix the unrecognized object error in Stargazer with a dynlm model?

假如想象 提交于 2021-02-20 19:01:47
问题 I calculated a dynlm model and now want to get stargazer to export that. However, stargazer does not return any output, instead gives me the Unrecognized object type Error. I already checkd if dynlm objects were supported by stargazer and according to the package page it is. Anyone have any idea what I'm getting wrong here? I know how to export the output with stargazer, but in this case it doesn't even show me the results inside of R. This is the model I used and the stargazer command, which

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让人想犯罪 __ 提交于 2021-02-20 11:56:03
pa 2018-1-14 谷歌家面的是product analyst,一开始说是general hire,但好像面的时候直接见到了hardware team的一个年轻hiring manager,所以应该就是直接面那个组了。 一开始一轮电面,是个youtube的老印面的,主要是问简历,让挑一个觉得最满意的项目介绍一下,中间问了一些关于 Selection bias,怎么sampling之类的问题 ,然后问了一个sql,记不太清了,大致是先按照一个feature来Aggregate一个table,然后找出count最大的那个feature值对应的所有人,其实就是group by跟subquery的合用,然后问为什么不直接用order by,然后limit 1来找最大值,当然是回答说最大值有可能有很多个。 onsite四个人,两个是hardware team member,问的大都是关于组里做的工作,怎么去检测用户喜欢喜欢google手机硬件和软件的更新之类的。另外两个是别的组的analyst,大体是先简单问简历,然后问一个中等难度的Sql题,最后问一个他们领域的实验设计和建模题, 比如一个新游戏出来了,怎么去估计下载量,一个新软件更新了,怎么衡量这个更新对软件用户使用的影响 ,应该大体是考察你的逻辑能力和能不能在有限的时间内尽可能多地想到更多多的影响因素

logistic regression 最基础的分类算法

只愿长相守 提交于 2021-02-19 20:54:55
介绍 logistic regression是一种最基本的分类算法。它的模型为 ,其中 。 其代价函数 。 对于二分类问题,y的取值为0和1,这里,我们设定 为y=1概率。当其大于等于0.5时,我们预测结果为1,当其小于0.5时,我们预测结果为0。 使用梯度下降算法 迭代公式: 其中 。推导过程见下图。 矢量化表达: 。 来源: oschina 链接: https://my.oschina.net/u/4279696/blog/3979639

分类---Logistic Regression

走远了吗. 提交于 2021-02-19 17:11:46
一 概述 Logistic Regression的三个步骤 现在对为什么不使用均方误差进行分析(步骤二的) 由上图可以看出,当距离目标很远时,均方误差移动速率也很慢,不容易得到好的结果。 Discriminative(Logstic) v.s. Generative(Gaussion) 两种方法的model是一样的,训练的数据是一样的,但是找出来的参数不一样!!! 通常来说Discriminative的性能要比Generative要好 ,但是Generative也有自己的特色。 二 多分类 三 Logistic Regression 的局限 还可以使用另一种转换方式:Cascading logistic regression models就是一种转换的普适方法。 参考:http://speech.ee.ntu.edu.tw/~tlkagk/courses/ML_2016/Lecture/Logistic%20Regression%20(v3).pdf 来源: oschina 链接: https://my.oschina.net/u/4358782/blog/3884951

pytorc人工神经网络Logistic regression与全连接层

ⅰ亾dé卋堺 提交于 2021-02-19 12:09:18
//2019.10.08 神经网络与全连接层 1、logistics regression 逻辑回归的思想是将数据利用 激活函数sigmoid函数转换为0-1的概率 ,然后定义一定的阈值0.5,大于阈值则为一类,小于阈值则为另一类。它主要用来解决的是二分类问题,也可以通过一定的变形解决多分类的问题。 2、对于逻辑回归其实质是分类算法,为什称之为回归, 主要是因为其优化的函数类似于回归问题的loss函数,而将其称之为逻辑主要是因为利用了sigmoid函数。 图 3、回归问题和分类问题的loss函数是不一样: (1)回归问题:MSE (2)分类问题: 1)MSE(P) 2)cross entropy loss 3)Hinge Loss 图 4、 cross entropy loss交叉熵 :主要是指整体预测的不确定性,即熵的概念,熵的值越大,说明其确定性越低,概率分布越接近;熵的值越小,说明确定性越高,概率预测分布相差越大,越逼近极端的0或者1。 图123 5、 交叉熵函数cross_entropy=softmax+log+null_loss函数 图 6、激活函数主要有以下几种: sigmoid函数、tanh函数、Relu函数,改进版Relu函数,selu函数,softplus函数 7、一个神经网络层结构的搭建组成具体如下所示: 来源: oschina 链接: https://my

Categorical and ordinal feature data difference in regression analysis?

走远了吗. 提交于 2021-02-19 05:18:09
问题 I am trying to completely understand difference between categorical and ordinal data when doing regression analysis. For now, what is clear: Categorical feature and data example: Color: red, white, black Why categorical: red < white < black is logically incorrect Ordinal feature and data example: Condition: old, renovated, new Why ordinal: old < renovated < new is logically correct Categorical-to-numeric and ordinal-to-numeric encoding methods: One-Hot encoding for categorical data Arbitrary

Categorical and ordinal feature data difference in regression analysis?

被刻印的时光 ゝ 提交于 2021-02-19 05:15:49
问题 I am trying to completely understand difference between categorical and ordinal data when doing regression analysis. For now, what is clear: Categorical feature and data example: Color: red, white, black Why categorical: red < white < black is logically incorrect Ordinal feature and data example: Condition: old, renovated, new Why ordinal: old < renovated < new is logically correct Categorical-to-numeric and ordinal-to-numeric encoding methods: One-Hot encoding for categorical data Arbitrary

Categorical and ordinal feature data difference in regression analysis?

谁说胖子不能爱 提交于 2021-02-19 05:15:46
问题 I am trying to completely understand difference between categorical and ordinal data when doing regression analysis. For now, what is clear: Categorical feature and data example: Color: red, white, black Why categorical: red < white < black is logically incorrect Ordinal feature and data example: Condition: old, renovated, new Why ordinal: old < renovated < new is logically correct Categorical-to-numeric and ordinal-to-numeric encoding methods: One-Hot encoding for categorical data Arbitrary

Linear Regression prediction in R using Leave One out Approach

∥☆過路亽.° 提交于 2021-02-18 19:52:01
问题 I have 3 linear regression models built using the mtcars and would like to use those models to generate predictions for each rows of the mtcars tables. Those predictions should be added as additional columns (3 additional columns) of the mtcars dataframe and should be generated in a for loop using the leave one out approach. Furthermore predictions for model1 and model2 should be performed by "grouping" the cyl numbers whiles predictions made with the model 3 should be accomplished without

Linear Regression prediction in R using Leave One out Approach

寵の児 提交于 2021-02-18 19:51:34
问题 I have 3 linear regression models built using the mtcars and would like to use those models to generate predictions for each rows of the mtcars tables. Those predictions should be added as additional columns (3 additional columns) of the mtcars dataframe and should be generated in a for loop using the leave one out approach. Furthermore predictions for model1 and model2 should be performed by "grouping" the cyl numbers whiles predictions made with the model 3 should be accomplished without