# Questions tagged [log]

The tag has no usage guidance.

60 questions
Filter by
Sorted by
Tagged with
28 views

### Modelling exchange rates: how to log transform percentage changes?

I'm trying to model an exchange rate to test for extreme values. However, I have percentage changes from day to day. Given some changes are negative, I can't take the logarithm. Any idea how I could ...
21 views

### log regression - what is the last variable in this equation? it wasn't defined can this be the error term?

Can someone help me understand what ∆η_it is?
32 views

### Can I fit a Poisson model to ln transformed data? [closed]

This is my first question in stats Stack Exchange and I would say that it is an easy one, but hard to find around! I have a set of fish counts which should follow a Poisson Distribution (right ? ). ...
27 views

### Log-Log regression and cost function

I have made a very siple linear regression model having used log-log tranformation for the y and one of the independent variables: log(y)=B0+log(X1)B1+X2B2 where B0 is the intercept and B1,B2 the ...
60 views

### For lognormal distribution which one is preferred? Log 10 or Ln or Log 2?

I want to perform a linear regression analysis. The distributions of data for all continuous variables are not normal. The tail of graph is to the right and thre highest point of graph is due to the ...
86 views

### Why is the expected gradient of a density not parallel to the expected gradient of the log density?

I'm confused by a seemingly counter-intuitive property of the interaction between distributions, log transforms, expectations and gradients. Suppose I have some distribution over random variable $x$ ...
9 views

### log values in coxph model?

I have a data frame of gene expression values (sequencing). When I do CPM-normalization without doing log2, I get much "better" (lower) p-values compared to when I do log2-CPM. What is the ...
20 views

### Behaviour of likelihood ratio test as sample size increases

I know that the log likelihood statistic, i.e. $X^2=-2(LL_1 - LL_2)$ where $LL_1$ and $LL_2$ are the maximum log likelihoods of two models, one nested in the other, is asymptotically distributed as a ...
98 views

### Rare value prediction in Regression

Im working on a project which is to estimate blood pressure from independent variables. The problem I have is that the Blood Pressure data is gaussian in nature since most of the people are having ...
25 views

### Detect anomaly users who try to access too often based on the access log

Does anyone give me advice for statistically detecting anomaly users who try to log in our website too often? At first, the idea that came to my mind is to use Spike detection approaches or IQR ...
26 views

### Do I add both the new variable and the original variable to my log binomial model?

I'm calculating interaction indices for some variables in my model. I have an interaction between two variables (age (continuous) and hypertension (binary)), and I read in a similar publication that ...
41 views

### How do I interpret this interaction between a continuous variable and a binary variable from a log binomial model?

I'm new to modelling and not sure how to interpret this interaction for a results section. The model output tells me that the interaction between cancer (binary) and age (continuous - one year ...
26 views

### Interpretation of log-transformed regression (Y = LN(Y)) when the independent variable (X) is a percentage [duplicate]

First, I want to mention that I am not really experienced with statistics and thus I would kindly ask you to explain the answer to me like you would to a 5-year old. Secondly, I have read a lot of ...
66 views

### Log-Normalization of skewed data before feeding to neural network models ( autoencoders)

If your input data has few columns that are extremely skewed, It is well known that one would log normalize ( take log and then normalize or standardize) the data before passing to regression ...
52 views

### Should I convert the number after log transformation back to the original for calculating RMSE?

When I built the model, I applied the log transformation to all variables including the dependent variables. Now, I'm calculating the RMSE for the evaluation, and the result is in the log format, ...
68 views

### Interpretation Confidence interval including zero

I'm performing a negative binomial regression (xtnbreg in Stata). However, I found that the confidence interval of my regression includes zero. I have no clue how ...
138 views

### Interpret GLM log link coefficients

I am currently doing a college assignment in which I have a GLM model in the gaussian family with a log link. I would like to know what the impact per variable is. I know how to calculate the ...
52 views

### Is it correct to do stats in log transformed metabolomics data?

I have a dataset from targeted metabolomics analysis, the units I am working with are ng/ml[creatinine] (I use creatinine concentration to normalize the data since the samples are urine and can have ...
52 views

### Interpret log-linear with dummy variable

I have the following model: ln(y) = b0 + B1 X1 + B2 ln(X2) + B3 X3 My X1 is a dummy that can take the values 0, 1 and 2. The coefficient for the dummy 1 is -0,500 My question is how do i interpret ...
69 views

### How to interpret coefficient when the dependent variable is a percentage change?

I am having some trouble interpreting my regression output. My model is LN of transaction volume = alpha + $\beta_1$_RER + control variables RER is defined as the change in the average exchange rate ...
13 views

### Interpretation of log(1+x) variable with y in percentage

In std regression analysis, I'm wondering what the correct interpretation of a log (1+x) variable is when my y is in percentages. My x variable takes on values from 0-4, with the the majority of the ...
1k views

115 views

### Linear regression - Can I log transform dependent variable and one of the independent ones and keep the rest not transformed? [duplicate]

I have model where my dependent variable is Total money spend and then I have independent variable Income and some other ...
675 views

### Computing the Hessian of maximum log likelihood function

I am trying to find the Hessian matrix for the maximum log likelihood function given training data {(xi, yi)} for i=1:N with yi ∈ {+1, −1} for each i = 1, . . . , N for the function: When I try to ...
50 views

So my model has some high coefficients and i have many doubts how should I interpret them $LnHomii_t = 1.183 - 0.535 LnRendai_t + 4.46\times 10^6Escolai_t - 7.98\times 10^7BOLFAMi_t - 5.378Ginii_t + ... 0answers 64 views ### Log-log regression where variables are in terms of growth rate I would like to estimate elasticity of exchange rate on export. The specification takes the following form: $$Exp=\alpha+\beta_0REER+\beta_1GDP^{p}+\epsilon$$ where,$Exp$is export growth calculated ... 0answers 16 views ### Does log-transform independent variable actually help reducing absolute relative errors in regression? Based on my experience, I usually log-transform my target variable especially in cases dealing with price prediction. Mainly, it helps with the interpretability. However, I have seen some cases where ... 1answer 42 views ### Converting relative effect to absolute effect in log model I have the following model; log(daily sales) = intercept + B1*(event dummy) + error My response variable(daily sales) is basically a daily time series and 'event dummy' is an indicator variable ... 1answer 160 views ### Log-Log in panel data for multiple regression I'm using a model, for an article, with 6 independent variables. I used the logarithmic transformation of the dependent variable (Y) and 2 of the 6 independent variables. One of my professors said ... 1answer 68 views ### In OLS, while using log-log and linear-log transforamtions, is valid to transform some regressors only? In OLS I was wondering if it is valid to log-transform some regressors only. Specifically, continuous regressors, because it is advised not to transform binary or categorical variables. For instance, ... 1answer 1k views ### Interpreting adjusted R-squared of a log transformed regression model I am running a linear regression model where the dependent variable (Y) is log-transformed. I am struggling on how to interpret the adjusted R-squared of this log-transformed model that is meaningful. ... 1answer 136 views ### Odds ratio, Meta-analysis I have the following for the data for the meta-analysis: OR , standard errors, logged OR , variance of logged OR I have generated a forest plots first using "OR" with "variance of logged OR" using ... 0answers 117 views ### Interpreting forecast predictions of log transformed data Using the forecast function in R, I make a 1-step prediction for a log-transformed data set Y, ( Y = log(X) ). This prediction gives me a mean and a 95% prediction interval. How valid is this ... 0answers 17 views ### log model , per capita variabel? I have a question regarding statistics interpretation . As far as I know when I have two variables I can interpret the results as following: Y and X -- a one unit increase in X would lead to a β β ... 1answer 42 views ### Interpretation of Regression Coefficients with log transformation [closed] I am struggling to understand the interpretation of the regression coefficient in a log-log model, log-linear model and linear-log model. To give an example, let's assume that I have the following ... 1answer 2k views ### How to back-transform a log transformed regression model in R with bias correction I have created a model to predict the number of people with a certain characteristic (Y) based on predictor variables$X_1$,$X_2$,$X_3$,$X_4\$. The model is a multiple linear regression and both the ...
I'm estimating demand and calculating price elasticity using logistic regression. In logistic regression with level price, elasticity is $$\alpha*price*(1-share)$$ while if one uses log of price, ...