# Linked Questions

1answer
6k views

### How to perform boxcox transformation on data in R tool [duplicate]

Possible Duplicate: How should I transform non-negative data including zeros? Error in boxcox.default(y ~ x) : response variable must be positive I want to perform box cox transformation on ...
0answers
2k views

### How to handle data which contains 0 in a log transformation regression using R tool [duplicate]

Possible Duplicate: How should I transform non-negative data including zeros? I want to perform log transformation regression in R tool but the problem is that I don't know how to handle ...
0answers
2k views

### Log transform with 'zero' values [duplicate]

I am doing some explorative work on two large datasets. One from 2001 and one from 2018. The dataset consists of measured soil-parameters and it contains lots of zero's. From the transformations ...
1answer
318 views

### How to preserve points near zero when taking logs? [duplicate]

Possible Duplicate: How should I transform non-negative data including zeros? I have a question: Suppose we have a data point $(0,10)$. We then convert to a log scale. Excel gets rid of this ...
0answers
183 views

### Data-transformation of data with some values = 0 [duplicate]

Possible Duplicate: How should I transform non-negative data including zeros? I want to log-transform some of my data because the Levene's homogeneity of variances test rejected the null ...
0answers
142 views

### What is the best mathematical transformation for a variable with many zero values? [duplicate]

Possible Duplicate: How should I transform non-negative data including zeros? I have a continuous variable that has many zeros values and is NOT normal, so I can't use parametric statistics on it....
0answers
53 views

### Natural logarithm transfomation and zeroes [duplicate]

I am using Stata 13 to estimate a simple regression. Given a rather positive skew of a few of my covariates, I figured to ln-transform the variables. However, I have a substantial amount of zeroes in ...
0answers
42 views

### Log transform dependent variable [duplicate]

I have a continuous dependent variable which has a somewhat skewed distribution and hence I want to apply a log transform to it. But the problem is that the target variable can have negative values. ...
0answers
40 views

### How to adjust for a continious variable when the value 0 is distinctly different from the others? [duplicate]

Lets say I want to regress a variable on a covariate which has distinct value zero but the all other values are following some smooth function? It could be e.g. Years of beeing a mom (once you are a ...
5answers
21k views

### How small a quantity should be added to x to avoid taking the log of zero?

I have analysed my data as they are. Now I want to look at my analyses after taking the log of all variables. Many variables contain many zeros. Therefore I add a small quantity to avoid taking the ...
8answers
10k views

### Rigorous definition of an outlier?

People often talk about dealing with outliers in statistics. The thing that bothers me about this is that, as far as I can tell, the definition of an outlier is completely subjective. For example, ...
2answers
38k views

### Regression: Transforming Variables

When transforming variables, do you have to use all of the same transformation? For example, can I pick and choose differently transformed variables, as in: Let, $x_1,x_2,x_3$ be age, length of ...
5answers
15k views

### What other normalizing transformations are commonly used beyond the common ones like square root, log, etc.?

In the analysis of test scores (e.g., in Education or Psychology), common analysis techniques often assume that data are normally distributed. However, perhaps more often than not, scores tend to ...
3answers
24k views

### How should you handle cell values equal to zero in a contingency table?

How should you deal with a cell value in a contingency table that is equal to zero in statistical calculations? (Note that such a value can be structural, i.e., it must be zero by definition, or ...
4answers
18k views

### How to avoid log(0) term in regression

I have following simple X and Y vectors: > X  1.000 0.063 0.031 0.012 0.005 0.000 > Y  1.000 1.000 1.000 0.961 0.884 0.000 > > plot(X,Y) I ...

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