Linked Questions

22
votes
2answers
28k views

Transforming proportion data: when arcsin square root is not enough

Is there a (stronger?) alternative to the arcsin square root transformation for percentage/proportion data? In the data set I'm working on at the moment, marked heteroscedasticity remains after I ...
3
votes
4answers
3k views

Appropriate data transformation

I have two dependent variables y1 and y2 with highly skewed distributions. In order to do ANOVA, I was trying to transform the ...
4
votes
2answers
2k views

Regression: Scatterplot with low R squared and high p-values

Based on three datasets, I have produced the scatterplot below in Python: I am trying to fit a line on each dataset, but when I check the metrics this is what I get: Set 1 (red): $R^2$=0.002, p-...
2
votes
2answers
2k views

Plot a highly skewed dataset

I have a dataset that contains music genres, songs and a "speechiness" rate. An example looks like this: ...
1
vote
3answers
1k views

Transformation of specific data

I need help with data transformation. In the picture below the upper left picture shows the histogram of the variable V6. Because it is so right-skewed I tried 3 forms of transformation but none of ...
2
votes
3answers
805 views

Forecasting daily data with zeros in Python

I'm currently testing some forecasts on daily sales quantities. However, out of ~2000 observations I have 16 zeros. How should I approach this? It's mainly Sundays and holidays that holds zero as ...
2
votes
2answers
225 views

How to back transform a folded root?

I have some data where the response variable is a proportion, and I am experimenting with transformation using Tukey's family of folded powers, $f(p) = p^\lambda - (1 - p)^\lambda$, with values of $\...
1
vote
3answers
101 views

Working with ratios: standardizing problem

I have a dataset, let's say of counts of apples and oranges. I would like to have a metric that equally reflects the ratio of apples to oranges but if I simply use the ratio: apple count + 1 : ...
1
vote
1answer
197 views

Percentage difference of percentages

Basic question - we have data representing the average performance of two sets of hospitals on a quality measure. The denominator for each set is different. Is it acceptable to calculate percentage ...
1
vote
1answer
128 views

How can I interpret the coefficient of a logit transformed explanatory variable in linear regression?

I fit a linear regression model with continuous response. One of my predictor variables is given in percentage. So I transformed the predictor with logit transformation. My question is how can I ...
0
votes
1answer
152 views

Model proportions as independent variable for binary outcome

I've binary (disease) outcome: 0, 1 with certain independent variables in proportions, and other covariates as - age, sex. There are Packages that model proportions as outcome variable but not other ...