All Questions
Tagged with logarithm correlation
12
questions
0
votes
1
answer
537
views
How to deal with negative values after subtracting the background?
I am working with Luminex data and have a question regarding the treatment of negative values after subtracting the background average. Specifically, I would like to know if these negative values need ...
- 11
0
votes
1
answer
50
views
Should i make correlation matrix of (1) first difference logarithm, (2) logarithm or (3) the natural numbers?
I am currently working on a project where I am looking at how prices are affected by changes in the exchange rates. For an example, I want to see how a change in my currency (Norwegian Kroner) affects ...
- 1
22
votes
5
answers
6k
views
What is the intuitive meaning of having a linear relationship between the logs of two variables?
I have two variables which don't show much correlation when plotted against each other as is, but a very clear linear relationship when I plot the logs of each variable agains the other.
So I would ...
- 1,381
2
votes
0
answers
47
views
Bound for type of correlation measure
Assume you have a finite, discrete probability distribution for a joint random variable and such that $P(X=i,Y=j) = p_{i,j}$ for $i \in \{1, \dots, |X|\},j \in \{1, \dots, |Y|\}$. The marginal ...
- 33
0
votes
0
answers
727
views
Is this usage correct for using isometric log ratio [ILR] transform with counts data (compositional)?
If one wanted to construct a simple pairwise correlation matrix from an compositional data table using an ILR transform preprocessing step, would this usage violate any assumptions with the transform? ...
- 1,472
3
votes
1
answer
572
views
x is correlated with y but log(x) is uncorrelated with log(y)
I ran an experiment where I experimentally (randomly) manipulated $x$ to find out the effect on $y$. Both variables tend to have power law distributions, and this was indeed the case.
I ran some ...
- 31
0
votes
0
answers
118
views
Pearson correlation changes after transforming variables (time series, ARIMA) - what is wrong?
I have four variables (Y, X1, X2, X3). The original Y and original X1 both have positive trends and have a Pearson Correlation 0.845 (significantly positive correlation). Based on theories, the ...
- 71
2
votes
2
answers
1k
views
goodness of fit log transformed vs not log transformed
I have a relationship of two variables which is somehow log shaped. Now, I establish two models for this dataset, for one I log transform the dependent variable:
...
- 23
21
votes
1
answer
48k
views
do logs modify the correlation between two variables?
I am applying logs to two very skewed variables and then doing the correlation.
Before logs the correlation is 0.49 and after logs it is 0.9. I thought the logs only change the scale. How is this ...
- 537
2
votes
2
answers
2k
views
Use logarithmic or linear values when performing correlation and ANOVA?
The data was collected using a logarithmic scale: scores (explanatory variable) are collected with values from 0-5. A score of 3 is 10x the value of a score of 2.
I wasn't sure if using either the ...
- 63
13
votes
1
answer
43k
views
Why use logged variables?
Probably, this is a very basic question but I don't seem to be able to find a solid answer for it. I hope here, I can.
I'm currently reading papers as a preparation for my own master's thesis. ...
- 798
13
votes
2
answers
25k
views
Taking correlation before or after log-transformation of variables
Is there a general principle on whether one should compute pearson correlation for two random variables X and Y before taking their log transform or after? Is there a procedure to test which is more ...
- 3,293