Questions tagged [logarithm]
The logarithm of a number is the power to which the base must be raised to get the number.
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Rescale measures of association for meta-analysis (e.g., log-transformed independent variables)
I am carrying out a meta-analysis of studies evaluating the association between blood levels of specific environmental pollutants and health outcomes (binary).
Some studies reported OR/RR/HR for ...
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log transform left data in r
I am having trouble finding the transformation operation for left/negatively skewed data. The catch? All of my values are between 0 and 1. As such, trying the standard log10 transformation command ...
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log transformation for paired t test
If my difference scores are not normally distributed - and I want to do a parametric paired t-test - do I:
log transform the the original scores and perform a paired t-test on these scores
log ...
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What are alternatives to broken axes?
Users are often tempted to break axis values to present data of different orders of magnitude on the same graph (see here). While this may be convenient it's not always the preferred way of displaying ...
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Why are log probabilities useful?
Probabilities of a random variable's observations are in the range $[0,1]$, whereas log probabilities transform them to the log scale. What then is the corresponding range of log probabilities, i.e. ...
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Rejection sampling method in tail of truncated exponential distribution (answered)
See edit below as question has been answered.
I want to sample from an exponential distribution with parameter $\lambda>0$ truncated in the tail between $a>0$ and $b>0$, such that $b>a$, ...
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Back Transforming log-log Model for Prediction
I have a model that is log-log and I would like to make raw predictions of $Y$ with it:
$\ln(Y) = B_0 + B_1\ln(X)$
All answers and articles I have found concerning back transforming for prediction ...
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How to do log subtract (just like logsumexp) with probabilities? [closed]
To subtract a small probability from another, this answer has constraint on log probabilities l1 > l2: Subtracting very small probabilities - How to compute? but I need a function that works for ...
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Both quadratic and linear term are insignificant
I am trying to fit a model which has age as a control variable and mental health score as my dependent variable. I centered the age because 0 is not meaningful in my analysis. I tried age, age^2, log(...
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Interpreting log transformed variables in a regression [duplicate]
I am very confused about the interpretation of log transformed variables in a regression. For example, I have a log-level model with a B0=4.95 and B1=-1.07. So my model would be log(y)=4.95 - 1.07X. ...
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Is the exponent of the MAD (Median Absolute Deviation) of log transformed Data measuring the relative distance from median in the untransformed data?
I want to confirm whether taking the Exponent of the MAD of Log Transformed Data gives me a measure of relative distance from median of the original untransformed data.
So say I have a MAD of 0.2 for ...
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Transforming a natural log of a variable into the original variable
I am using a replication dataset for a research, and one variable (GDP per capita) is included in the dataset only as a natural logarithm. Is it possible to transform the ln(GDP per capita) back into ...
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How to log transform a small percentage value?
My independent variable is interest rate, which is small positive variable(less than 1). When I log transform the values, they turn negative because the values are smaller than 1. What is the solution?...
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How to interpret a regression table with logged DVs?
I'm writing a research paper and am using R for my quantitative analysis. I'm using OLS regression and have needed to perform a log transformation on my dependent variables for linearity however I don'...
Bella
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Can we find a variance formula in terms of the log of the density? ($f(t) = e^{u(t)}$, need variance in terms of $u$)
Given a density $f(t)$, say over $t\in \mathbb{R}^n$ absolutely continuous with Lebesgue measure. Write $u(t) = \log(f(t))$ taking values in $[-\infty, \infty)$ so $f = \exp(u)$.
Can we find a general ...
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