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Questions tagged [probability-density]

In probability theory, the density of a random variable is a function that describes the relative likelihood for this random variable to take on a given value. DO NOT CONFUSE THIS TAG WITH 'PDF': Adobe's file format.

Overview

From wiki:

In probability theory, a probability density function (pdf), or density of a continuous random variable, is a function that describes the relative likelihood for this random variable to take on a given value. The probability for the random variable to fall within a particular region is given by the integral of this variable’s density over the region. The probability density function is nonnegative everywhere, and its integral over the entire space is equal to one.

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Tag Usage

  • DO NOT CONFUSE THIS TAG WITH : Adobe's file format.

  • Questions on should be about implementation and programming problems, not about the statistical or theoretical properties of the technique. Consider whether your question might be better suited to Cross Validated, the StackExchange site for statistics, machine learning and data analysis.

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density plot shows fringes between points (R ggplot2)

Hi my density plot shows fringes/dips between points when there are only several points, see this picture: http://www.imagesup.net/?di=3141413124212 # show fringes test = as.data.frame( sample(0:5,1000,replace=T) ) colnames(test) =…
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Given a uniform distribution of a variable, use a function of random variables to plot the probability density function MATLAB

I have a question about using MATLAB to find the probability density function. The question is about the range of a cannon projectile with gravity, g = 9.8 m/s, and velocity, v = sqrt(980) m/s. The angle, theta, is a uniformly distributed random…
azumakazuma
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How to plot a distribution based on moments

I am wondering how, in Matlab, to plot a continuous pdf with the following information? mean=-0.3731 standard deviation= 5.6190 skewness=-3.0003 kurtosis=13.1722 or alternative how do I plot a continous pdf that is not normal? (like it is skewness…
user1664484
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How to get random item by priority from several arrays that could be empty

I want to randomly select a single item out of three lists, where each list represents a different probability of selection. I have three lists (can be also 3 arrays): high, mid, and low "priority". I want to choose one item from those three lists…
yzahavi
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MATLAB: Pricing a digital option, Monte Carlo vs. explicit integral formula?

I am stuck with the following problem using MATLAB: Let Z be lognormally distributed such that ln Z has mean m and variance w. Let eta be a negative number and c a positive constant. I am trying to compute the expected value (let I(Z<=c) denote the…
Tim
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Desired probability distribution

I have a data "zcosmo" that follows a certain distribution. It has many fluctuations (i.e it increases slightly at some point and then flattens etc, but overall it increases from 0 to 0.5). So I fit the data using a function that follows the…
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Density Graph for Chi Square in R

I'm trying to plot in R the graph of the density function of a Chi-Squared distribution with 28 df being the x higher to 7.5. Until now I got this from what I've been able to gather around: x <- pchisq(7.5, 28, lower.tail=FALSE) hist(x,…
Strinnityk
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Fit a parametric density to an constant piecewise Function in R, argument is missing error

Suppose somebody draw me an histogram and I want to smooth it, and get the smoothed function. Is their a way to do so in R? (The histogram is not coming from data, so kernel density estimators don't seem adapted. Please tell me if you think I am…
Mothas
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error of ploting pdf, cdf and quantile functions of truncated gamma distribution in R

After searching in the forum, I did not find similar questions. If I missed it, please let me know. I would really appreciate. I need to plot pdf , cdf, and quantile function of a truncated gamma for any given shape and scale values in R . But, I…
user3440244
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Random Variables Matlab

I have a Random Variable X that has the following probability density function as follows: X/25, 0 <= x <= 5 2/5-x/25, 5 <= x <= 10 0, otherwise I am trying to input this into matlab but I can't seem to find documentation on how to do this. Any…
OuOyeah
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How to plot to describe the density characteristics of a dataset?

I have datasets which consist of 263 users. It has the following data frame structure: userID bookmarkID tagID value 1 52 101 1 1 114 154 1 2 127 14 1 4 114 4 1 For each user, I calculate the value of a variable representing…
CyberPlayerOne
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How to determine high and low threshold value of two matrixes from mean and standard deviation

I have two matrixesthat belongs gaussian distribtion.The size are 3x3. Now, I want to estimate up and down threshold of their matrixes. I denote mean and standard deviation of each matrix is μ1;μ2 and σ1;σ2. The high and low threshold…
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Plotting two different distribution functions in R. Getting axis withing positive range of values

I was following this https://stackoverflow.com/a/3542115/3483997 approach in order to get 2 histograms (with different populations) integrated in the same data-frame. ROS_SPITFIRE <- data.frame(length = rnorm(100, 0.76406353,…
eFF
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Why does my code generate the Cumulative distribution function (CDF) greater than 1?

I want to plot Cumulative distribution function (CDF) of a set of values, Z using MATLAB. When I use the following code, the CDF would not be between 0 and 1! I would appreciate if you could help me. function plot_cdf(Z) numberbin=100; [n,x]…
Alex
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multivariate gaussian probability density function python on Mac

I'm unable to use SciPy and its modules for calculating the probability density function of a multivariate Gaussian distribution. I know that such modules exist, but I'm unable to use them (I can't even import scipy: I get the message: ImportError:…
user3431370
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