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0
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0answers
7 views

Tendency tags based on series of numbers

I am trying to create tendency tags based on historic data. Ie, I have the following series always ordered in time: [w,x,y,z] where: ...
1
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2answers
29 views

Can you compare probabilities of an epidemic by knowing R0 values?

In comparing two diseases with different basic reproduction numbers (R0), is it possible to use the R0 values to calculate the probability of an epidemic spread through a population? For example, if ...
0
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0answers
21 views

How do I write a function to draw histogram in R? [migrated]

I want to write a function that takes in the variables from a data frame as arguments and prints the corresponding histogram for that variable in R. I have been trying to make use of hist() function ...
-3
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0answers
19 views

Model functions of Bates and Watts?

Bates and Watts (1988) is often referred in my lecture notes of nonlinear regression. Does their book include some sort of list of basic exponential and logarithmic model functions. Simple ...
0
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0answers
15 views

Why SVM with RBF is similar to KNN with prototypes search?

I explored similar questions and everything I can see is that both kNN and RBF are non-parametric methods to estimate the density of probability of your data. However, I am not sure if this has ...
2
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2answers
34 views

What is this formula?

i have been asked to plot a graph of the residuals from the following formula: |y(hat)/y|-1 they said that it was MAPE but i have the formula for MAPE as: ...
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0answers
22 views

How can you cluster a set of functions with unknown functional forms?

Say you've $N$ functions $f_N(x)$ defined on a regular grid $x$. You don't know the form of $f(x)$, you've only got several realizations of it. The different functions are related to each other ...
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0answers
14 views

Web page scoring function based on readability (LIX)

I'm creating a scoring system for web pages based on their level of readability using LIX. A selection of pages from a web site are crawled and given a score. Besides average and median, what ...
0
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1answer
41 views

Correct notation wrt. uniform distribution

Assume that I have a discrete set $L$ and a transformation $\phi: L \rightarrow [0,1]$ that normalizes set $L$ such that now values belonging $L$ are uniformly distributed among the unit interval. ...
0
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0answers
21 views

How to represent this problem in a useful way?

How can I represent this problem as a function. Bear with me because it may seem odd. Say, for example I make cakes. There are 30 variations of cake in one batch. For each batch there are 19 luxury ...
0
votes
1answer
49 views

Generating functional-form PDF from Max Likelihood Estimation

For the purpose of this question, please consider me a stats newbie. I'm working on a (very fun!) research project which involves estimating a pdf of "personal values" -- i.e. how much a certain ...
2
votes
1answer
54 views

Given the distribution of a variable X, what is the distribution of f(X)?

Suppose I know the mean and standard deviation of a (roughly) normally distributed variable x. Is there any way for me to calculate the mean and standard deviation of f(x)? The particular problem I ...
0
votes
1answer
62 views

dealing with exponentials in python - infinities and overflows [duplicate]

In a machine learning algorithm that I'm using, I need to get the exponential values of something in one of the steps. This is the step that I'm dealing with right now: I've already got all the ...
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0answers
27 views

Is $Max${$F(X),G(Y)$} necessarily a distribution function?

If $F(X)$ and $G(Y)$ denote two distribution functions, then is $Max${$F(X),G(Y)$} necessarily a distribution function as well?
0
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0answers
35 views

How to interpret basis function that yields vector in machine learning algorithm?

I'm struggling to understand what $\phi(x_{N+1})$ is in this excerpt of an algorithm (namely Linear Bayesian Regression embedded in other algorithm): $c_i = \gamma_i / \sum^L_{j} \gamma_j$ ...
0
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0answers
20 views

Rearranging 2 discriminant function to solve for 1 parameter (to derive a decision boundary)

I have a task where I want to classify patterns from 2 classes where the samples are drawn from a bivariate Gaussian distribution. I use the 2 discriminant functions ($g_1$ and $g_2$) to classify the ...
8
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2answers
183 views

How to properly handle Infs in a statistical function?

Suppose I have a function such like: f <- function(x){ exp(x) / (1 + exp(x)) } it's supposed to work for any real value of x, but actually it returns NaN ...
1
vote
2answers
320 views

Difficulty with auto.arima function results

I am new to R and the ARIMA model and I am attemping to forecast 1440 values into the future using a base of roughly 5000 numbers. It is data extracted roughly every minute from a machine ...
0
votes
2answers
51 views

cumulative distribution function , cdf problem

I cannot understand how step 2 transformed to step 3, anybody help me please ???
2
votes
1answer
146 views

Calculating power function for ANOVA

There are several functions in R to calculate the power of a test, for example, the pwr-functions of the pwr package. My question is how we get this function for ...
0
votes
1answer
40 views

Gradient without function, just testing and training data

I am new to optimization in particular so I think what I am looking for is vocabulary to describe a particular area of problems. In many (all?) optimization algorithms you need to take the gradient of ...
0
votes
0answers
28 views

Empirical Conditional Intensity Function

I'm trying to compute the empirical conditional intensity function in my data. I have two types of events, event Type1 and event Type2, that can occur in a time interval of, say, 1 day (events don't ...
0
votes
1answer
120 views

Function to find the quantile in a vector corresponding to constant $x$ [closed]

Suppose I have constant x=0.1 in the language R and I have a vector vec = rnorm(200). Is ...
7
votes
2answers
217 views

Function of random variables

I am not sure what the right keywords would be for this but I would like to know if it is possible to apply functions to random variables. I think it may make sense in terms of expected value but I ...
1
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1answer
152 views

R - Calculate trendline and extend it for 365 days automatically

I have daily data with logarithmic decreasing trend (around 30-days-data). In excel I'm calculating these data's trendline and with that trendline equation, I'm projecting these values to 365-days ...
2
votes
1answer
39 views

Requirements for evaluation function in evolutionary algorithms

For a publication I'm looking for references for generic requirements of evaluation/fitness functions in evolutionary (more specifically genetic) algorithms. I could come up with some requirements ...
0
votes
1answer
90 views

Can I derive the PDF ( f(C) ) from a spatial function defined as C(x)?

Say I have a random variable (such as concentration) that is defined spatially by some function $C(x)$. I would like to derive a PDF $(f(C))$ from the concentration function $C(x)$ over some domain ...
0
votes
1answer
200 views

Finding the similarity between two functions

I am a first-year grad student in Computer Science, and I need some help with a problem that I think is statistically oriented. I have taken a statistics course, but it was abysmal and I haven't had ...
1
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1answer
118 views

Cumulative function to probability density function

I have some data points for which I would like to show the density using Python, but the package SciPy is not working for Python 3.3. I am looking for a solution to be able to plot some data in the ...
3
votes
1answer
255 views

R: Defining a new continuous distribution function to use with Kolmogorov-Smirnov Test

I wish to run the Kolmogorov-Smirnov test on my data to determine how well it conforms to a specific continuous distribution function I have in mind. If my understanding is correct, the ...
1
vote
1answer
617 views

calculation of correlation time?

I have two time series of a two realizations of a random process, the process fluctuate around an average so i consider that is a ergodic process. I compute the time correlation function, but i need ...
0
votes
1answer
83 views

Can I represent a non-boolean function with a TREE?

I have a question in respect to tree representation of a non-Boolean function. Is there any problem in representing a function from space Boolean->Limited Integer or Limited Integer->Limited ...
1
vote
0answers
80 views

Question related to binomial distribution

Let $X \sim Binomial (n, p)$ with both $n$ and $p$ known. Suppose for some non-increasing function $G:[0,1] \rightarrow [0,1]$, and some fixed $c_0 \in [0,1]$, we have that \begin{align} ...
9
votes
2answers
307 views

How to estimate the accuracy of an integral?

An extremely common situation in computer graphics is that the colour of some pixel is equal to the integral of some real-valued function. Often the function is too complicated to solve analytically, ...
6
votes
1answer
582 views

Proof that if higher moment exists then lower moment also exists

The $r$-th moment of a random variable $X$ is finite if $$ \mathbb E(|X^r|)< \infty $$ I am trying to show that for any positive integer $s<r$, then the $s$-th moment $\mathbb E[|X^s|]$ is ...
2
votes
1answer
152 views

Objective function in linked prediction models

I would like to use R “optimize” function to estimate the model: $\hat{Y_{t}}=a\cdot \hat{Y}_{t-1}+b\cdot X_{t}+c\cdot X_{t-1}$ Important thing is that the predition $\hat{Y_{t}}$ (let’s say ...
0
votes
0answers
148 views

Posterior mean of exponential functions: how to do it with MCMC?

I am struggling with estimation of posterior mean of simple exponential function f(x)=exp(x). Mixing of the chain is quite good and there is no problem with estimation of simple mean, but since ...
-2
votes
3answers
198 views

Find a mapping of two probability mass function to another probability mass function

Lets' $p$ and $q$ are probability mass functions of two discrete random variables. I need examples of functions $F(p,q)$ that $r = F(p,q)$ and $r$ is a probability mass function for some random ...
5
votes
1answer
536 views

In spatial regression, what is a spherical autocorrelation structure?

I have a large gridded dataset for the globe (i.e a spherical, wraparound surface) that I'm applying spatial regression to (using a CAR model). I've been using the default autocorrelation function, ...
9
votes
1answer
350 views

Proving a sequence decreases (supported by plotting a large number of pts)

Many of the questions I've posted on SE in the last month have been in the goal of helping me solve this particular problem. The questions have all been answered, but I still can't come up with a ...
2
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0answers
125 views

Estimating the x-intercept of an arbitrary monotonically increasing function

I have a continuous monotonically increasing function, $f(x)$, whose $x$-intercept, $x^*$, I am trying to estimate. I have a dataset of $(x_i,y_i)$ pairs, with each $y_i=f(x_i)+\varepsilon_i$, where ...
1
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0answers
108 views

What's the difference between $p(x \mid \theta)$ and $p(x; \theta)$? [duplicate]

Possible Duplicate: Meaning of probability notations $P(z;d,w)$ and $P(z|d,w)$ Can you tell me the difference between $p(x \mid \theta)$ and $p(x; \theta)$? I know $p(x \mid \theta)$ is ...
1
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2answers
182 views

Family of functions ranging from zero to one with parameter influencing rate of approach to one

What is a family of functions which goes from 0 to 1 and has one or more parameters that alters the rate at which a value of 1 is approached?