R is a free, open source programming language and software environment for statistical computing and graphics.

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14 views

Could anyone help me check my gibbs sampling code in R? [closed]

I am now trying to write a Gibbs Sampling code based on the posteriors from a paper "Bayesian Regularization via Graph Laplacian", writer: Fei Liu, et. When I run the code, it always show the error: ...
2
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1answer
38 views

Fill missing values based on group

I am trying to fill values based on group, in my case id. I would like to fill the missing values according to the available ...
0
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1answer
29 views

3D plot from lm model with a nonlinear parameter

I am trying to plot a 3Dplot of a linear regression with two variables. My linear model: ls = lm(mpg ~ disp + qsec, data = mtcars) The minimum and maximum ...
4
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1answer
45 views

Long format data - fill episode based on conditional previous episode

The data are organised as long format data. 4 individuals are observed during 4 or 5 days (BCSID is the name of the unique key). Basically, the data describe ...
1
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1answer
28 views

Programmatic text substitution across rows and columns in R

I'm replaced character strings with numeric codes in R. I find myself doing a lot of copying and pasting, so there's probably a better solution with apply, ...
2
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2answers
59 views

Calculate number of co-occurrences for two vectors

I would like to understand how to get rid of all the loops I am using in this code. I have a dataframe of 20 rows. I am simply counting the number of occurrences that the variables ...
3
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1answer
36 views

Implementation of KNN in R

I have implemented the K-Nearest Neighbor algorithm with Euclidean distance in R. It works fine but takes tremendously huge time than the library function (get.knn). Please point out the possibility ...
3
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1answer
39 views

Identify changes between two data.frames, explain deltas for x columns

I wrote the following snippet to deal with a situation in which I have two datasets (usually the current version versus a previous one) and I need to identify what changes have occured: usually ...
4
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1answer
51 views

Plotting a vector field in R + ggplot

I've written a small program that draws a vector field in R using ggplot for a given differential equation. There is a topic on the subject here however, the proposed solutions either don't provide ...
3
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1answer
36 views

Value matching in R

I have three data frames A, B and C: ...
2
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1answer
34 views

Scaling up the intelligent concatenation of 2 columns in R

I've got a huge dataset in R which contains (among other things) 2 columns indicating "Term Code", which are "Term Code" and "Term Code1". "Term Code" is the mostly-correct column, which usually ...
1
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0answers
49 views

Numerical maximization procedure normal distribution

Firstly, I programmed this gaussian density as an R function which takes the parameters mean and variance (mean=4,sd=1) and ...
0
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0answers
15 views

Numerical maximization procedure normal distribution functions

I generate a sample of size 1000 consisting of realizations of independent N(4, 1) distributed random variables: n <- 1000 x <- rnorm(n, mean = 4, sd = 1) ...
4
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0answers
31 views

Pivot-friendly binning of arbitrary vector

I frequently get a situation in which I want a pretty binned column from a vector of values, so that I divide the vector in approximately even ranges and choose 'sensible' values so that it looks ...
1
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0answers
43 views

Algorithm for correcting missing values

I have problem with setting missing values in data frame. In the first 3 columns there are ID of product, ID of store, and number of week. There are also 28 columns from 4 to 31 corresponding to last ...
3
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1answer
79 views

Nonlinear Scaling Normalization

I have a procedure for normalizing variables, the details of which can be viewed in this white paper. I would like to be able to make the routine scalable to handle any number of variables. Below is ...
4
votes
2answers
70 views

Reducing memory usage for FizzBuzz in R

I've been trying all night to get my fizzbuzz to use below 20 MB of RAM but I can't seem to get it much smaller than this. ...
3
votes
1answer
44 views

Fast canonical indexing of elements in array

Given two arrays of elements: aaabbccdefaa zzzccddafgzz I want to check whether these two arrays are equivalent up to a relabeling. My strategy is to map them into a canonical form and ...
1
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0answers
76 views

Time-course of drug amounts in the different compartments of a pharmacokinetic system

I am looking for a way to speed up applying my function to every individual in the data frame. Currently I am using the ddply but it is very slow for big data sets. ...
2
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0answers
110 views

Genetic algorithm for the minimum of the Schaffer function

I have to implement a genetic algorithm in R to optimize the minimum of the Schaffer function. Below I describe each step and I need to create one big function and another loop for 100 iterations (and ...
0
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0answers
70 views

Stochastic gradient descent in R

Please, review my code, which counts global minimum with method stochastic gradient descent for schaffer function ...
5
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1answer
267 views

Simulated annealing in R

I am new in R and I have to implement simulated annealing for schaffer function and I did it. However I am not sure about the correctness of the code. ...
1
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0answers
94 views

Naive Grouping for Factorization

UPDATE: I have posted this question on math.se along with the identification of a new relationship to lattice points on hyperbola. I have a naive grouping method for factorization. I am curious as ...
3
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1answer
118 views

Trial Multiplication for Factorization

I am trying a trial multiplication for factorization. This is a general example, but each sequence can be specified to pairs of sequences \${p,q}\$ for a given \$n\$. For example, if \$n\$ ended in 3, ...
3
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0answers
42 views

Computing pairwise distance covariances for a symmetric matrix

I wrote a non-vectorized, non-parallel wrapper function for computing the pairwise distance covariances (Wikipedia) (original paper) in a data frame: ...
6
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2answers
73 views

2D lattice random walk plots in functional style

To practice writing code in the functional programming style, I wrote a program to plot two-dimensional lattice random walks. I'd appreciate any feedback about how to improve its "functionaliness". ...
4
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0answers
113 views

Crawling and parsing meteorological data from the web into R

I am interested in collecting directly into R data published by the Mexican Met-office. The data pieces are spread through several URLs, but one can start here. There I can get the names and ...
1
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0answers
80 views

Extract and rename specific columns of a CSV data file

I have a CSV data file with 3,896 columns (variables), and I am attempting to extract a particular subset of columns for use in a data analysis project. To avoid the burden of having to constantly ...
6
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1answer
63 views

Lookup GINI by year and country

This takes a dataframe as an argument, looks at all pairs of two columns in that data frame (country and year) and returns a column value of that pair in another data frame (the gini number). ...
4
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1answer
214 views

Sublime Text 2 R Build System (source file, send selection to interactive session)

The following is the description of the R build system I am using (very happy) with Sublime Text 2 on linux (Crunchbang). With it, I am able to: to source the current file.R to an interactive R ...
2
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0answers
111 views

Smoothing matrix for visual representation

I recently started playing around with R and am currently trying to plot GPS data points onto a perspective plot. I have a script that works and I get my desired results out of it and it works ok for ...
3
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0answers
44 views

Volatility updating with Heston-Nandi model

I'm trying to program a volatility updating rule using iteration. I start with the well-known Heston-Nandi model where the returns dynamics are: $$ \left\{ \begin{array}{rcl} R_{t+1} ...
2
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1answer
123 views

Quick estimation for empirical permutation and correlation test in R

I have two matrices (a, b), each including 3 genes and 6 observations. I have estimated the Spearman correlation for gene pairs (rcorr.observed). Then I want to do an empirical permutation (1000 ...
3
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2answers
74 views

Python path-breaking script for use in R

R does not support line continuation as Python, and it's disturbing to have long file paths like /media/user/data/something-not-very-important-but-super-long/some-curious-secret-file.pdf and ...
4
votes
1answer
67 views

Creating a special Toeplitz matrix in R

I'd like to know if there is a standard way of creating a matrix like the one shown below using the R programming language. $$ \begin{bmatrix} 1 & \rho & \rho^2 & \cdots ...
5
votes
2answers
113 views

Concisely adding values in a loop to a column

In my data frame I assign values to the column Register by checking another column (Source) for specific values. Based on those values, the output in Register changes. I am relatively new to R, but I ...
3
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1answer
58 views

Simulation of animal skins

This is a simulation of animal skins, like a cellular automat. I'd like it improved. ...
1
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0answers
29 views

Comparison of two regression types on the same set of models

I wrote a relatively simple R script to run a bunch of regressions. To be precise, it is a hurdle negative binomial regression (fancy stuff for count data). To print it out easily to ...
3
votes
1answer
36 views

Merging predicted values into measured values

I created the following function below to merge the real values with the predicted values (when real are absent) in a new column in data.frame. The function ...
1
vote
3answers
202 views

An R function for checking whether a variable is binary or continuous

This function takes a numeric vector and returns "con" if it's continous and "bin" if it's binary. It does not take the multinomial case into account, i.e. if a variable y has three possible values ...
4
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1answer
81 views

Speeding up nested for-loop analysis code

I have two matrices, the first one is mat 2000*500, the second one is 6000*500 ...
1
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1answer
54 views

Frequency form to case form - unexpected values in table

I'm taking count data on voting preferences by race and entering it into a table in frequency form, then expanding out to case form and using CrossTable to look at ...
3
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0answers
68 views

Finding the Cox regression coefficients in a mixed model for microarray data

I have written a code for a project which aims at finding the Cox regression coefficients in a mixed model for microarray data. The study was carried out on the Affymetrix Hgu133a platform. In the ...
5
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1answer
105 views

Vector comparison inside for-loop

The following code finds no-rain periods in a time series that were preceded by rain over a threshold (e.g. 10mm in 2 days [k=48]). ...
19
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2answers
194 views

Plot daily time spent on codereview.stackexchange.com

This draws an xyplot from csv data obtained from RescueTime API for activity time for "http://codereview.stackexchange.com". ...
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1answer
55 views

How I can generalise this code

I have this code and I want to generalize it and make it efficient. Each time I generate a number of random variables and I put it in the m equation to generate m. Can I get any help to simplify this ...
2
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0answers
30 views

Computing values with several large numeric vectors

I have several large numeric vectors (close to 1e6 entries each) and I need to make some computations with their values: ...
7
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1answer
284 views

Using Reddit API in R

I'm scraping some comments from Reddit using Reddit JSON API and R. Since the data does not have a flat structure, extracting it is a little tricky, but I've found a way. To give you a flavour of ...
4
votes
2answers
174 views

Calculation of mortgage repayments

I've just started learning R, but I feel that I'm using it only as a normal procedural language without taking advantage of some built-in functions and data structures. I wrote a function that ...
4
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0answers
79 views

Vectorize Fisher's Exact Test

I have two data frames/ lists of data, humanSplit and ratSplit, and they are of the form ...