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4
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0answers
24 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). ...
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0answers
23 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
66 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
18 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} ...
1
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0answers
72 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
43 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
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0answers
26 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 ...
4
votes
2answers
81 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 ...
2
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0answers
47 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
18 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
30 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
46 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
votes
1answer
65 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
39 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
58 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
votes
1answer
91 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]). ...
15
votes
2answers
140 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". ...
-2
votes
1answer
50 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
25 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: ...
5
votes
1answer
128 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
107 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
58 views

Vectorize Fisher's Exact Test

I have two data frames/ lists of data, humanSplit and ratSplit, and they are of the form ...
6
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1answer
105 views

Generating Cartesian product of strings in R

Sometimes I need to create character vectors like this one: ...
5
votes
1answer
103 views

Mean of many subsets of a dataframe

I have large dataframe containing many replicates. The replicates are in groups of 3. So the first 3 replicates are in column 1, 2 and 3. The second set 4, 5 and 6... and so on. Now I create a new ...
2
votes
1answer
70 views

Data model code running too slowly

The model takes a long time to run. I have tried to vectorise it as far as I can, but it's still taking about a day to compute. I'm wondering if it's possible to speed it up. Maybe the problem isn't ...
5
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0answers
124 views

Merging overlapping/intersecting string vectors

I am trying to merge overlapping/intersecting sets given as a list of string vectors below in R (my actual data set has thousands of such sets). The overlap/intersection is based on the ...
3
votes
1answer
62 views

Calculating overlap of segments in chromosome data

I wrote an R code that basically performs 2 operations: For each segment in file A, find all segments in file B that lie in that segment. Find the percentage of overlap for each case in previous ...
2
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0answers
42 views

Speed up my backward model selection

I have implemented a quite long program in R and I have noticed that one block, concearning a backward model selection, is too slow and I would like to receive some suggestions in order to speed up ...
4
votes
2answers
65 views

Imperative code in R keeping track of state

A friend of mine has a spreadsheet where she coded a classroom video for various teaching events, which I needed to help her plot. For each recording, she used several video cassettes, and her time ...
3
votes
1answer
323 views

Replace for loop while with apply family function in R

I have trouble with for loop, my code runs very slowly. The thing I want to do is to use function from apply family to make my codes run faster (instead of using ...
2
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0answers
39 views

Merton default model with complex iterative approach

I am using Merton default model with complex iterative approach. I have already prepared my R codes but as I am quite new in R, they seem very inefficient, in sense that they runs almost 7 hours. My ...
0
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0answers
35 views

Create a simulation study using R to compare the accuracy (95% capture rate) and the lengths of the Chi-Squared confidence intervals

The minimum length confidence bounds for a normal population variance for chi-squared distribution is $$ g(a) = a ^\frac{n+1}{2} e^{-\frac a 2} - b^\frac{n+1}{2} e^{-\frac b 2} = 0. $$ Are they ...
2
votes
1answer
100 views

Backwards stepwise regression code in R (using cross-validation as criteria)

I want to write code that does backward stepwise selection using cross-validation as a criterion. I have only started learning R a month ago and I have almost zero programming experience prior to ...
0
votes
2answers
157 views

Optimizing the function in R by replacing for loop

I am trying to create a function that I want to use in my real data. Is there any way to optimize the following function? This is a function I created to filter the data. ...
3
votes
1answer
745 views

best way to apply across an xts object

As xts objects are arrays, getting apply functions to work is a little tricky if you want to preserve the dates. For example, take the ...
2
votes
1answer
48 views

finding names of un-named list elements

I have a naming problem: lists with un-named elements. I wish to get the names of the elements in the list, without going back upstream to where the list was created. An example is ...
3
votes
1answer
124 views

Simplifying loop for Incidence Matrix

I had to work in the Transport Problem and we're asked to try to make the fastest code for big matrices, so we're advised to try to avoid loops. And the only one I've got and I cannot imagine how to ...
2
votes
1answer
110 views

Basic graphical R code draws an ellipse instead of a circle

I wrote some very basic R code. This has at least two problems. It uses a very basic imperative-programming style instead of good R style. It draws the result as an ellipse, not a circle. This ...
2
votes
2answers
170 views

Should I be trying to imitate the control flow in this example R code? [closed]

I have heard that some patterns in R code are really anti-patterns and thus I am trying to imitate superior examples of R code. I am confused about control flow. I have been reviewing some R code ...
2
votes
1answer
66 views

Check column values are in different sets

I have a data frame called data with lots of columns, and Country is one of them. I created a new logical column called ...
1
vote
2answers
167 views

Repeated measures simulator optimisation

I am learning to program in R and to do that and create something useful in the process, I have decided to rewrite this Java applet for repeated measures simulation and to implement some new ...
3
votes
1answer
141 views

Vectorize or otherwise speed up a double for loop

I have this function containing some loops and a double for loop. What it does is set up a matrix first to store results in (the task at hand is comparing genomes) and then with sliding window, ...
1
vote
1answer
79 views

Which components of this r loop are inefficient?

I realize that there is a surfeit of posts on SE/SO about optimizing one's R for() loops. I'm afraid, though, that I don't understand all of the guidance in the answers there, or how to apply their ...
3
votes
1answer
144 views

More elegant filter script in R

I'm very new both to programming and to R so please bear with me :-) I've written the following bit of code, which works perfectly well and runs through a data file with 17446 rows in about 35 ...
1
vote
2answers
104 views

Is this correct R? remove first duplicate dataframe

I have a dataframe with several columns. One of them is an user id column, in this column, I have several ids that can be repeated several times. What I want to do is remove the first id, for ...
4
votes
0answers
235 views

Speed up a monte carlo simulation with nested loop

I would like to know if there is a more efficiency way to speed up below code. It uses a procedure where subsampling is required in the nested loop (which a previous answer helped to make more ...
3
votes
1answer
559 views

Compute intersections of all combinations of vectors in a list of vectors in R

My goal is to compute the intersections of several vectors (sets of identifiers, gene-names to be specific). I start with a list of vectors and run the function below, which loops through 1:n where n ...
2
votes
1answer
184 views

Increase efficiency for an R simulator of the Monty Hall Puzzle

The Monty Hall Problem is a simple puzzle involving probability that even stumps professionals in careers dealing with some heavy-duty math. Here's the basic problem: Suppose you're on a game show, ...
3
votes
2answers
64 views

Speeding up for-loop over a list

I have two lists with ca. 4000 elements where each each element have two columns. These are being fed into a function. Besides the function they are being fed into, is it possible to speed it up ...
3
votes
1answer
148 views

Updating a density distribution

I am running a Markov Chain Monte Carlo algorithm for updating a density distribution. There is a specific section of my code which tries to fill a very large matrix ...