All Questions
636
questions
1
vote
1
answer
57
views
Finding largest root of a function in R
I have a function that is data generated and not a polynomial. For most data, it only has one root, but it can also have two roots, as in in the following plot:
uniroot() tends to fail because the ...
- 1,235
2
votes
1
answer
45
views
What is the problem with my R code for solving and plotting a coupled system of ODE's?
I'm reasonably new to R and have this system of ODEs
\frac{dS}{dT} = -\beta(1-\mu)S(t)\frac{I(t))}{1-D(t))}
\frac{dI}{dT} = -\beta(1-\mu)S(t)\frac{I(t))}{1-D(t))}-\delta I(t))-\phi I(t))
\frac{dR}{dT}=...
1
vote
0
answers
24
views
Ask a coding problem for the equivalence of unconstrained Optimization with L1 Regularization [migrated]
I recently read a statistics paper. It has an unconstrained problem:
$$\min_\theta F(\theta)+\lambda || \theta||_1$$, where $$F(\theta)=L(\theta)+\frac{\rho}{2}|h(W(\theta))|^2+ \alpha h(W(\theta))$$
$...
- 13
1
vote
0
answers
65
views
Why are different variations of wrapping base R functions faster/slower?
I am wrapping a number of R functions in a library (purely for syntax consistency with other systems, not performance or anything else). Something like:
ABS_1 <- function (x) { abs(x) }
ABS_2 <- ...
- 63
0
votes
0
answers
25
views
R script for Bernoulli Equation from reservoir to pipe outlet with friction loss
I was able to write a script that used height as a function for resulting flow out of a pipe. Script attached. However, I am having issues adapting the script to account for friction loss within the ...
0
votes
0
answers
29
views
How to solve error in TukeyHSD (R language) [duplicate]
I always get this error when I want to run the TukeyHSD() for my 2x2 ANOVA.
Here`s the ANOVA I did:
anova_result <- aov(mean_rt ~ congruency * coloring + Error(participant / congruency), data = ...
- 1
1
vote
1
answer
43
views
I am trying to draw a curve and showing it with a single line . Here I face the issue that instead of joining with a single line it shows many
I want to join this curve with single line. But theses points are merging with one another
\lamda =1.8268470
beta= 0.6806978
delta=3.8760680
y<-c(2.01, 6.32, 3.52, 2.15, 5.42, 2.04, 2.77, 2.26, ...
- 11
0
votes
0
answers
50
views
How to find out the function of a negatively skewed curve to solve for Y based on X in R?
I would like to find the function of the following plot so that I may find the Y value for any given X.
This data frame is supposed to look like a negatively skewed distribution curve in order to ...
0
votes
1
answer
66
views
R Lottery function: What's wrong with my work?
I have here a question from an online quiz set by my university (already submitted, so I'm just curious to know what the discrepancy is)
As you can see, there is a set.seed which I have put s into (...
0
votes
0
answers
50
views
One math problem for one row and 3 columns
I am a beginner and am confused; What I have so far
I am supposed to use this data to find:
3e^-x-y^5+2z
How do I combine all these math functions into one to solve?
I'm supposed to calculate that ...
3
votes
1
answer
214
views
How can I compute a dual norm?
Suppose I have a norm ||x||. Is there an R function or method that allows me to calculate the dual norm
||y||_* = \max_{x} x^Ty : ||x|| ≤ 1
?
My initial thought is that this falls under a constrained ...
- 197
0
votes
1
answer
97
views
finding the median of a PDF with r
so i was messing around in r and i was trying to make a function that finds the mean, variance and median (also possibly bounds) of a function. i've been able to get the mean and variance working but ...
- 13
0
votes
0
answers
25
views
Error in match.arg(opt.crit) : 'arg' must be NULL or a character vector
I have an code but it have an error In R, I do not know how to run it.
enter image description here
And here should be run out like this enter image description here
library(forecast)
library(itsmr)
...
- 1
0
votes
0
answers
52
views
How can I remove rows with N/A values after tabulating the database?
This is the code itself. The issue arises when I tabulate the information; the table contains 'Na' values for species that are not found in the sample area. Therefore, I need to find a way to ...
4
votes
2
answers
97
views
R: Plotting a Combinatorial Function
I am working in the R programming language.
I am trying to make a plot from n=0 to n = 1000 for the following function (link: https://www.youtube.com/watch?v=iH2kATv49rc&t=7s):
First, I tried to ...
- 5,705