1
vote
1answer
31 views

How to perform a monotonic function fitting of data points?

I'm seeking suggestions for general purpose function fitting of a set of data points, where, based on physical intuition, the relationship is expected to be "monotonic", i.e. the function should be ...
0
votes
1answer
47 views

Guess a function that fits empirical data

This is my empirical data: Which function it looks like? I tried to guess (1) a dumped (exponential decaying) sinusoidal, but it does not oscillate after overshoot; (2) a sigmoid, but it oscillate ...
0
votes
0answers
12 views

Measure for functional distance?

Let's say there are input points $X$ and two functions $f$ and $f'$ which have results $Y$ and $Y'$ when applied to $X$. There is no noise in this case. Are there any distance measures that exist to ...
0
votes
1answer
39 views

Regression function - conditional mean

I am trying to understand the statistical fundamentals behind linear regression, and i have never been able to intuitively understand the following; really would appreciate if someone could give an ...
2
votes
1answer
281 views

What is the difference between Curve Fitting and Regression(Machine Learning)?

I know that Machine Learning regression algorithms try to find the function of the data. That is, if we have 1000 data points (x,y), to find a general continuous function that follows the trends of ...
3
votes
0answers
118 views

Can the sigmoid function approximate any function (or relation) where 0<y<1

I'm studying Machine Learning and Artificial Neural Networks. Some basic principles of Machine Learning are linear regression, multivariate linear regression, and nonlinear regression. The last of ...
0
votes
0answers
43 views

Getting formula from known solutions?

Firstly, my first language is not english and I don't really know the technical terms of maths in english, so sorry for my poor expression. I have an equation like $\ y = x * z $. And I know that $\ ...
-3
votes
2answers
121 views

Guess the functional form of a graph

Can you guess the functional form of the following curve y is 0 at x= Infinite ; y is very small ( +ve near to zero) at x=0 Thanks and regards
1
vote
1answer
85 views

Nonlinear regression analysis of a vector

I'm trying to get a nonlinear fit of a vector in Matlab with no success. Let's assume that I have a vector called data: data = [1,30,250,55,22,76] which can be ...
4
votes
0answers
162 views

How to compare the similarity between functions?

I'm designing a web service that finds the regression function of a pattern within an image. I analyzed three images and found the following three regressions: 1) $f(x) = 74.7602 + 0.2005x - ...
0
votes
1answer
89 views

Function description

I have function looks like this: So, the point is after it comes to steady state, it slowly goes down. How can I describe such a behaviour? The datapoints are: ...
2
votes
1answer
238 views

An intuitive explanation for neural networks as function approximators ?

We use normal linear regression for modelling functions on datasets . But Can someone explain how neural networks help in approximating more complex ,especially non-linear functions ? intuitively , ...
0
votes
1answer
99 views

How to convert the constants in a regression equation to constants in a linear equation

Hello dear mathematicians, I'm not entirely sure what to tag this question with since I'm new here but I hope some more experienced user can guide me. Here is my problem: I'm using an internal ...
1
vote
1answer
1k views

Construct / find the simplest function based on data

Let's say I have these 7 natural numbers (all between 0 and 255): 255, 23, 45, 32, 87, 52, 146 How can I find a function F(x) that, once computed, gives me back ...
1
vote
5answers
524 views

Find square root approximation function (tool)

first I have to apologize for any uncorrect naming or categorisation of my question, as I am an electrical engineer rather than a mathematican. I try to find a simple solution for my problem: I have ...
1
vote
1answer
84 views

Measuring how monotonically “staircase-like” a set of values is

A bit of a bizarre question here -- I'm looking for assistance in generating a robust metric to measure how monotonically "step-wise" a series of values is. The set must not start or end at a specific ...
2
votes
2answers
194 views

How to fit an equation to a curve with disturbances

For example, I have the following data: Y = 366 measured values X = 366 measured values t = [ 1 : 366 ], representing the days of the year (index) So at each t (day), we have value of Y and ...