Linked Questions

2 votes
1 answer
123 views

Significant Difference in prediction when using library and coding from scratch in Multiple Linear Regression [duplicate]

I have been trying to implement multiple linear regression from scratch after implementing it using sklearn. The values predicted using sklearn is very accurate whereas the values predicted by the ...
• 465
1 vote
0 answers
42 views

Various Methods to Calculate Linear Regression [duplicate]

I have just started learning Machine Learning and one of the very first topics that I have encountered in this venture is Simple Linear Regression. From Andrew Ng's course, I have learned to perform ...
• 465
0 votes
0 answers
11 views

What's the point of using gradient descent for linear regression if you can calculate the coefficients directly using the least squares method? [duplicate]

Gradient descent involves significant computational effort, whereas the method of least squares enables direct and accurate calculation. Does gradient descent offer any advantages over least squares ...
33 votes
3 answers
21k views

How could stochastic gradient descent save time compared to standard gradient descent?

Standard Gradient Descent would compute gradient for the entire training dataset. ...
• 1,155
18 votes
4 answers
15k views

Why is gradient descent required?

When we can differentiate the cost function and find parameters by solving equations obtained through partial differentiation with respect to every parameter and find out where the cost function is ...
18 votes
3 answers
10k views

Why not use the "normal equations" to find simple least squares coefficients?

I saw this list here and couldn't believe there were so many ways to solve least squares. The "normal equations" on Wikipedia seemed to be a fairly straight forward way:  {\displaystyle {\begin{...
• 1,170
20 votes
2 answers
21k views

How to choose the right optimization algorithm?

I need to find the minimum of a function. Reading the docs at http://docs.scipy.org/doc/scipy/reference/optimize.html I see that there are several algorithms that do the same thing, i.e. find the ...
• 2,037
8 votes
5 answers
6k views

What is the purpose of a neural network activation function?

What is the purpose of a neural network having a non-linear activation function? Is it correct to say that the non-linear activation function's main purpose is to allow the neural network's decision ...
7 votes
3 answers
8k views

Linear regression for large dataset

If the dataset is too large to be entirely loaded into memory, how can we do linear regression with the dataset?
• 103
3 votes
3 answers
6k views

Why use MSE instead of SSE as cost function in linear regression?

I am studying linear regression and I solved some problems analytically. For that I used the normal and intuitive sum of squared error function. Looking at this function, it makes all sense why it ...
• 131
10 votes
1 answer
6k views

Why is optimisation solved with gradient descent rather than with an analytical solution? [duplicate]

I'm trying to understand why, when trying to minimise an objective function, gradient descent is often used, rather than setting the gradient of the error to zero, and solving it analytically. In ...
• 6,809
4 votes
1 answer
3k views

Single layer neural network as linear regression

I'm really struggling to see the analogy between linear regression and a single layer perceptron. They are supposedly the same thing. I completely understand the concept of the inputs to the neuron ...
• 385
4 votes
1 answer
4k views

Which ML Algorithms are affected by dummy variable trap?

My understanding is that regression models are affected by the dummy variable trap. What about other machine learning algorithms e.g. linear svm, logistic regression? Also, if an algorithm is not ...
1 vote
2 answers
4k views

Full-Rank design matrix from overdetermined linear model

I'm trying to create a full-rank design matrix X for a randomized block design model starting from something like the example from page 3/8 of this paper (Wayback Machine) . It's been suggested that I ...
• 163
7 votes
1 answer
1k views

Difference Between Linear Regression in Machine Learning and Statistical Model

I had the understanding that the major difference between machine learning and statistical model is, the later "assumes" certain type of distribution of data & based on that different model ...
• 6,274

15 30 50 per page