Use \nabla to print an upside-down triangle to represent gradient descent. The effect is like this:
Monthly Archives: April 2015
How does gradient vanish in Multi-Layer Neural Network?
Background This post reviews how we update weights using the back propagation approach in a neural network. The goal of the review is to illustrate a notorious phenomenon in training MLNN, called “gradient vanish”. Start Let’s suppose that we have a very simple NN structure, with only one unit in each hidden layer, input layer …
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How to view all columns of a data.frame in R
If you want to view a large data.frame with a large number of columns in R, you will only see first several columns in the UI. After reading this post, I found that if using utils::View(your_data_frame) , you can view all the columns in a new window. Reference: http://stackoverflow.com/questions/19341853/r-view-does-not-display-all-columns-of-data-frame
Logical deduction in NP-completeness proof
Maybe it sounds simple to computer scientists, I just want to backup some logical deduction of myself in NP-completeness proofs in case I will deal with such proofs in the future. In NP-completeness proof, we always want to find a polynomial-time reduction (transformation) from problem A to problem B, denoted as: We say that there …
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2-SAT is in P
Guitar Chord Music Theory
It’s a bit shame that I just start to learn music theory of guitar chords after FIVE years since I picked up guitar. In this post I will share how I have learned guitar chords from beginning. 1. know mappings from alphabets to do-rei-mi-fa-so-la-si C is DO, D is REI, E is MI, so …
A general way to add backslash on symbols in latex
You know, in latex you can type \neq to make an inequation symbol: `$latex \neq$` Of course, you don’t want to remember how to type in latex all symbols with backslash on them. So here is a general way to add backslash on any symbol in latex: add `\not` in front of a normal …
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Proof that BFS finds shortest distance
Intuitively, Breadth-First Search (BFS) can find shortest distances from a source $latex s&s=4$ to any other reachable vertex. However, proving this intuition needs a bit hard work. After some searches, I found that there are two ideas to prove it. The two ideas both use induction to prove it. Both ideas require a bit long proof. …
How to migrate WordPress from one host from another?
WordPress really SUCK! It doesn´t provide a viable, simple and easy solution for export/import of your whole site. Here I am sharing how I managed to migrate my WordPress site from an old host to a new one. make sure Apache2, PHP, MySQL, and PHP MySQL extension work in perfect on your new host. Here …
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How to make contents wider in WordPress Theme?
It again proved how silly WordPress is: I can’t find any theme with wide content area. Why do we have to waste almost a third of page area in EVERY WordPress theme? I read many articles about how to make custom CSS to widen the content column but no magic happened. So I decided to modify …
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