Uncategorized - Read For Learn

How do I learn WebGL the fast way?

http://learningwebgl.com/blog/?p=11 (dead link as of Nov 2018, backup: https://web.archive.org/web/20180615095219/http://learningwebgl.com/blog/?p=11) Yes, I could recommend Light House 3D: http://www.lighthouse3d.com/tutorials/glsl-core-tutorial/ It’s not that complex, just focus on the code written on Learning webGL. I wouldn’t recommend working with some other library/engine at the start. Learn basics and later use libraries to speed up your coding. Learning webGL is great place to … Read more

What is a callback URL in relation to an API?

I’ve been scouring the net, and can’t seem to wrap my head around the idea of a callback URL. In my case I have a few callback URLs that I have to define myself. A popular one is a “default callback URL”. What is this exactly? Can you give an example in plain english?

Floating div positioning

. I need a floating rectangle (100% width, 100px height) to appear exactly 20px above the bottom of a page. How can I do that? The code below shows the rectangle at the bottom of the browser window not the page – so if the page is taller than what can fit in the screen, … Read more

XQuery data and text() function

text() is used to match something. For example if we have this structure: Doing //b/text() will return the text node ‘hello ‘ just like //b/element() will return the element c. data($arg) is a function that returns the atomic value of a node, for example data(//b) will return ‘hello world’. If you use the data($arg) function … Read more

What is the difference between == and equals() in Java?

In general, the answer to your question is “yes”, but… .equals(…) will only compare what it is written to compare, no more, no less. If a class does not override the equals method, then it defaults to the equals(Object o) method of the closest parent class that has overridden this method. If no parent classes have provided an … Read more

expected assignment or function call: no-unused-expressions ReactJS

This happens because you put bracket of return on the next line. That might be a common mistake if you write js without semicolons and use a style where you put opened braces on the next line. Interpreter thinks that you return undefined and doesn’t check your next line. That’s the return operator thing. Put your opened bracket on … Read more

pagebreak in markdown while creating pdf

I encountered the same and solve it by inserting \pagebreak It’s actually a LaTeX command, rather than a Markdown one.

How to write trycatch in R

Well then: welcome to the R world 😉 Here you go Setting up the code Applying the code Investigating the output Additional remarks tryCatch tryCatch returns the value associated to executing expr unless there’s an error or a warning. In this case, specific return values (see return(NA) above) can be specified by supplying a respective handler function (see arguments error and warning in ?tryCatch). These … Read more

How to append text to a text file in C++?

You need to specify the append open mode like

How to convert .crt to .pem [duplicate]

You can do this conversion with the OpenSSL library. Windows binaries can be found here. Once you have the library installed, the command you need to issue is:

+ More