How to write conditional equations with one-sided curly bracket in TeXmacs - texmacs

Here is the photo. How to write conditional equations with one-sided curly bracket in TeXmacs?
I tried inserting Equation and Equations. I didn't manage to insert the curly bracket.
In LaTeX, it's like:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
f(x)=
\begin{cases}
\frac{x^2-x}{x},& \text{if } x\geq 1\\
0, & \text{otherwise}
\end{cases}
\]
\end{document}

I've solved it by myself.
In equation mode you can click on Insert a table in the tool bar, then choose Choice, grid with with one-sided curly bracket will be automatically generated.
Image here: http://i.stack.imgur.com/JE1B8.png

Related

ho to print or export the dates for the values indicated by the arrows

for the code at http://read.pudn.com/downloads160/sourcecode/math/719693/Exploration/Gordon%20Rose%20(617).afl__.htm
how to get the dates where the red arrow i.e higher highs and green arrow i.e low lows to be displayed /listed in interpretation window or to export it to csv
Code is not available. Kindly post here.
By the way, you can add filter = your condition; in your code and then explore using exploration.
https://www.amibroker.com/guide/h_exploration.html
For your help.
Then you can explore your result in csv from file menu.

Azure Pipeline string curly braces

I have an Azure Pipeline variable containing a string into which I wish to insert a JavaScript parameter.
PipelineVariable: 'http://url/${id}'
React function:
myUrl: id =>`#{PipelineVariable}`
Unfortunately it seems the curly braces in Pipeline variable are interpolated so the output of this function is:
http://url/$%7Bid%7D
Any suggestions for how to get round this, presumably by preventing escaping of the braces? I want to call myUrl('12345') and get
http://url/12345
The following does work, but I want to embed the id within the Azure string.
myUrl: id =>`#{PipelineVariable}/${id}`

Inject variable values into Katex/Latex syntax

I am working on a project that uses Katex format to display mathematical formulas.
Now I am facing a bit of a problem here.
For rendering a fraction the katex syntax is
\dfrac{x}{y}
Now if I have a variable x of value 3 and another variable y of value 5.
How would I inject the values into the Katex syntax?
I want to have something like
var x = 3;
var y = 5;
\dfrac{x}{y}
where the x and y in katex syntax will be replaced by the actual values.
Note: I am also using the https://github.com/talyssonoc/react-katex
to render Katex.
I think I'd use macro substitution for this. Try to get your formula expressed as \frac{\x}{\y} by whatever machinery is generating the formula. Then you can substitute either the variable names or the values in place of those macros. Something like this:
katex.render("\\frac{\\x}{\\y}", element, {
macros: {
"\\x": String(x),
"\\y": String(y),
}
});
If you don't have a way to control how the formulas are constructed initially, this merely shifts the problem from substituting values into the formula to substituting commands into it. In that case, you probably want to tokenize the input string into commands \… and other letters. Commands remain as they are, while other letters are subject to variable substitution.
One thing to be careful of is grouping: Input \frac xy renders just fine, but with x=34.5 and y=5.67 substituted in the naive way, the result \frac 34.55.67 (which is what both text and macro substitution will give you) renders as \frac{3}{4}.55.67. So make sure that each macro you have in your formula is enclosed by {…} or add another level of {…} when you do the substitution as in "\\x": "{" + x + "}". Enclosing macros by {…} inside the formula has the benefit that you won't have to worry about a macro eating a subsequent space: \text{\x is 2} is bad but \text{{\x} is 2} is better.
But even with grouping done correctly, this approach is not perfect since not all non-commands are indeed variables. For example with \begin{array}{rlrl}…\end{array} neither the a in array nor the r in rlrl should be considered a variable. Fixing this is really problematic, as it requires a lot of semantic insight.
One way to tackle this dilemma would be letting KaTeX do its rendering and then doing the substitution in the resulting DOM subtree. You should be able to identify variables as <span class="mord …">…</span> (mord stands for math ordinary). This means you depend on the exact representation KaTeX uses for its output, so you should make sure you run a fixed version of KaTeX as these internal things are subject to change without notice. Also be aware of the fact that in some (possibly future) version this might break certain constructs which depend on the width of a given box, although even things as problematic as \underbrace appear to work with this substitution approach at the moment.

Regex for get all html tag without attribute

I need to get all HTML tags without attribute from a string. I tried regex: < *([^/][^ ]*).*?> but it still gets HTML tag and attributes.
Can anyone help me find a regex to get this.
Example:
From <html><head></head><body class="body"></body>,
I want to get <html><head></head><body><a></a></body>.
And a Regex to get only html tag
get to html head head body a a body
Thanks all.
While it's not a good idea in general to try to parse HTML with a regular expression, in this case it works.
Try the following replacement
s/<( *\w+)( [^>/]+)?(/?)>/<$1$3>/g
This matches the opening angle bracket, then captures possible white space and any word characters ([A-Za-z0-9_]) following that. Then if there's a white space followed by any characters that are neither a slash nor a closing angle bracket, it matches that. Then it captures an optional slash and the closing angle bracket.
It replaces this with an opening angle bracket, the captured tag, the captured optional slash, and a closing angle bracket.
This assumes there are no opening or closing angle brackets that are not part of a tag.

Curly braces without variable declaration

Why sometimes C code gets wrapped with curly braces without declaring a variable in them?
e.g. (from FreeRTOS source code, file 'tasks.c'):
portENTER_CRITICAL();
{
xTicks = xTickCount;
}
portEXIT_CRITICAL();
This is just an inner scope. The benefit is that code shows your intent in that case. e.g. This scope is the critical section.
There is no need to use curly braces like this, but it helps readability.
It's a choice of style by the author, I suppose :)

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