Unicode -- missing arrows - unicode

I'm currently working with arrows in unicode.
According to wikipedia, these five arrows are defined:
↳ ↲ ↱ ↰ ↴
However, three arrows are missing :
leftwards, tip downwards
leftwards, tip upwards
rightwards, tip upwards
How can i find, or, if inexistant, replace them ?

They are provided in the Miscellaneous Symbols and Arrows table:
⬎ ⬏ ⬐ ⬑

Related

Setting button title as unicode character

I have a custom circular button on which I wish to set the lower left pencil unicode as title. I had tried setting the image, but for some reason the image isn't showing up, so I thought of showing the unicode character.
Unicode for lower left pencil is - U+1F589 (Resource - https://www.fileformat.info/info/unicode/char/1f589/index.htm)
Code - customButton.setTitle("\u{1F589}", for: .normal)
Issue - Doesn't work and just shows a question mark on the button.
If I use unicode for lower right pencil, then it works fine.
Code for right pencil - customButton.setTitle("\u{270E}", for: .normal)
Why isn't the code for left pencil working? Am I using the wrong way to set unicode characters for left pencil?
To display a character, it needs to be part of a font, and there is no system font on iOS or Mac that includes this character. In fact, I could only find two fonts on all of fontspace that include it. It is a very rare character.
Since it's been around since 2014 (Unicode 7.0), I doubt it will ever be picked up. It's a kind of a weird character. Neither it nor LOWER RIGHT PENCIL are emoji, so they aren't generally going to display the way you'd want them to, anyway. They're text-only glyphs.
There are a bunch of similar emoji, though:
🖊 U+1F58A LOWER LEFT BALLPOINT PEN
🖋 U+1F58B LOWER LEFT FOUNTAIN PEN
🖌 U+1F58C LOWER LEFT PAINTBRUSH
🖍 U+1F58D LOWER LEFT CRAYON
There is a right facing version of LOWER LEFT FOUNTAIN PEN, U+2711 WHITE NIB (✒️), if you need a matched set. The Swift is "\u{2711}\u{FEOF}".
Your code is fine. You just need to find another character. Lower-right pencil is an old character that has been around for a while judging by its unicode properties (v1.1 versus 7.0). I guess they never thought the need for a lower-left pencil, until now, and it just needs more time before it's (hopefully) more-widely adopted.
https://util.unicode.org/UnicodeJsps/character.jsp?a=270e&B1=Show
Lower-right pencil renders on the official Unicode character property analyzer.
https://util.unicode.org/UnicodeJsps/character.jsp?a=1F589&B1=Show
Lower-left pencil, however, doesn't render.

Unicode value for right arrow with two strokes

I want to use the → character with two // strokes through the arrow but cannot find the unicode value for it anywhere. Does this exist in unicode? If not, is there a way to recreate it?
There are six Unicode characters whose name matches a right arrow with a double stroke, making use of the regular expression: /right.*arrow.*double.*stroke/.
Only two characters appear to be relevant candidates:
⇻ U+21FB RIGHTWARDS ARROW WITH DOUBLE VERTICAL STROKE
⭼ U+2B7C RIGHTWARDS TRIANGLE-HEADED ARROW WITH DOUBLE HORIZONTAL STROKE
(* RIGHTWARDS TRIANGLE-HEADED ARROW WITH DOUBLE VERTICAL STROKE)
Notes:
The official Unicode name of U+2B7C was initially wrong, but a corrected name has been added later as an alias.
U+2B7C appears to be quite uncommon, no suitable font was available in the OS used for the screenshot. Still, it is possible to see what it should look like in the Miscellaneous Symbols and Arrows - Range: 2B00–2BFF PDF document:
I was not successful in finding what you were looking for (negative result). U+0219B is a "Rightwards Arrow with Stroke" and U+021FB "Rightwards Arrow with Double Vertical Stroke". If it exist, it would probably be called "Rightwards Arrow with Double Stroke". https://en.wikipedia.org/wiki/Arrow_(symbol)
The following Unicode sequences should describe your character, but unfortunately fonts are not helping.
→⃫ : \u2192\u20EB
⟶⃫ : \u27F6\u20EB
They are normal and long arrow, with the combining U+20EB: COMBINING LONG DOUBLE SOLIDUS OVERLAY (long double slash overlay). You may find a technical font which can display both in the expected way.
You may get something acceptable also with:
⎯⎯⎯⃫⟶ \u23AF\u23AF\u23AF\u20EB\u27F6 (using arrow extension line)
⎯⎯⃫⟶ \u23AF\u23AF\u20EB\u27F6
Depending on the environment, one of the two seem much better (on my computers).
So: you can express it (semantically) with Unicode, but standards fonts are not helping us. You should experiment with many symbols/mathematical fonts, to get an acceptable solution.
As alternative, you can build such image easily with SVG (and use a SVG as character image).

What do those sideways "L" in BBEdit's gutter area mean?

Please see image below.
Thanks!
Those L-things :-) indicate the end of a foldable range of text (with the downward pointing triangle indicating the start).

Hide/change Emacs fringe bent arrows due to word wrapping?

I would like to change (or hide entirely) the "bent arrow" character that appears in the Emacs fringe (both on the left and right hand side). I'm using Emacs 24 on a Mac, installed via homebrew. I find it to be visually distracting. A smaller character, like a center dot, might work well.
For context, this is an official description of the small bent arrows (from http://www.gnu.org/software/emacs/manual/html_node/emacs/Continuation-Lines.html):
Sometimes, a line of text in the buffer—a logical line—is too long to fit in the window, and Emacs displays it as two or more screen lines. This is called line wrapping or continuation, and the long logical line is called a continued line. On a graphical display, Emacs indicates line wrapping with small bent arrows in the left and right window fringes. On a text terminal, Emacs indicates line wrapping by displaying a ‘\’ character at the right margin.
The Emacs LineWrap Wiki page does not address my question.
The best information I've found so far is contained in this StackOverflow answer:
When word-wrap is set to nil in a text terminal (-nw) Emacs, the backslash character appears on the right margin.
When word-wrap is set to t in a text terminal Emacs, the backslash character is not shown. Setting visual-line-mode also sets word-wrap to true.
This does not apply when Emacs is running as a GUI window: the small bent arrow appears on the right margin regardless of the value of word-wrap.
Is hiding or changing the bent arrows possible? If not, an answer that says, more or less, "I've looked at X and concluded that it is impossible" is ok too.
Update: Although it is not a terrible work-around, changing the fringes is not what I'm looking for: I want to customize the "bent arrow" character or bitmap.
First, some quick context. From Emacs Fringe Bitmaps: "Fringe indicators are tiny icons displayed in the window fringe to indicate truncated or continued lines, buffer boundaries, etc."
You cannot replace the curly arrow with arbitrary text. According to lunaryorn's answer to "Is It Possible To Replace Fringe Bitmaps With Text in Emacs?":
No, it is not. Fringe “bitmaps” are really bitmaps, that is vectors of 0/1 bits, overlayed over the fringe. There is no way to directly render arbitrary unicode characters onto the fringe. [...] What you can do, is to render a unicode character into a 0/1 bitmap yourself.
Like it says, you can change the bitmap. Fringe Bitmaps contains a list of fringe bitmaps; left-curly-arrow and right-curly-arrow are the ones relevant for this question.
Here is what I drew up. Adjust to your liking. Put this in your Emacs init file.
(define-fringe-bitmap 'right-curly-arrow
[#b00000000
#b00000000
#b00000000
#b00000000
#b01110000
#b00010000
#b00010000
#b00000000])
(define-fringe-bitmap 'left-curly-arrow
[#b00000000
#b00001000
#b00001000
#b00001110
#b00000000
#b00000000
#b00000000
#b00000000])
More documentation is available at Customizing Bitmaps, including set-fringe-bitmap-face which "sets the face for the fringe. If face is nil, it selects the fringe face. The bitmap's face controls the color to draw it in".

Matlab: Adding symbols to figure

Below is the user interface I have created to simulate LDPC coding and decoding
The code sequence is decoded iteratively by passing values between the left and right nodes through the connections.
The first thing it would be good to add in order to improve visualization is to add arrows to the connections in the direction of passing values. The alternative is to draw a bigger arrow at the top of the connection showing the direction.
Another thing I would like to do is displaying the current mathematical operation below the connection (in this example c * H'). What I don't know how to do is displaying special characters and mathematical symbols and other kinds of text such as subscript and superscript in the figure (for example sum sign and subscript "T" instead of sign ="'" to indicate transposed matrix).
I would be very thankful if anyone could point to any useful resources for the questions above or show the solution.
Thank you.
To add arrows, you can either use the built-in QUIVER, or, for more options, ARROW from the file exchange. Both of these have to be plotted into axes, so if you want a big arrow on the top, you have to create an additional set of axes above the main axes.
As far as I know, you cannot use TeX or LaTeX symbols in text uicontrols. However, you can use them in axes labels. Thus, I suggest that you add an XLabel to the axes, for example
xlabel('\sigma c*H_T')
or (note the $-signs required for LaTeX)
xlabel('$\sum c*H_T$','interpreter','latex')
EDIT
I hadn't mentioned the use of text (as suggested by #gnovice and #YYC) because I thought it wasn't possible to place text outside of the axes. It turns out that I was wrong. text(0.5,-0.2,'\Sigma etc.') should work fine as well. I guess the only advantage of using 'xlabel' would be that you can easily add and position the axes label during GUI creation.
In regards to the 1st question, annotation (http://www.mathworks.com/access/helpdesk/help/techdoc/ref/annotation.html) might be an alternative solution.
In regards to the 2nd question, try text property in Matlab Help.
Search "Character Sequence" for the special characters; search "Specifying Subscript and Superscript Characters" for the subscript and superscript.
For drawing the arrow, I would go Jonas' suggestion arrow.m by Erik Johnson on the MathWorks File Exchange. It's the easiest way I've found to create arrows in figures.
For creating text with symbols, you can use the function TEXT. It lets you place text at a given point in an axes, and you can use the 'tex' (default) or 'latex' options for the 'Interpreter' property to get access to different symbols. For example, this places the text you want at the point (0,0) using 'latex' as the interpreter:
hText = text(0,0,'$\sum c*H_T$','Interpreter','latex');
The variable hText is a handle to the text object created, which you can then use with the SET command to change the properties of the object (string, position, etc.).