I published a guide to Math HTML on the Internet. Some of the regulars at this forum may find this helpful. Use it with caution! If you cut and paste the HTML code exactly from the page, you shouldn't have any problems, but if you change any character besides the ? (which I used as a dummy character), you may create unintentional HTML code which could have unexpected and unpleasant results!
By the way, I'm still trying to figure out what the script p (Symbol font # 195) character is called and what it's used for, so if anybody knows, or if you have any other constructive criticism for the Math HTML page (which is and will remain a public-access non-profit page), please post your suggestions in this thread.
This message has been edited. Last edited by: silenteuphony,
Posts: 265 | Location: Denver, Colorado, USA | Registered: 06-04-02
I'm sure this contribution of yours will be much appreciated. May I point out one problem I noticed in looking at your chart? In a general form, the HTML code for upper Ascii characters, i.e., characters with Ascii numbers from 128 - 255, is "&#nnn;" where nnn is the Ascii number. Your chart gives many specific examples of these. You appear to have uniformly omitted the semicolon, though. This is obligatory.
I can't find the sign you give for "perpendicular" in my own chart of upper Ascii characters. Do you know its Ascii number?
Can't tell you what à is. I'm thinking electrodynamics?
Posts: 2612 | Location: Upper U.S. | Registered: 06-11-02
I learned a lot of HTML informally, off the Internet as opposed to from an actual text or handbook, and so I'm by no means an expert. Having said that, I figured the purpose of the semicolon is to signify the end of a character code after the ampersand, just as you suggested. However, I also noticed that the browser seems to do fine without it, if it can still "figure out" where the character code ends.
I omitted the semicolon whenever the character code was already enclosed in a <font> </font> pair, since I figured that the browser would assume the character code ended at the </font> code. Of course, it might be safer to leave the semicolon, but why type unnecessary characters? If all people do is cut and paste the code as-is, they should be fine. If they add additional characters inside the <font> </font> pair, then they would definitely need to add the semicolon first.
Of course, one way to know for sure is to check performance on a variety of computers and browsers, which is why I need everyone reading this to help me out. What I really need is counterexamples where the HTML doesn't work right. So if anybody views the page and gets a symbol that doesn't match its description (or any other general weirdness), please let me know.
Meanwhile, we can consider this an Answerpool project with everybody helping to make it perfect. (I haven't told anyone else about my page yet.)
As for the perpendicular symbol, I don't know the ASCII code for it, or if there even is one. I found most of these codes by trial and error, so I may have missed some. I did notice that some of the characters with ASCII codes look different than the corresponding keyboard characters or characters with non-numeric codes (at least on my browser). The percent sign and the plus/minus sign are two examples of this.
P.S. I just checked on a test page, and my system does assume that the character code ends when the <font> </font> pair ends. When I put extra numbers after the code inside the <font> </font> pair, it changed the displayed character, but when I put the extra numbers after the code outside the <font> </font> pair there was no effect on the displayed character.
[This message was edited by silenteuphony on 10-11-02 at 08:08 PM.]
Posts: 265 | Location: Denver, Colorado, USA | Registered: 06-04-02
Sorry about the spacing. The table looks fine as a Word document, but pasting it here messed over the spaces. I'm not going to go to the trouble of creating a table in HTML here. You can read the above if you want to.
SE, all characters in any font have Ascii numbers.
N.B. Characters 130-147, 149-159 and 255 are spaces in this version of symbol font. Do you see any perpendicular sign in there, SE?
Now I see I've corrupted the spacing on SE's and coldfuse's posts, too. Sorry about that. Maybe one of the administrators can repair it. That's what you get for trying to be helpful and messing with HTML in the first place. Beshrew it.
[This message was edited by maiku on 10-12-02 at 06:15 AM.]
[This message was edited by maiku on 10-12-02 at 06:22 AM.]
Posts: 2612 | Location: Upper U.S. | Registered: 06-11-02
Thanks for the list, maiku, you found another one I didn't know about (the "for all" symbol "); I'll have to see if it works on my page. As for the perpendicular sign, I assume you're asking me if I see it because different systems sometimes display characters differently. Unfortunately, no, I don't see it in your list, so the ASCII code is still a mystery. I'm assuming you did see the one in my chart (it looks like an upside-down T). If anybody doesn't see this for the "perpendicular to" sign, please let me know.
In answer to your question, Pin~Jinx, the link that coldfuse provided may help explain what ASCII means, but here's my attempt at an explanation as well. Since a computer uses numbers to represent everything internally, every standard character on a computer has a number code. ASCII was an attempt to standardize the number codes for standard keyboard characters, so computers could speak the same language and understand each other better.
According to the site in coldfuse's link, ASCII was originally designed for use with teletypes, so the first thirty-two characters (numbered 0-31) were obsolete control characters which many systems have replaced with newer characters or commands. Characters 32-127 are fairly standard, and are the same for most systems (most of these are standard keys on a keyboard).
Characters 128-255, called the extended ASCII character set, were added later as people needed more characters (most of these are not standard keys on a keyboard). These are not quite as universal as the basic ASCII character set, but the most common set is included in the site mentioned above.
Both of these characters sets are in the default font for the system. Each font style actually has its own character set, with corresponding ASCII codes. On my Math HTML page, most of the HTML codes include the code
font face="symbol"
which means these characters are not in the default font; they're in the symbol font instead. So all of the number codes listed are actually ASCII codes for the symbol font, as opposed to the standard ASCII codes, which produce totally different characters.
[This message was edited by silenteuphony on 10-12-02 at 02:18 PM.]
Posts: 265 | Location: Denver, Colorado, USA | Registered: 06-04-02
The sign ^ is character 94 in the Symbol font. The sign " is number 34, and I have no idea how it showed up as 148 in my list above. I haven't yet compiled a table of the lower Ascii Symbol font characters, since most of the math symbols are upper Ascii anyway. Character 94 by the way is the circumflex in the standard font, and character 34 is the straight double quote sign.
If you have MS Word, you can find a complete table of the Symbol font by opening a Word document, clicking on the Insert menu, then on Symbol, and then selecting the font Symbol from the scroll down list. The characters are arranged by Ascii number from left to right, top to bottom in 8 rows and 28 columns, so you can count up the Ascii number. The table starts with number 32, however, which is actually the standard space character--as you already pointed out, characters 0-31 are not printable.
One of these days I'm going to prepare a more convenient table with the Ascii numbers written down. Meanwhile, this suggestion might be useful to some of you.
Posts: 2612 | Location: Upper U.S. | Registered: 06-11-02
I just revised the Math HTML page. I got the chart to fit on the screen better, and I rearranged the chart so that equivalent characters (i.e. the same character in default font and symbol font) are on the same row. I also added the " character.
Posts: 265 | Location: Denver, Colorado, USA | Registered: 06-04-02
Pin~Jinx / anarchist
