Is it Aarhus or Århus?

Aarhus. Denmark's 1948 spelling reform replaced aa with å, and the city wrote Århus for decades, but it went back to Aarhus as its official spelling in 2011. Both names refer to the same place, and aa is still the usual stand-in for å in Danish and Norwegian whenever a system only accepts ASCII.

Why does R read å as Ã¥ from my CSV?

On Windows, R before version 4.2 read files in the system code page, usually Windows-1252, so the UTF-8 bytes of å came in as Ã and ¥. Name the encoding when reading: `read.csv(path, fileEncoding = "UTF-8")`. R 4.2 and later use UTF-8 on Windows too, so upgrading removes the problem for new scripts.

Why do I get σ from Alt+229?

The short code comes from the DOS table, where 229 is the Greek small sigma. The Windows number for å only works with the leading zero, so type Alt+0229, and Alt+0197 for the capital Å.

ASCII 229

Lowercase a with ringGreek small sigma

ASCII 229 is å on Windows and σ in old DOS.

å (Small A with Ring) is byte 229 in Windows-1252, Unicode U+00E5. It's a full letter in Swedish, Norwegian and Danish, as in på and år. Danish sorting has a twist. The old spelling aa counts as the same letter as å, and both go at the very end of the alphabet, so with a Danish collation Aalborg sorts after Odense and even after Zealand. JavaScript's Intl.Collator('da') and databases set to a Danish locale do exactly that, while a plain byte sort puts Aalborg first. Old DOS had å at 134. In UTF-8 it's C3 A5, which misreads as Ã¥. The HTML entity is å.

σ (Small Sigma) is byte 229 in code page 437, the original IBM PC character set, and maps to Unicode U+03C3. Statistics uses it for the standard deviation of a whole population, and the symbol decides which formula you need. σ divides by n, the sample standard deviation s divides by n − 1, and Excel splits them into STDEV.P for σ and STDEV.S for s. On small samples the two give noticeably different results, so pick the one that matches the symbol in your source. Code page 850 put Õ on this byte. In UTF-8, σ is CF 83, and the HTML entity is σ.

Latin LetterGreek Letter

Technical Details

Code Example

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#include <stdio.h>

int main(void) {
    /* On Windows (code page 1252) byte 229 is å.
       Modern terminals expect UTF-8, so print the code point, not the byte. */
    printf("\u00E5\n");   /* UTF-8: C3 A5 */

    unsigned char b = 229;         /* the raw Windows-1252 byte */
    printf("%d 0x%02X\n", b, b);    /* 229 0xE5 */
    return 0;
}

Code Example

</>

#include <stdio.h>

int main(void) {
    /* Byte 229 is σ only on a console using code page 437
       (chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the
       lone byte 0xE5 is invalid and prints as garbage, often �. */
    putchar(229);

    /* char is signed on x86, so a plain char holding 0xE5 is -27.
       Use unsigned char when you compare or index by byte value. */
    char c = (char)229;
    unsigned char u = 229;
    printf("\n%d %d\n", c, u);   /* -27 229 */

    /* Portable: print the Unicode character as UTF-8 instead. */
    printf("\u03C3\n");          /* CF 83 */
    return 0;
}

How to Type It

Windows: Hold Alt and type 0229 on the numeric keypad, with Num Lock on. The leading zero picks the Windows code page. Alt+134, without the zero, types it too. No numeric keypad? In Word, type 00E5 and press Alt+X.
Mac: Press Option+A.
Linux: In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type e5, then Space. With a Compose key set up, press Compose, o, a.
Phone: Long-press a and pick å.

How to Type It

Windows: Hold Alt and type 229 on the numeric keypad, with no leading zero. US PCs insert σ, but PCs set to code page 850, common in Western Europe, insert Õ. No numeric keypad? In Word, type 03C3 and press Alt+X.
Mac: Press Control+Command+Space to open the Character Viewer, then search for "greek small letter sigma".
Linux: In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type 3c3, then Space.
Phone: Add the Greek keyboard in your phone's keyboard settings and type σ there, or tap the character at the top of this page to copy it.

Frequently Asked Questions

Aarhus. Denmark's 1948 spelling reform replaced aa with å, and the city wrote Århus for decades, but it went back to Aarhus as its official spelling in 2011. Both names refer to the same place, and aa is still the usual stand-in for å in Danish and Norwegian whenever a system only accepts ASCII.
On Windows, R before version 4.2 read files in the system code page, usually Windows-1252, so the UTF-8 bytes of å came in as Ã and ¥. Name the encoding when reading: `read.csv(path, fileEncoding = "UTF-8")`. R 4.2 and later use UTF-8 on Windows too, so upgrading removes the problem for new scripts.
The short code comes from the DOS table, where 229 is the Greek small sigma. The Windows number for å only works with the leading zero, so type Alt+0229, and Alt+0197 for the capital Å.

Frequently Asked Questions

The short code comes from the DOS table, where 229 is the Greek small sigma. The Windows number for å only works with the leading zero, so type Alt+0229, and Alt+0197 for the capital Å.

ASCII 229

Lowercase a with ringGreek small sigma

ASCII 229 is å on Windows and σ in old DOS.

Latin Letter

Greek Letter

#include <stdio.h>

int main(void) {

/* On Windows (code page 1252) byte 229 is å.

Modern terminals expect UTF-8, so print the code point, not the byte. */

printf("\u00E5\n"); /* UTF-8: C3 A5 */

unsigned char b = 229; /* the raw Windows-1252 byte */

printf("%d 0x%02X\n", b, b); /* 229 0xE5 */

return 0;

}

#include <stdio.h>

int main(void) {

/* Byte 229 is σ only on a console using code page 437

(chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the

lone byte 0xE5 is invalid and prints as garbage, often �. */

putchar(229);

/* char is signed on x86, so a plain char holding 0xE5 is -27.

Use unsigned char when you compare or index by byte value. */

char c = (char)229;

unsigned char u = 229;

printf("\n%d %d\n", c, u); /* -27 229 */

/* Portable: print the Unicode character as UTF-8 instead. */

printf("\u03C3\n"); /* CF 83 */

return 0;

}