June 2018 Update

This commit is contained in:
Ingy döt Net 2018-06-22 20:57:24 +00:00
parent ba8067c3b7
commit 22f33d4004
5278 changed files with 84726 additions and 14379 deletions

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@ -1,11 +1,7 @@
function vdc{T<:Integer}(n::T, b::T)
sum([d*float(b)^-i for (i, d) in enumerate(digits(n, b))])
end
vandercorput(num::Integer, base::Integer) = sum(d * Float64(base) ^ -ex for (ex, d) in enumerate(digits(num, base)))
for i in 2:9
print(" Base ", i)
for j in 0:9
print(@sprintf(" %8.6f", vdc(j, i)))
end
println()
for base in 2:9
@printf("%10s %i:", "Base", base)
for num in 0:9 @printf("%7.3f", vandercorput(num, base)) end
println(" [...]")
end

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@ -0,0 +1,50 @@
MODULE Sequence;
FROM FormatString IMPORT FormatString;
FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
PROCEDURE vc(n,base : INTEGER; VAR num,denom : INTEGER);
VAR p,q : INTEGER;
BEGIN
p := 0;
q := 1;
WHILE n#0 DO
p := p * base + (n MOD base);
q := q * base;
n := n DIV base
END;
num := p;
denom := q;
WHILE p#0 DO
n := p;
p := q MOD p;
q := n
END;
num := num DIV q;
denom := denom DIV q
END vc;
VAR
buf : ARRAY[0..31] OF CHAR;
d,n,i,b : INTEGER;
BEGIN
FOR b:=2 TO 5 DO
FormatString("base %i:", buf, b);
WriteString(buf);
FOR i:=0 TO 9 DO
vc(i,b,n,d);
IF n#0 THEN
FormatString(" %i/%i", buf, n, d);
WriteString(buf)
ELSE
WriteString(" 0")
END
END;
WriteLn
END;
ReadChar
END Sequence.

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@ -6,47 +6,48 @@ if a=='' | a=="," then parse value 0 10 with a b /*Not specified? Then use the
if b=='' | b=="," then b=a /* " " " " " " */
if r=='' | r=="," then r=2 /* " " " " " " */
z= /*a placeholder for a list of numbers. */
do j=a to b /*traipse through the range of integers*/
_=VdC( abs(j), abs(r) ) /*convert the ABSolute value of integer*/
_=substr('-', 2+sign(j) )_ /*if needed, keep the leading - sign.*/
if r>0 then say _ /*if positive base, then just show it. */
else z=z _ /* ··· else append (build) a list. */
end /*j*/
do j=a to b /*traipse through the range of integers*/
_=VdC( abs(j), abs(r) ) /*convert the ABSolute value of integer*/
_=substr('-', 2 + sign(j) )_ /*if needed, keep the leading - sign.*/
if r>0 then say _ /*if positive base, then just show it. */
else z=z _ /* ··· else append (build) a list. */
end /*j*/
if z\=='' then say strip(z) /*if a list is wanted, then display it.*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
base: procedure; parse arg x, toB, inB /*get a number, toBase, and inBase. */
/*┌───────────────────────────────────────────────────────────────────┐
Input to this function: x (is required & must be an integer).
toBase the base to convert X to.
inBase the base X is expressed in.
toBase or inBase can be omitted which causes the default of 10
to be used. Both have a limit of: 2 90.
*/
@abc= 'abcdefghijklmnopqrstuvwxyz' /*the Latin lowercase alphabet chars. */
@abcU=@abc; upper @abcU /*go whole hog and extend characters. */
@@@= 0123456789 || @abc || @abcU /*prefix them with some numeric digits.*/
/*╔══════════════════════════════════════════════════════════════════════════════════╗
Input to this function: x (X is required and it must be an integer).
toBase the base to convert X to (default=10).
inBase the base X is expressed in (default=10).
toBase & inBase have a limit of: 2 90
*/
@abc= 'abcdefghijklmnopqrstuvwxyz' /*the lowercase Latin alphabet letters.*/
@abcU=@abc; upper @abcU /*go whole hog & extend with uppercase.*/
@@@= 0123456789 || @abc || @abcU /*prefix them with the decimal digits. */
@@@= @@@'<>[]{}()?~!@#$%^&*_+-=|\/;:`' /*add some special characters as well, */
/*special characters should be viewable*/
numeric digits 1000 /*what the hey, support biggy numbers.*/
/*──those chars should all be viewable.*/
numeric digits 1000 /*what the hey, support bigun' numbers.*/
maxB=length(@@@) /*maximum base (radix) supported here. */
if toB=='' then toB=10 /*if skipped, then assume default (10)*/
if toB=='' then toB=10 /*if omitted, then assume default (10)*/
if inB=='' then inB=10 /* " " " " " " */
#=0 /* [↓] convert base inB X ──► base 10*/
do j=1 for length(x)
do j=1 for length(x) /*process each "numeral" in the string.*/
_=substr(x, j, 1) /*pick off a "digit" (numeral) from X.*/
v=pos(_, @@@) /*get the value of this "digit"/numeral*/
if v==0|v>inB then call erd x,j,inB /*is it an illegal "digit" (numeral) ? */
#=#*inB + v - 1 /*construct new number, digit by digit.*/
if v==0 | v>inB then call erd /*is it an illegal "digit" (numeral) ? */
#=# * inB + v - 1 /*construct new number, digit by digit.*/
end /*j*/
y= /* [↓] convert base 10 # ──► base toB.*/
do while #>=toB /*deconstruct the new number (#). */
y=substr(@@@, #//toB + 1, 1)y /* construct the output number, ··· */
do while #>=toB /*deconstruct the new number (#). */
y=substr(@@@, # // toB + 1, 1)y /* construct the output number, ··· */
#=# % toB /* ··· and also whittle down #. */
end /*while*/
return substr(@@@, #+1, 1)y
return substr(@@@, # + 1, 1)y /*return a constructed "numeric" string*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
erd: say 'the character ' v " isn't a legal numeral for base " inB'.'; exit 13
/*──────────────────────────────────────────────────────────────────────────────────────*/
VdC: return '.'reverse(base(arg(1), arg(2))) /*convert the #, reverse the #, append.*/

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@ -10,4 +10,6 @@ st_store(k,2,0.5*runiform(2500,1))
st_store(k,3,0.5:+0.5*halton(2500,1))
end
twoway scatter y x, msize(tiny) color(blue) ///
|| scatter z x, msize(tiny) color(green)
|| scatter z x, msize(tiny) color(green) legend(off) xtitle("") ///
title(Distribution: Van der Corput (top) vs pseudorandom) ///
ylabel(, angle(0) format(%3.1f))