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Verify distribution uniformity/Naive: Difference between revisions
Verify distribution uniformity/Naive (view source)
Revision as of 14:14, 20 September 2015
, 8 years agoAdd Forth
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Line 568:
"Random enough"</pre>
=={{header|Forth}}==
requires Forth200x locals
<lang forth>: .bounds ( u1 u2 -- ) ." lower bound = " . ." upper bound = " 1- . cr ;
: init-bins ( n -- addr )
cells dup allocate throw tuck swap erase ;
: expected ( u1 cnt -- u2 ) over 2/ + swap / ;
: calc-limits ( n cnt pct -- low high )
>r expected r> over 100 */ 2dup + 1+ >r - r> ;
: make-histogram ( bins xt cnt -- )
0 ?do 2dup execute 1- cells + 1 swap +! loop 2drop ;
: valid-bin? ( addr n low high -- f )
2>r cells + @ dup . 2r> within ;
: check-distribution {: xt cnt n pct -- f :}
\ assumes xt generates numbers from 1 to n
n init-bins {: bins :}
n cnt pct calc-limits {: low high :}
high low .bounds
bins xt cnt make-histogram
true \ result flag
n 0 ?do
i 1+ . ." : " bins i low high valid-bin?
dup 0= if ." not " then ." ok" cr
and
loop
bins free throw ;</lang>
{{output}}
<pre>cr ' d7 1000000 7 1 check-distribution .
lower bound = 141429 upper bound = 144285
1 : 143241 ok
2 : 142397 ok
3 : 143522 ok
4 : 142909 ok
5 : 142001 ok
6 : 142844 ok
7 : 143086 ok
-1
cr ' d7 10000 7 1 check-distribution .
lower bound = 1415 upper bound = 1443
1 : 1431 ok
2 : 1426 ok
3 : 1413 not ok
4 : 1427 ok
5 : 1437 ok
6 : 1450 not ok
7 : 1416 ok
0</pre>
=={{header|Fortran}}==
{{works with|Fortran|95 and later}}
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