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LazStats: Complete refactoring of FreqUnit.

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git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7691 8e941d3f-bd1b-0410-a28a-d453659cc2b4
This commit is contained in:
wp_xxyyzz
2020-09-23 22:34:12 +00:00
parent 6f16f11ccc
commit e3cd2dea44
9 changed files with 900 additions and 688 deletions
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34
applications/lazstats/source/units/mathunit.pas
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@ -9,9 +9,16 @@ interface
uses
Classes, SysUtils;
const
TWO_PI = 2.0 * PI;
SQRT_PI = 1.7724538509055160;
SQRT2 = sqrt(2.0);
function erf(x: Double): Double;
function erfc(x: Double) : Double;
function NormalDist(x: Double): Double;
function NormalDistDensity(x, AMean, AStdDev: Double): Double;
function Beta(a, b: Double): Extended;
function BetaI(a,b,x: Double): Extended;
@ -27,6 +34,9 @@ function Chi2Density(x: Double; N: Integer): Double;
function CalcC4(n: Integer): Double;
procedure MantisseAndExponent(x: Double; out Mantisse: Double; out Exponent: Integer);
implementation
uses
@ -40,7 +50,6 @@ uses
function erf(x: Double): Double;
const
xup = 6.25;
SQRT_PI = 1.7724538509055160;
c: array[1..18] of Double = (
1.9449071068178803e0, 4.20186582324414e-2, -1.86866103976769e-2,
5.1281061839107e-3, -1.0683107461726e-3, 1.744737872522e-4,
@ -117,8 +126,6 @@ end;
// Cumulative normal distribution
// x = -INF ... INF --> 0 ... 1
function NormalDist(x: Double): Double;
const
SQRT2 = sqrt(2.0);
begin
if x > 0 then
Result := (erf(x / SQRT2) + 1) * 0.5
@ -129,6 +136,11 @@ begin
Result := 0;
end;
function NormalDistDensity(x, AMean, AStdDev: Double): Double;
begin
Result := 1.0 / (sqrt(TWO_PI) * AStdDev) * exp(-0.5 * sqr((x - AMean) / AStdDev));
end;
function Beta(a, b: Double): Extended;
begin
@ -307,5 +319,21 @@ begin
}
end;
procedure MantisseAndExponent(x: Double; out Mantisse: Double; out Exponent: Integer);
var
s, sm, se: String;
p: Integer;
res: Integer;
begin
str(x, s);
p := pos('E', s);
sm := copy(s, 1, p-1);
se := copy(s, p+1, MaxInt);
val(sm, Mantisse, res);
val(se, Exponent, res);
end;
end.