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Cholesky decomposition: Difference between revisions

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Cholesky decomposition (view source)

Revision as of 15:10, 28 September 2020

83 bytes added ,  3 years ago
Added compatibility for Delphi
m (Enable syntax highlighting for C#)
(Added compatibility for Delphi)
Line 2,450:
 
=={{header|Pascal}}==
<lang pascal>Programprogram CholeskyCholeskyApp;
 
type
D2Array = array of array of double;
 
function cholesky(const A: D2Array): D2Array;
var
i, j, k: integer;
s: double;
begin
setlength(choleskyResult, length(A), length(A));
for i := low(choleskyResult) to high(choleskyResult) do
for j := 0 to i do
begin
s := 0;
for k := 0 to j - 1 do
s := s + choleskyResult[i][k] * choleskyResult[j][k];
if i = j then
cholesky Result[i][j] := sqrt(A[i][i] - s)
else
choleskyResult[i][j] := (A[i][j] - s) / choleskyResult[j][j]; // save one multiplication compared to the original
end;
end;
 
procedure printM(const A: D2Array);
var
i, j: integer;
begin▼
for ji := low(A) to high(A) do▼
begin
for ij := low(A) to high(A) do
write(A[i, j]: 8: 5);▼
▲ begin
writeln;▼
▲ for j := low(A) to high(A) do
▲ write(A[i,j]:8:5);
▲ writeln;
end;▼
end;
end;
 
const
m1: array[0..2, 0..2] of double = ((25, 15, -5), (15, 18, 0), (-5, 0, 11));
m2: array[0..3, 0..3] of double = ((18, 22, 54, 42), (22, 70, 86, 62), (54, 86,▼
(15, 18, 0),
174, 134), (-542, 62, 0134, 11106));
 
▲ m2: array[0..3,0..3] of double = ((18, 22, 54, 42),
(22, 70, 86, 62),
(54, 86, 174, 134),
(42, 62, 134, 106));
var
index, i: integer;
cIn, cOut: D2Array;
 
Line 2,501 ⟶ 2,498:
setlength(cIn, length(m1), length(m1));
for index := low(m1) to high(m1) do
begin
cIn[index] := m1[index];▼
SetLength(cIn[index], length(m1[index]));
for i := 0 to High(m1[Index]) do
▲ cIn[index][i] := m1[index][i];
▲ end;
cOut := cholesky(cIn);
printM(cOut);
 
writeln;
 
setlength(cIn, length(m2), length(m2));
for index := low(m2) to high(m2) do
begin
cIn[index] := m2[index];▼
SetLength(cIn[index], length(m2[Index]));
for i := 0 to High(m2[Index]) do
▲ cIn[index][i] := m2[index][i];
end;
cOut := cholesky(cIn);
printM(cOut);
 
end.</lang>
{{out}}
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