Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Commit d2f124f

Browse files
Add 3 new routines to Maths category
The routines are: * PowN * PowNZN * PowNZZ Add compile result for all three for Delphi XE, 11 & 12. Add test info showing advanced / unit tests Also updated Pow function entry to cross reference these new routines. Add test info for PowNxx functions
1 parent b5026e9 commit d2f124f

File tree

4 files changed

+95
-0
lines changed

4 files changed

+95
-0
lines changed

‎collection/633.dat‎

Lines changed: 21 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,21 @@
1+
function PowN(const X: Extended; const N: Integer): Extended;
2+
var
3+
I: Integer;
4+
begin
5+
if N = 0 then
6+
// IEEE: pown(x, 0) is 1, even when X is zero
7+
Exit(1.0);
8+
if Math.SameValue(1.0, X) then
9+
Exit(1.0);
10+
if Math.IsZero(X) then
11+
begin
12+
if N < 0 then
13+
raise SysUtils.EDivByZero.Create('PowN: Negative exponent for X = 0');
14+
Exit(0.0);
15+
end;
16+
Result := 1.0;
17+
for I := 1 to System.Abs(N) do
18+
Result := Result * X;
19+
if N < 0 then
20+
Result := 1 / Result;
21+
end;

‎collection/634.dat‎

Lines changed: 12 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,12 @@
1+
function PowNZN(const X: Integer; const N: Cardinal): Int64;
2+
var
3+
I: Integer;
4+
begin
5+
if (X = 0) and (N > 0) then
6+
Exit(0);
7+
if X = 1 then
8+
Exit(1);
9+
Result := 1;
10+
for I := 1 to N do
11+
Result := Result * X;
12+
end;

‎collection/635.dat‎

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
function PowNZZ(const X: Integer; const N: Integer): Extended;
2+
var
3+
I: Integer;
4+
ResultInt: Int64;
5+
begin
6+
if N = 0 then
7+
Exit(1.0);
8+
if X = 1 then
9+
Exit(1.0);
10+
if X = 0 then
11+
begin
12+
if N < 0 then
13+
raise SysUtils.EDivByZero.Create('PowNZZ: Negative exponent for X = 0');
14+
Exit(0.0);
15+
end;
16+
ResultInt := 1;
17+
for I := 1 to System.Abs(N) do
18+
ResultInt := ResultInt * X;
19+
if N > 0 then
20+
Result := ResultInt
21+
else // N < 0
22+
Result := 1 / ResultInt;
23+
end;

‎collection/maths.ini‎

Lines changed: 39 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1178,6 +1178,7 @@ FPC=Y
11781178

11791179
[Pow]
11801180
DescEx="<p>Raises integer value <var>Base</var> to non-negative integer power <var>Exponent</var> and returns the result.</p>"
1181+
SeeAlso=PowN,PowNZN,PowNZZ
11811182
Snip=561.dat
11821183
Delphi2=N
11831184
Delphi3=N
@@ -1197,6 +1198,44 @@ DelphiXE4=Y
11971198
Delphi10S=Y
11981199
FPC=Y
11991200

1201+
[PowN]
1202+
DescEx="<p>IEEE compliant function that raises real number <var>X</var> to the power <var>N</var>.</p>"
1203+
Extra="<p>See IEEE standard 754-2008 for Floating-Point Arithmetic, page 44.</p>"
1204+
Units=SysUtils,Math
1205+
SeeAlso=Pow,PowNZN,PowNZZ
1206+
TestInfo=advanced
1207+
AdvancedTest.Level=unit-tests
1208+
AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
1209+
Snip=633.dat
1210+
DelphiXE=Y
1211+
Delphi11A=Y
1212+
Delphi12A=Y
1213+
1214+
[PowNZN]
1215+
DescEx="<p>Raises integer <var>X</var> to non-negative integer power <var>N</var>.</p>"
1216+
Extra="<p>Returns an <var>integer</var> value because the power <var>N</var> is non-negative which guarantees that the result is integral.</p><p>Based on IEEE standard 754-2008 for Floating-Point Arithmetic, page 44, but which restricts <var>X</var> to an integer and <var>N</var> to a non-negative integer.</p>"
1217+
SeeAlso=Pow,PowN,PowNZZ
1218+
TestInfo=advanced
1219+
AdvancedTest.Level=unit-tests
1220+
AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
1221+
Snip=634.dat
1222+
DelphiXE=Y
1223+
Delphi11A=Y
1224+
Delphi12A=Y
1225+
1226+
[PowNZZ]
1227+
DescEx="<p>Raises integer <var>X</var> to integer power <var>N</var>.</p>"
1228+
Extra="<p>Returns an <var>Extended</var> value since the result is not an integer when power <var>N</var> is negative.</p><p>Based on IEEE standard 754-2008 for Floating-Point Arithmetic, page 44, but which restricts <var>X</var> to an integer.</p>"
1229+
Units=SysUtils,
1230+
SeeAlso=Pow,PowN,PowNZN
1231+
TestInfo=advanced
1232+
AdvancedTest.Level=unit-tests
1233+
AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
1234+
Snip=635.dat
1235+
DelphiXE=Y
1236+
Delphi11A=Y
1237+
Delphi12A=Y
1238+
12001239
[ResizeRect_A]
12011240
DisplayName="ResizeRect (TSize overload)"
12021241
DescEx="<p>Resizes rectangle <var>R</var> to size <var>NewSize</var>, leaving the top-left position unchanged.</p><p>Returns the resized rectangle.</p>"

0 commit comments

Comments
(0)

AltStyle によって変換されたページ (->オリジナル) /