Generate and return the value of the optional input argument if it is present, otherwise, return the input default value. More...

Detailed Description

Generate and return the value of the optional input argument if it is present, otherwise, return the input default value.

Parameters

[in]

default

: The input scalar, are array of arbitrary rank, of either

type character of kind any supported by the processor (e.g., SK, SKA, SKD , or SKU), or
type logical of kind any supported by the processor (e.g., LK), or
type integer of kind any supported by the processor (e.g., IK, IK8, IK16, IK32, or IK64), or
type complex of kind any supported by the processor (e.g., CK, CK32, CK64, or CK128), or
type real of kind any supported by the processor (e.g., RK, RK32, RK64, or RK128),

or,

a scalar assumed-length character of kind any supported by the processor (e.g., SK, SKA, SKD , or SKU),

whose value will be returned as the output if optional is missing among the input arguments.

[in] optional : The input value of the same type, kind, and rank as the input default argument, representing the optional input argument whose value will be returned if present.
(optional, default = default)

Returns

value : The output value of the same type, kind, and rank as the input default.

If optional is present as an input argument, value takes the value of optional.
If optional is missing as an input argument, value takes the value of default.

If value is of type character, then its length type parameter is len(default).

Possible calling interfaces ⛓

: use pm_option, only: getOption

defaultValue = getOption(default, optional)

pm_option::getOption
Generate and return the value of the optional input argument if it is present, otherwise,...
Definition: pm_option.F90:135

pm_option
This module contains procedures, generic interfaces, and types for generating default values for opti...
Definition: pm_option.F90:34

Warning: The condition len(optional) <= len(default) must hold when the input arguments are of type character.
This is to ensure proper full assignment of the optional value to the output whose length is that of default.
This condition is verified only if the library is built with the preprocessor macro CHECK_ENABLED=1.; The pure procedure(s) documented herein become impure when the ParaMonte library is compiled with preprocessor macro CHECK_ENABLED=1.
By default, these procedures are pure in release build and impure in debug and testing builds.

Remarks: The procedures under discussion are elemental.

Note: The functions under this generic interface provide are solely intended to a provide convenient shortcut to evaluating whether an optional argument is present or not, and if missing, to return a default value.
Due to significant performance penalty associated with the use of these procedures, their usage should be limited to non-performance-critical sections of code.

Example usage ⛓

: 1program example

2

3 use pm_kind, only: LK

4 use pm_kind, only: SK ! All kinds are supported.

5 use pm_kind, only: IK ! All kinds are supported.

6 use pm_kind, only: CK ! All kinds are supported.

7 use pm_kind, only: RK ! All kinds are supported.

8 use pm_io, only: display_type

9 use pm_option, only: getOption

10

11 implicit none

12

13 character(3, SK), allocatable :: Optional_SK(:,:), Default_SK(:,:), Output_SK(:,:) ! Can be any processor-supported kind.

14 logical(LK) , allocatable :: Optional_LK(:,:), Default_LK(:,:) ! Can be any processor-supported kind.

15 integer(IK) , allocatable :: Optional_IK(:,:), Default_IK(:,:) ! Can be any processor-supported kind.

16 complex(CK) , allocatable :: Optional_CK(:,:), Default_CK(:,:) ! Can be any processor-supported kind.

17 real(RK) , allocatable :: Optional_RK(:,:), Default_RK(:,:) ! Can be any processor-supported kind.

18

19 integer(IK) :: i, j

20

21 type(display_type) :: disp

22 disp = display_type(file = "main.out.F90")

23

24 call disp%skip()

25 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

26 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

27 call disp%show("! Return the optional value if present, otherwise the default value.")

28 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

29 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

30 call disp%skip()

31

32 Optional_SK = reshape(["AAA", "BBB", "CCC", "DDD", "EEE", "FFF"], shape = [2,3])

33 Optional_IK = reshape([1_IK, 2_IK, 3_IK, 4_IK, 5_IK, 6_IK], shape = [2,3])

34 Optional_RK = reshape([1._RK, 2._RK, 3._RK, 4._RK, 5._RK, 6._RK], shape = [2,3])

35 Optional_CK = reshape([(1._CK, -1._CK), (2._CK, -2._CK), (3._CK, -3._CK), (4._CK, -4._CK), (5._CK, -5._CK), (6._CK, -6._CK)], shape = [2,3])

36 Optional_LK = reshape([.false._LK, .true._LK, .false._LK, .true._LK, .false._LK, .true._LK], shape = [2,3])

37

38 Default_SK = reshape([((Optional_SK(i,j), i = size(Optional_SK,1), 1, -1), j = size(Optional_SK,2), 1, -1)], shape = shape(Optional_SK))

39 Default_IK = reshape([((Optional_IK(i,j), i = size(Optional_IK,1), 1, -1), j = size(Optional_IK,2), 1, -1)], shape = shape(Optional_IK))

40 Default_RK = reshape([((Optional_RK(i,j), i = size(Optional_RK,1), 1, -1), j = size(Optional_RK,2), 1, -1)], shape = shape(Optional_RK))

41 Default_CK = reshape([((Optional_CK(i,j), i = size(Optional_CK,1), 1, -1), j = size(Optional_CK,2), 1, -1)], shape = shape(Optional_CK))

42 Default_LK = reshape([((Optional_LK(i,j), i = size(Optional_LK,1), 1, -1), j = size(Optional_LK,2), 1, -1)], shape = shape(Optional_LK))

43

44 call disp%skip()

45 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

46 call disp%show("! Option character scalar/array.")

47 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

48 call disp%skip()

49

50 allocate(Output_SK, mold = Optional_SK)

51

52 call disp%skip()

53 call disp%show("Default_SK")

54 call disp%show( Default_SK, deliml = SK_"""" )

55 call disp%show("Optional_SK")

56 call disp%show( Optional_SK, deliml = SK_"""" )

57 call disp%show("Output_SK(:,:) = getOption(Default_SK)")

58 Output_SK(:,:) = getOption(Default_SK) ! bypass gfortran 10.3 bug

59 call disp%show("Output_SK(:,:)")

60 call disp%show( Output_SK(:,:), deliml = SK_"""" )

61 call disp%show("Output_SK(:,:) = getOption(Default_SK, Optional_SK)")

62 Output_SK(:,:) = getOption(Default_SK, Optional_SK) ! bypass gfortran 10.3 bug

63 call disp%show("Output_SK(:,:)")

64 call disp%show( Output_SK(:,:), deliml = SK_"""" )

65 call disp%skip()

66

67 call disp%skip()

68 call disp%show("Default_SK(:,1)")

69 call disp%show( Default_SK(:,1), deliml = SK_"""" )

70 call disp%show("Optional_SK(:,1)")

71 call disp%show( Optional_SK(:,1), deliml = SK_"""" )

72 call disp%show("Output_SK(:,1) = getOption(Default_SK(:,1))")

73 Output_SK(:,1) = getOption(Default_SK(:,1)) ! bypass gfortran 10.3 bug

74 call disp%show("Output_SK(:,1)")

75 call disp%show( Output_SK(:,1), deliml = SK_"""" )

76 call disp%show("Output_SK(:,1) = getOption(Default_SK(:,1), Optional_SK(:,1))")

77 Output_SK(:,1) = getOption(Default_SK(:,1), Optional_SK(:,1)) ! bypass gfortran 10.3 bug

78 call disp%show("Output_SK(:,1)")

79 call disp%show( Output_SK(:,1), deliml = SK_"""" )

80 call disp%skip()

81

82 call disp%skip()

83 call disp%show("Default_SK(1,1)")

84 call disp%show( Default_SK(1,1), deliml = SK_"""" )

85 call disp%show("Optional_SK(1,1)")

86 call disp%show( Optional_SK(1,1), deliml = SK_"""" )

87 call disp%show("Output_SK(1,1) = getOption(Default_SK(1,1))")

88 Output_SK(1,1) = getOption(Default_SK(1,1)) ! bypass gfortran 10.3 bug

89 call disp%show("Output_SK(1,1)")

90 call disp%show( Output_SK(1,1), deliml = SK_"""" )

91 call disp%show("Output_SK(1,1) = getOption(Default_SK(1,1), Optional_SK(1,1))")

92 Output_SK(1,1) = getOption(Default_SK(1,1), Optional_SK(1,1)) ! bypass gfortran 10.3 bug

93 call disp%show("Output_SK(1,1)")

94 call disp%show( Output_SK(1,1), deliml = SK_"""" )

95 call disp%skip()

96

97 call disp%skip()

98 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

99 call disp%show("! Option logical scalar/array.")

100 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

101 call disp%skip()

102

103 call disp%skip()

104 call disp%show("Default_LK")

105 call disp%show( Default_LK )

106 call disp%show("Optional_LK")

107 call disp%show( Optional_LK )

108 call disp%show("getOption(Default_LK)")

109 call disp%show( getOption(Default_LK) )

110 call disp%show("getOption(Default_LK, Optional_LK)")

111 call disp%show( getOption(Default_LK, Optional_LK) )

112 call disp%skip()

113

114 call disp%skip()

115 call disp%show("Default_LK(:,1)")

116 call disp%show( Default_LK(:,1) )

117 call disp%show("Optional_LK(:,1)")

118 call disp%show( Optional_LK(:,1) )

119 call disp%show("getOption(Default_LK(:,1))")

120 call disp%show( getOption(Default_LK(:,1)) )

121 call disp%show("getOption(Default_LK(:,1), Optional_LK(:,1))")

122 call disp%show( getOption(Default_LK(:,1), Optional_LK(:,1)) )

123 call disp%skip()

124

125 call disp%skip()

126 call disp%show("Default_LK(1,:)")

127 call disp%show( Default_LK(1,:) )

128 call disp%show("Optional_LK(1,:)")

129 call disp%show( Optional_LK(1,:) )

130 call disp%show("getOption(Default_LK(1,:))")

131 call disp%show( getOption(Default_LK(1,:)) )

132 call disp%show("getOption(Default_LK(1,:), Optional_LK(1,:))")

133 call disp%show( getOption(Default_LK(1,:), Optional_LK(1,:)) )

134 call disp%skip()

135

136 call disp%skip()

137 call disp%show("Default_LK(1,1)")

138 call disp%show( Default_LK(1,1) )

139 call disp%show("Optional_LK(1,1)")

140 call disp%show( Optional_LK(1,1) )

141 call disp%show("getOption(Default_LK(1,1))")

142 call disp%show( getOption(Default_LK(1,1)) )

143 call disp%show("getOption(Default_LK(1,1), Optional_LK(1,1))")

144 call disp%show( getOption(Default_LK(1,1), Optional_LK(1,1)) )

145 call disp%skip()

146

147 call disp%skip()

148 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

149 call disp%show("! Option integer scalar/array.")

150 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

151 call disp%skip()

152

153 call disp%skip()

154 call disp%show("Default_IK")

155 call disp%show( Default_IK )

156 call disp%show("Optional_IK")

157 call disp%show( Optional_IK )

158 call disp%show("getOption(Default_IK)")

159 call disp%show( getOption(Default_IK) )

160 call disp%show("getOption(Default_IK, Optional_IK)")

161 call disp%show( getOption(Default_IK, Optional_IK) )

162 call disp%skip()

163

164 call disp%skip()

165 call disp%show("Default_IK(:,1)")

166 call disp%show( Default_IK(:,1) )

167 call disp%show("Optional_IK(:,1)")

168 call disp%show( Optional_IK(:,1) )

169 call disp%show("getOption(Default_IK(:,1))")

170 call disp%show( getOption(Default_IK(:,1)) )

171 call disp%show("getOption(Default_IK(:,1), Optional_IK(:,1))")

172 call disp%show( getOption(Default_IK(:,1), Optional_IK(:,1)) )

173 call disp%skip()

174

175 call disp%skip()

176 call disp%show("Default_IK(1,:)")

177 call disp%show( Default_IK(1,:) )

178 call disp%show("Optional_IK(1,:)")

179 call disp%show( Optional_IK(1,:) )

180 call disp%show("getOption(Default_IK(1,:))")

181 call disp%show( getOption(Default_IK(1,:)) )

182 call disp%show("getOption(Default_IK(1,:), Optional_IK(1,:))")

183 call disp%show( getOption(Default_IK(1,:), Optional_IK(1,:)) )

184 call disp%skip()

185

186 call disp%skip()

187 call disp%show("Default_IK(1,1)")

188 call disp%show( Default_IK(1,1) )

189 call disp%show("Optional_IK(1,1)")

190 call disp%show( Optional_IK(1,1) )

191 call disp%show("getOption(Default_IK(1,1))")

192 call disp%show( getOption(Default_IK(1,1)) )

193 call disp%show("getOption(Default_IK(1,1), Optional_IK(1,1))")

194 call disp%show( getOption(Default_IK(1,1), Optional_IK(1,1)) )

195 call disp%skip()

196

197 call disp%skip()

198 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

199 call disp%show("! Option complex scalar/array.")

200 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%")

201 call disp%skip()

202

203 call disp%skip()

204 call disp%show("Default_CK")

205 call disp%show( Default_CK )

206 call disp%show("Optional_CK")

207 call disp%show( Optional_CK )

208 call disp%show("getOption(Default_CK)")

209 call disp%show( getOption(Default_CK) )

210 call disp%show("getOption(Default_CK, Optional_CK)")

211 call disp%show( getOption(Default_CK, Optional_CK) )

212 call disp%skip()

213

214 call disp%skip()

215 call disp%show("Default_CK(:,1)")

216 call disp%show( Default_CK(:,1) )

217 call disp%show("Optional_CK(:,1)")

218 call disp%show( Optional_CK(:,1) )

219 call disp%show("getOption(Default_CK(:,1))")

220 call disp%show( getOption(Default_CK(:,1)) )

221 call disp%show("getOption(Default_CK(:,1), Optional_CK(:,1))")

222 call disp%show( getOption(Default_CK(:,1), Optional_CK(:,1)) )

223 call disp%skip()

224

225 call disp%skip()

226 call disp%show("Default_CK(1,:)")

227 call disp%show( Default_CK(1,:) )

228 call disp%show("Optional_CK(1,:)")

229 call disp%show( Optional_CK(1,:) )

230 call disp%show("getOption(Default_CK(1,:))")

231 call disp%show( getOption(Default_CK(1,:)) )

232 call disp%show("getOption(Default_CK(1,:), Optional_CK(1,:))")

233 call disp%show( getOption(Default_CK(1,:), Optional_CK(1,:)) )

234 call disp%skip()

235

236 call disp%skip()

237 call disp%show("Default_CK(1,1)")

238 call disp%show( Default_CK(1,1) )

239 call disp%show("Optional_CK(1,1)")

240 call disp%show( Optional_CK(1,1) )

241 call disp%show("getOption(Default_CK(1,1))")

242 call disp%show( getOption(Default_CK(1,1)) )

243 call disp%show("getOption(Default_CK(1,1), Optional_CK(1,1))")

244 call disp%show( getOption(Default_CK(1,1), Optional_CK(1,1)) )

245 call disp%skip()

246

247 call disp%skip()

248 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%")

249 call disp%show("! Option real scalar/array.")

250 call disp%show("!%%%%%%%%%%%%%%%%%%%%%%%%%%")

251 call disp%skip()

252

253 call disp%skip()

254 call disp%show("Default_RK")

255 call disp%show( Default_RK )

256 call disp%show("Optional_RK")

257 call disp%show( Optional_RK )

258 call disp%show("getOption(Default_RK)")

259 call disp%show( getOption(Default_RK) )

260 call disp%show("getOption(Default_RK, Optional_RK)")

261 call disp%show( getOption(Default_RK, Optional_RK) )

262 call disp%skip()

263

264 call disp%skip()

265 call disp%show("Default_RK(:,1)")

266 call disp%show( Default_RK(:,1) )

267 call disp%show("Optional_RK(:,1)")

268 call disp%show( Optional_RK(:,1) )

269 call disp%show("getOption(Default_RK(:,1))")

270 call disp%show( getOption(Default_RK(:,1)) )

271 call disp%show("getOption(Default_RK(:,1), Optional_RK(:,1))")

272 call disp%show( getOption(Default_RK(:,1), Optional_RK(:,1)) )

273 call disp%skip()

274

275 call disp%skip()

276 call disp%show("Default_RK(1,:)")

277 call disp%show( Default_RK(1,:) )

278 call disp%show("Optional_RK(1,:)")

279 call disp%show( Optional_RK(1,:) )

280 call disp%show("getOption(Default_RK(1,:))")

281 call disp%show( getOption(Default_RK(1,:)) )

282 call disp%show("getOption(Default_RK(1,:), Optional_RK(1,:))")

283 call disp%show( getOption(Default_RK(1,:), Optional_RK(1,:)) )

284 call disp%skip()

285

286 call disp%skip()

287 call disp%show("Default_RK(1,1)")

288 call disp%show( Default_RK(1,1) )

289 call disp%show("Optional_RK(1,1)")

290 call disp%show( Optional_RK(1,1) )

291 call disp%show("getOption(Default_RK(1,1))")

292 call disp%show( getOption(Default_RK(1,1)) )

293 call disp%show("getOption(Default_RK(1,1), Optional_RK(1,1))")

294 call disp%show( getOption(Default_RK(1,1), Optional_RK(1,1)) )

295 call disp%skip()

296

297end program example

pm_io::show
This is a generic method of the derived type display_type with pass attribute.
Definition: pm_io.F90:11726

pm_io::skip
This is a generic method of the derived type display_type with pass attribute.
Definition: pm_io.F90:11508

pm_io
This module contains classes and procedures for input/output (IO) or generic display operations on st...
Definition: pm_io.F90:252

pm_io::disp
type(display_type) disp
This is a scalar module variable an object of type display_type for general display.
Definition: pm_io.F90:11393

pm_kind
This module defines the relevant Fortran kind type-parameters frequently used in the ParaMonte librar...
Definition: pm_kind.F90:268

pm_kind::RK
integer, parameter RK
The default real kind in the ParaMonte library: real64 in Fortran, c_double in C-Fortran Interoperati...
Definition: pm_kind.F90:543

pm_kind::LK
integer, parameter LK
The default logical kind in the ParaMonte library: kind(.true.) in Fortran, kind(....
Definition: pm_kind.F90:541

pm_kind::CK
integer, parameter CK
The default complex kind in the ParaMonte library: real64 in Fortran, c_double_complex in C-Fortran I...
Definition: pm_kind.F90:542

pm_kind::IK
integer, parameter IK
The default integer kind in the ParaMonte library: int32 in Fortran, c_int32_t in C-Fortran Interoper...
Definition: pm_kind.F90:540

pm_kind::SK
integer, parameter SK
The default character kind in the ParaMonte library: kind("a") in Fortran, c_char in C-Fortran Intero...
Definition: pm_kind.F90:539

pm_io::display_type
Generate and return an object of type display_type.
Definition: pm_io.F90:10282

Example Unix compile command via Intel ifort compiler ⛓
1#!/usr/bin/env sh

2rm main.exe

3ifort -fpp -standard-semantics -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe

4./main.exe

Example Windows Batch compile command via Intel ifort compiler ⛓
1del main.exe

2set PATH=..\..\..\lib;%PATH%

3ifort /fpp /standard-semantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe

4main.exe

Example Unix / MinGW compile command via GNU gfortran compiler ⛓
1#!/usr/bin/env sh

2rm main.exe

3gfortran -cpp -ffree-line-length-none -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe

4./main.exe

Example output ⛓
1

2!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

3!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

4! Return the optional value if present, otherwise the default value.

5!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

6!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

7

8

9!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

10! Option character scalar/array.

11!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

12

13

14Default_SK

15"FFF", "DDD", "BBB"

16"EEE", "CCC", "AAA"

17Optional_SK

18"AAA", "CCC", "EEE"

19"BBB", "DDD", "FFF"

20Output_SK(:,:) = getOption(Default_SK)

21Output_SK(:,:)

22"FFF", "DDD", "BBB"

23"EEE", "CCC", "AAA"

24Output_SK(:,:) = getOption(Default_SK, Optional_SK)

25Output_SK(:,:)

26"AAA", "CCC", "EEE"

27"BBB", "DDD", "FFF"

28

29

30Default_SK(:,1)

31"FFF", "EEE"

32Optional_SK(:,1)

33"AAA", "BBB"

34Output_SK(:,1) = getOption(Default_SK(:,1))

35Output_SK(:,1)

36"FFF", "EEE"

37Output_SK(:,1) = getOption(Default_SK(:,1), Optional_SK(:,1))

38Output_SK(:,1)

39"AAA", "BBB"

40

41

42Default_SK(1,1)

43"FFF"

44Optional_SK(1,1)

45"AAA"

46Output_SK(1,1) = getOption(Default_SK(1,1))

47Output_SK(1,1)

48"FFF"

49Output_SK(1,1) = getOption(Default_SK(1,1), Optional_SK(1,1))

50Output_SK(1,1)

51"AAA"

52

53

54!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

55! Option logical scalar/array.

56!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

57

58

59Default_LK

60T, T, T

61F, F, F

62Optional_LK

63F, F, F

64T, T, T

65getOption(Default_LK)

66T, T, T

67F, F, F

68getOption(Default_LK, Optional_LK)

69F, F, F

70T, T, T

71

72

73Default_LK(:,1)

74T, F

75Optional_LK(:,1)

76F, T

77getOption(Default_LK(:,1))

78T, F

79getOption(Default_LK(:,1), Optional_LK(:,1))

80F, T

81

82

83Default_LK(1,:)

84T, T, T

85Optional_LK(1,:)

86F, F, F

87getOption(Default_LK(1,:))

88T, T, T

89getOption(Default_LK(1,:), Optional_LK(1,:))

90F, F, F

91

92

93Default_LK(1,1)

94T

95Optional_LK(1,1)

96F

97getOption(Default_LK(1,1))

98T

99getOption(Default_LK(1,1), Optional_LK(1,1))

100F

101

102

103!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

104! Option integer scalar/array.

105!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

106

107

108Default_IK

109+6, +4, +2

110+5, +3, +1

111Optional_IK

112+1, +3, +5

113+2, +4, +6

114getOption(Default_IK)

115+6, +4, +2

116+5, +3, +1

117getOption(Default_IK, Optional_IK)

118+1, +3, +5

119+2, +4, +6

120

121

122Default_IK(:,1)

123+6, +5

124Optional_IK(:,1)

125+1, +2

126getOption(Default_IK(:,1))

127+6, +5

128getOption(Default_IK(:,1), Optional_IK(:,1))

129+1, +2

130

131

132Default_IK(1,:)

133+6, +4, +2

134Optional_IK(1,:)

135+1, +3, +5

136getOption(Default_IK(1,:))

137+6, +4, +2

138getOption(Default_IK(1,:), Optional_IK(1,:))

139+1, +3, +5

140

141

142Default_IK(1,1)

143+6

144Optional_IK(1,1)

145+1

146getOption(Default_IK(1,1))

147+6

148getOption(Default_IK(1,1), Optional_IK(1,1))

149+1

150

151

152!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

153! Option complex scalar/array.

154!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

155

156

157Default_CK

158(+6.0000000000000000, -6.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

159(+5.0000000000000000, -5.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+1.0000000000000000, -1.0000000000000000)

160Optional_CK

161(+1.0000000000000000, -1.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

162(+2.0000000000000000, -2.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+6.0000000000000000, -6.0000000000000000)

163getOption(Default_CK)

164(+6.0000000000000000, -6.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

165(+5.0000000000000000, -5.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+1.0000000000000000, -1.0000000000000000)

166getOption(Default_CK, Optional_CK)

167(+1.0000000000000000, -1.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

168(+2.0000000000000000, -2.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+6.0000000000000000, -6.0000000000000000)

169

170

171Default_CK(:,1)

172(+6.0000000000000000, -6.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

173Optional_CK(:,1)

174(+1.0000000000000000, -1.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

175getOption(Default_CK(:,1))

176(+6.0000000000000000, -6.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

177getOption(Default_CK(:,1), Optional_CK(:,1))

178(+1.0000000000000000, -1.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

179

180

181Default_CK(1,:)

182(+6.0000000000000000, -6.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

183Optional_CK(1,:)

184(+1.0000000000000000, -1.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

185getOption(Default_CK(1,:))

186(+6.0000000000000000, -6.0000000000000000), (+4.0000000000000000, -4.0000000000000000), (+2.0000000000000000, -2.0000000000000000)

187getOption(Default_CK(1,:), Optional_CK(1,:))

188(+1.0000000000000000, -1.0000000000000000), (+3.0000000000000000, -3.0000000000000000), (+5.0000000000000000, -5.0000000000000000)

189

190

191Default_CK(1,1)

192(+6.0000000000000000, -6.0000000000000000)

193Optional_CK(1,1)

194(+1.0000000000000000, -1.0000000000000000)

195getOption(Default_CK(1,1))

196(+6.0000000000000000, -6.0000000000000000)

197getOption(Default_CK(1,1), Optional_CK(1,1))

198(+1.0000000000000000, -1.0000000000000000)

199

200

201!%%%%%%%%%%%%%%%%%%%%%%%%%%

202! Option real scalar/array.

203!%%%%%%%%%%%%%%%%%%%%%%%%%%

204

205

206Default_RK

207+6.0000000000000000, +4.0000000000000000, +2.0000000000000000

208+5.0000000000000000, +3.0000000000000000, +1.0000000000000000

209Optional_RK

210+1.0000000000000000, +3.0000000000000000, +5.0000000000000000

211+2.0000000000000000, +4.0000000000000000, +6.0000000000000000

212getOption(Default_RK)

213+6.0000000000000000, +4.0000000000000000, +2.0000000000000000

214+5.0000000000000000, +3.0000000000000000, +1.0000000000000000

215getOption(Default_RK, Optional_RK)

216+1.0000000000000000, +3.0000000000000000, +5.0000000000000000

217+2.0000000000000000, +4.0000000000000000, +6.0000000000000000

218

219

220Default_RK(:,1)

221+6.0000000000000000, +5.0000000000000000

222Optional_RK(:,1)

223+1.0000000000000000, +2.0000000000000000

224getOption(Default_RK(:,1))

225+6.0000000000000000, +5.0000000000000000

226getOption(Default_RK(:,1), Optional_RK(:,1))

227+1.0000000000000000, +2.0000000000000000

228

229

230Default_RK(1,:)

231+6.0000000000000000, +4.0000000000000000, +2.0000000000000000

232Optional_RK(1,:)

233+1.0000000000000000, +3.0000000000000000, +5.0000000000000000

234getOption(Default_RK(1,:))

235+6.0000000000000000, +4.0000000000000000, +2.0000000000000000

236getOption(Default_RK(1,:), Optional_RK(1,:))

237+1.0000000000000000, +3.0000000000000000, +5.0000000000000000

238

239

240Default_RK(1,1)

241+6.0000000000000000

242Optional_RK(1,1)

243+1.0000000000000000

244getOption(Default_RK(1,1))

245+6.0000000000000000

246getOption(Default_RK(1,1), Optional_RK(1,1))

247+1.0000000000000000

248

249

Benchmarks:

Benchmark :: The runtime performance of getOption vs. direct optional choice ⛓

program benchmark
 
    use iso_fortran_env, only: error_unit
    use pm_bench, only: bench_type
    use pm_kind, only: IK, RK, SK
 
    implicit none
 
    integer(IK)                         :: i
    integer(IK)                         :: isize
    integer(IK)                         :: fileUnit
    integer(IK) , parameter             :: NSIZE = 14_IK
    integer(IK) , parameter             :: NBENCH = 2_IK
    integer(IK)                         :: arraySize(0:NSIZE)
    real(RK)                            :: dummy = 0._RK
    real(RK)                            :: unifrnd
    real(RK)    , allocatable           :: Array(:)
    real(RK)    , allocatable           :: Default(:)
    type(bench_type)                    :: bench(NBENCH)
 
    bench(1) = bench_type(name = SK_"getOption", exec = getOption , overhead = setOverhead)
    bench(2) = bench_type(name = SK_"direct", exec = direct , overhead = setOverhead)
 
    arraySize = [0_IK, ( 2_IK**isize, isize = 0_IK, NSIZE - 1_IK)]
 
    write(*,"(*(g0,:,' '))")
    write(*,"(*(g0,:,' '))") "getOption() vs. direct()"
    write(*,"(*(g0,:,' '))")
 
    open(newunit = fileUnit, file = "main.out", status = "replace")
 
        write(fileUnit, "(*(g0,:,','))") "arraySize", (bench(i)%name, i = 1, NBENCH)
 
        loopOverArraySize: do isize = 0_IK, NSIZE
 
            write(*,"(*(g0,:,' '))") "Benchmarking with size", arraySize(isize)
 
            allocate(Array(arraySize(isize)), Default(arraySize(isize)))
            call random_number(Default)
            call random_number(Array)
            do i = 1, NBENCH
                bench(i)%timing = bench(i)%getTiming(minsec = 0.07_RK)
            end do
            deallocate(Array, Default)
 
            write(fileUnit,"(*(g0,:,','))") arraySize(isize), (bench(i)%timing%mean, i = 1, NBENCH)
 
        end do loopOverArraySize
        write(*,"(*(g0,:,' '))") dummy
        write(*,"(*(g0,:,' '))")
 
    close(fileUnit)
 
contains
 
    !%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    ! procedure wrappers.
    !%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
    subroutine setOverhead()
        call random_number(unifrnd)
        if (arraySize(isize) > 0_IK) then
            !if (unifrnd < 0.5_RK) then
            !    call addOverhead_D1()
            !else
            !    call addOverhead_D1()
            !end if
            dummy = dummy + sum(Default)
        else
            dummy = dummy + unifrnd
            !if (unifrnd < 0.5_RK) then
            !    call addOverhead_D0()
            !else
            !    call addOverhead_D0()
            !end if
        end if
    end subroutine
 
    !subroutine addOverhead_D0()
    !    dummy = dummy + unifrnd
    !end subroutine
    !
    !subroutine addOverhead_D1()
    !    dummy = dummy + sum(Default)
    !end subroutine
 
    subroutine getOption()
        call random_number(unifrnd)
        if (arraySize(isize) > 0_IK) then
            if (unifrnd < 0.5_RK) then
                call add_option_D1(Array)
            else
                call add_option_D1()
            end if
        else
            if (unifrnd < 0.5_RK) then
                call add_option_D0(unifrnd)
            else
                call add_option_D0()
            end if
        end if
    end subroutine
 
    subroutine direct()
        call random_number(unifrnd)
        if (arraySize(isize) > 0_IK) then
            if (unifrnd < 0.5_RK) then
                call add_direct_D1(Array)
            else
                call add_direct_D1()
            end if
        else
            if (unifrnd < 0.5_RK) then
                call add_direct_D0(unifrnd)
            else
                call add_direct_D0()
            end if
        end if
    end subroutine
 
    subroutine add_option_D0(value)
        use pm_option, only: getOption
        real(RK), intent(in), optional :: value
        dummy = dummy + getOption(unifrnd, value)
    end subroutine
 
    subroutine add_direct_D0(value)
        real(RK), intent(in), optional :: value
        if (present(value)) then
            dummy = dummy + value
        else
            dummy = dummy + unifrnd
        end if
    end subroutine
 
    subroutine add_option_D1(Value)
        use pm_option, only: getOption
        real(RK), intent(in), optional :: Value(:)
        dummy = dummy + sum(getOption(Default, Value))
    end subroutine
 
    subroutine add_direct_D1(Value)
        real(RK), intent(in), optional :: Value(:)
        if (present(Value)) then
            dummy = dummy + sum(Value)
        else
            dummy = dummy + sum(Default)
        end if
    end subroutine
 
end program benchmark

Example Unix compile command via Intel ifort compiler ⛓

#!/usr/bin/env sh
rm main.exe
ifort -fpp -standard-semantics -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Example Windows Batch compile command via Intel ifort compiler ⛓

del main.exe
set PATH=..\..\..\lib;%PATH%
ifort /fpp /standard-semantics /O3 /I:..\..\..\include main.F90 ..\..\..\lib\libparamonte*.lib /exe:main.exe
main.exe

Example Unix / MinGW compile command via GNU gfortran compiler ⛓

#!/usr/bin/env sh
rm main.exe
gfortran -cpp -ffree-line-length-none -O3 -Wl,-rpath,../../../lib -I../../../inc main.F90 ../../../lib/libparamonte* -o main.exe
./main.exe

Postprocessing of the benchmark output ⛓

#!/usr/bin/env python
 
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
 
fontsize = 14
 
methods = ["direct", "getOption"]
 
df = pd.read_csv("main.out")
 
 
 
ax = plt.figure(figsize = 1.25 * np.array([6.4,4.6]), dpi = 200)
ax = plt.subplot()
 
for method in methods:
    plt.plot( df["arraySize"].values + 1
            , df[method].values
            , linewidth = 2
            )
 
plt.xticks(fontsize = fontsize)
plt.yticks(fontsize = fontsize)
ax.set_xlabel("Array Size + 1", fontsize = fontsize)
ax.set_ylabel("Runtime [ seconds ]", fontsize = fontsize)
ax.set_title("getOption() vs. direct method.\nLower is better.", fontsize = fontsize)
ax.set_xscale("log")
ax.set_yscale("log")
plt.minorticks_on()
plt.grid(visible = True, which = "both", axis = "both", color = "0.85", linestyle = "-")
ax.tick_params(axis = "y", which = "minor")
ax.tick_params(axis = "x", which = "minor")
ax.legend   ( methods
           #, loc='center left'
           #, bbox_to_anchor=(1, 0.5)
            , fontsize = fontsize
            )
 
plt.tight_layout()
plt.savefig("benchmark.getOption_vs_direct.runtime.png")
 
 
 
ax = plt.figure(figsize = 1.25 * np.array([6.4,4.6]), dpi = 200)
ax = plt.subplot()
 
plt.plot( df["arraySize"].values + 1
        , np.ones(len(df["arraySize"].values))
       #, linestyle = "--"
        , linewidth = 2
        )
plt.plot( df["arraySize"].values + 1
        , df["getOption"].values / df["direct"].values
        , linewidth = 2
        )
 
plt.xticks(fontsize = fontsize)
plt.yticks(fontsize = fontsize)
ax.set_xlabel("Array Size + 1", fontsize = fontsize)
ax.set_ylabel("getOption() runtime compared to direct method", fontsize = fontsize)
ax.set_title("getOption() to direct method Runtime Ratio.\nLower means faster. Lower than 1 means faster than direct method.", fontsize = fontsize)
ax.set_xscale("log")
ax.set_yscale("log")
plt.minorticks_on()
plt.grid(visible = True, which = "both", axis = "both", color = "0.85", linestyle = "-")
ax.tick_params(axis = "y", which = "minor")
ax.tick_params(axis = "x", which = "minor")
ax.legend   ( ["Direct Method (Equality)", "getOption()"]
           #, bbox_to_anchor = (1, 0.5)
           #, loc = "center left"
            , fontsize = fontsize
            )
 
plt.tight_layout()
plt.savefig("benchmark.getOption_vs_direct.runtime.ratio.png")

Visualization of the benchmark output ⛓

Benchmark moral ⛓

The benchmark results indicate that explicit if-blocks for optional arguments tends to be 100-1000 times faster than calling the convenience functions under the generic interface getOption.
This performance difference tends to be about a factor of 10 times for scalar optional arguments and grows substantially to larger factors with switching to increasing-size array-like optional dummy arguments.
Despite significant performance degradation with the use of getOption, note that the overall average overhead of calling getOption remains extremely small as of 2022 AD, on the order of nano to micro seconds depending on the size of the optional argument from scalar to large arrays.
Additionally, the significance of performance degradation, if any, depends entirely on the ability of the compiler to inline the procedure.
The observed performance degradations report here occur without any compiler inlining attempts.
Consequently, there is practically no harm in using getOption in non-performance-critical sections of a codebase, that is, parts of a codebase that are to be called less than billions of times at runtime.

Test:: test_pm_option

Final Remarks ⛓

If you believe this algorithm or its documentation can be improved, we appreciate your contribution and help to edit this page's documentation and source file on GitHub.
For details on the naming abbreviations, see this page.
For details on the naming conventions, see this page.
This software is distributed under the MIT license with additional terms outlined below.

If you use any parts or concepts from this library to any extent, please acknowledge the usage by citing the relevant publications of the ParaMonte library.
If you regenerate any parts/ideas from this library in a programming environment other than those currently supported by this ParaMonte library (i.e., other than C, C++, Fortran, MATLAB, Python, R), please also ask the end users to cite this original ParaMonte library.

This software is available to the public under a highly permissive license.
Help us justify its continued development and maintenance by acknowledging its benefit to society, distributing it, and contributing to it.

Copyright: Computational Data Science Lab The functions under the generic interface getOption are inspired by and further extend the functionalities implemented in optval of the Fortran stdlib.

Author:: Amir Shahmoradi, September 1, 2020, 01:12 AM, Dallas, Texas

Definition at line 135 of file pm_option.F90.

The documentation for this interface was generated from the following file:

src/fortran/main/pm_option.F90