[U] User's Guide

More documents

Recommendations

Info

66 [ U ] 6 Setting the size of memory. use regsmpl(NLS Women 14-26 in 1968). memorybytesDetails of set memory usageoverhead (pointers) 114,136 10.88%data 913,088 87.08%data + overhead 1,027,224 97.96%free 21,344 2.04%Total allocated 1,048,568 100.00%Other memory usagesystem overhead 677,289set matsize usage 16,320programs, saved results, etc. 505Total 694,114Grand total 1,742,682Having 21,344 bytes free is not much. You might increase the amount of memory allocated to Stata’sdata areas by specifying set memory 2m.. save regsmplfile regsmpl.dta saved. clear. set memory 2m(2048k). use regsmpl(NLS Women 14-26 in 1968). memorybytesDetails of set memory usageoverhead (pointers) 114,136 5.44%data 913,088 43.54%data + overhead 1,027,224 48.98%free 1,069,920 51.02%Total allocated 2,097,144 100.00%Other memory usagesystem overhead 677,289set matsize usage 16,320programs, saved results, etc. 667Total 694,276Grand total 2,791,420More than 1 MB free: that is better. See [D] memory for more information.
6.5 Virtual memory and speed considerations[ U ] 6.6 An issue when returning memory to Unix 67When you use more memory than is physically available on your computer, Stata slows down. Ifyou are only using a little more memory than on your computer, performance is probably not too bad.On the other hand, when you are using a lot more memory than is on your computer, performancewill be noticeably affected. In these cases, we recommend that you. set virtual onVirtual memory systems exploit locality of reference, which means that keeping objects closertogether allows virtual memory systems to run faster. set virtual controls whether Stata shouldperform extra work to arrange its memory to keep objects close together. By default, virtual isset off. set virtual can be used with Stata/MP, Stata/SE, and Stata/IC on all supported operatingsystems.In general, you want to leave set virtual set to the default of off so that Stata will run faster.When you set virtual on, you are asking Stata to arrange its memory so that objects arekept closer together. This requires Stata to do a substantial amount of work. We recommend settingvirtual on only when the amount of memory in use drastically exceeds what is physically available.In these cases, setting virtual on will help, but performance will still be slow. If you are usingvirtual memory often, you should consider adding memory to your computer.6.6 An issue when returning memory to UnixThere is a surprising issue of returning memory that Unix users need to understand. Let’s say thatyou set memory to 128 megabytes, went along for a while, and then, being a good citizen, returnedmost of it:. set memory 2m(2048k)Theoretically, 126 megabytes was returned to the operating system for use by other processes. Ifyou use Mac or Windows, that is exactly what happens and, with some Unix systems, that is whathappens, too.Other Unix systems, however, are strange about returned memory in a misguided effort to beefficient: they do not really take the memory back. Instead, they leave it allocated to you in case youask for it back later. Still other Unix systems sort of take the memory back: they put it in a queuefor your use, but, if you do not ask for it back in 5 or 10 minutes, then they return it to the realsystem pool!The unfortunate situation is that we, at Stata, cannot force the operating system to take the memoryback. Stata returns the memory to Unix, and then Unix does whatever it wants with it.So, let’s review: you make your Stata smaller in an effort to be a good citizen. You return thememory so that other users can use it, or perhaps so you can use it with some other software.If you use Windows, the memory really is returned and all works exactly as you anticipated.If you use Unix, it might go back immediately, it might go back in 5 or 10 minutes, or it mightnever go back. In the last case, the only way to really return the memory is to exit Stata. All Unixsystems agree on that: when a process ends, the memory really does go back into the pool.To find out how your Unix works, you need to experiment. We would publish a table and just tellyou, but we have found that within manufacturer the way their Unix works will vary by subrelease!The experiment is tedious but not difficult:
Page 1 and 2:
A Stata Press PublicationStataCorp
Page 3 and 4:
iTable of contentsStata basics1 Rea
Page 5 and 6:
iii8.2 The return message for obtai
Page 7 and 8:
v14 Matrix expressions . . . . . .
Page 9 and 10:
vii18.11.6 Writing online help . .
Page 11 and 12:
ix25.2.15 Treatment of empty cells
Page 13:
Stata basics1 Read this—it will h
Page 16 and 17:
4 [ U ] 1 Read this—it will helpA
Page 18 and 19:
6 [ U ] 1 Read this—it will helpW
Page 20 and 21:
8 [ U ] 1 Read this—it will helpW
Page 22 and 23:
10 [ U ] 1 Read this—it will help
Page 24 and 25:
Page 26 and 27:
Page 28 and 29: 16 [ U ] 1 Read this—it will help
Page 48 and 49: 36 [ U ] 2 A brief description of S
Page 50 and 51: 38 [ U ] 2 A brief description of S
Page 52 and 53: 40 [ U ] 3 Resources for learning a
Page 58: 46 [ U ] 3 Resources for learning a
Page 61: [ U ] 4.3 help: Stata’s help syst
Page 64 and 65: 52 [ U ] 4 Stata’s help and searc
Page 70 and 71: 58 [ U ] 5 Flavors of Stata5.2 Stat
Page 72 and 73: 60 [ U ] 5 Flavors of StataThe diff
Page 74 and 75: 62 [ U ] 6 Setting the size of memo
Page 83 and 84: 8 Error messages and return codesCo
Page 85: [ U ] 8.2 The return message for ob
Page 88 and 89: 76 [ U ] 9 The Break key9.2 Side ef
Page 90 and 91: 78 [ U ] 10 Keyboard usesave is the
Page 92 and 93: 80 [ U ] 10 Keyboard use10.4 Editin
Page 94 and 95: 82 [ U ] 10 Keyboard useAnother met
Page 97 and 98: 11 Language syntaxContents11.1 Over
Page 99 and 100: [ U ] 11.1 Overview 8711.1.2 by var
Page 101 and 102: [ U ] 11.1 Overview 89. summarize m
Page 103 and 104: [ U ] 11.1 Overview 91Example 7Nega
Page 105 and 106: 11.1.7 options[ U ] 11.1 Overview 9
Page 107 and 108: [ U ] 11.1 Overview 9511.1.8 numlis
Page 109 and 110: [ U ] 11.2 Abbreviation rules 97by
Page 111 and 112: [ U ] 11.3 Naming conventions 99The
Page 113 and 114: [ U ] 11.4 varlists 101You may use
Page 115 and 116: [ U ] 11.4 varlists 103Consider a v
Page 117 and 118: [ U ] 11.4 varlists 105Here are som
Page 119 and 120: [ U ] 11.4 varlists 107You can sele
Page 121 and 122: [ U ] 11.4 varlists 109. use http:/
Page 123 and 124: [ U ] 11.5 by varlist: construct 11
Page 125 and 126: [ U ] 11.5 by varlist: construct 11
Page 127 and 128: [ U ] 11.6 File-naming conventions
Page 129 and 130:
12 DataContents12.1 Data and datase
Page 131 and 132:
[ U ] 12.2 Numbers 119. display 2/0
Page 133 and 134:
[ U ] 12.2 Numbers 121Technical not
Page 135 and 136:
[ U ] 12.4 Strings 12312.4 StringsA
Page 137 and 138:
[ U ] 12.5 Formats: Controlling how
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
[ U ] 12.6 Dataset, variable, and v
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
[ U ] 12.8 Characteristics 139You c
Page 153:
[ U ] 12.10 References 141The Varia
Page 156 and 157:
144 [ U ] 13 Functions and expressi
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
162 [ U ] 14 Matrix expressionsHere
Page 176 and 177:
164 [ U ] 14 Matrix expressionsWe c
Page 178 and 179:
166 [ U ] 14 Matrix expressions. ma
Page 180 and 181:
168 [ U ] 14 Matrix expressionsRega
Page 182 and 183:
170 [ U ] 14 Matrix expressionsEith
Page 184 and 185:
172 [ U ] 14 Matrix expressionsThe
Page 186 and 187:
174 [ U ] 14 Matrix expressions7. W
Page 188 and 189:
176 [ U ] 15 Saving and printing ou
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
182 [ U ] 16 Do-filesYou then enter
Page 196 and 197:
184 [ U ] 16 Do-files* a sample ana
Page 198 and 199:
186 [ U ] 16 Do-files16.1.4 Error h
Page 200 and 201:
188 [ U ] 16 Do-filesMany users inc
Page 202 and 203:
190 [ U ] 16 Do-files5. If Stata is
Page 204 and 205:
192 [ U ] 16 Do-filesyou could writ
Page 207 and 208:
17 Ado-filesContents17.1 Descriptio
Page 209 and 210:
[ U ] 17.5 Where does Stata look fo
Page 211 and 212:
17.6 How do I install an addition?A
Page 213 and 214:
18 Programming StataContents18.1 De
Page 215 and 216:
[ U ] 18.2 Relationship between a p
Page 217 and 218:
[ U ] 18.3 Macros 205That problem i
Page 219 and 220:
[ U ] 18.3 Macros 207For the right
Page 221 and 222:
[ U ] 18.3 Macros 209To a programme
Page 223 and 224:
[ U ] 18.3 Macros 211Because Stata
Page 225 and 226:
[ U ] 18.3 Macros 213Above we have
Page 227 and 228:
[ U ] 18.3 Macros 21518.3.10 Advanc
Page 229 and 230:
[ U ] 18.4 Program arguments 217You
Page 231 and 232:
[ U ] 18.4 Program arguments 219Let
Page 233 and 234:
[ U ] 18.4 Program arguments 221Equ
Page 235 and 236:
[ U ] 18.4 Program arguments 223pro
Page 237 and 238:
[ U ] 18.4 Program arguments 22518.
Page 239 and 240:
[ U ] 18.7 Temporary objects 22718.
Page 241 and 242:
[ U ] 18.8 Accessing results calcul
Page 243 and 244:
[ U ] 18.9 Accessing results calcul
Page 245 and 246:
[ U ] 18.10 Saving results 2333. Co
Page 247 and 248:
[ U ] 18.10 Saving results 2355. Yo
Page 249 and 250:
[ U ] 18.11 Ado-files 237e(sample)
Page 251 and 252:
[ U ] 18.11 Ado-files 239If you wri
Page 253 and 254:
[ U ] 18.11 Ado-files 241duck is co
Page 255 and 256:
[ U ] 18.11 Ado-files 243begin fvar
Page 257 and 258:
[ U ] 18.11 Ado-files 245begin fvar
Page 259 and 260:
Technical note[ U ] 18.11 Ado-files
Page 261 and 262:
[ U ] 18.11 Ado-files 249{phang}{op
Page 263 and 264:
[ U ] 18.11 Ado-files 2515. Include
Page 265:
[ U ] 18.13 References 253Technical
Page 268 and 269:
256 [ U ] 19 Immediate commands19.1
Page 270 and 271:
258 [ U ] 19 Immediate commands19.1
Page 272 and 273:
260 [ U ] 20 Estimation and postest
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
314
Page 328 and 329:
316 [ U ] 21 Inputting data21.2 Det
Page 330 and 331:
318 [ U ] 21 Inputting dataM,Joe Sm
Page 332 and 333:
320 [ U ] 21 Inputting dataTechnica
Page 334 and 335:
322 [ U ] 21 Inputting dataAnother
Page 337 and 338:
22 Combining datasetsYou have two d
Page 339 and 340:
23 Working with stringsContents23.1
Page 341 and 342:
[ U ] 23.4 Complex strings 329The p
Page 343 and 344:
24 Working with dates and timesCont
Page 345 and 346:
[ U ] 24.2 Inputting dates and time
Page 347 and 348:
[ U ] 24.2 Inputting dates and time
Page 349 and 350:
[ U ] 24.6 Converting between date
Page 351 and 352:
25 Working with categorical data an
Page 353 and 354:
[ U ] 25.1 Continuous, categorical,
Page 355 and 356:
[ U ] 25.2 Estimation with factor v
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
Page 363 and 364:
Page 365 and 366:
Page 367 and 368:
Page 369 and 370:
26 Overview of Stata estimation com
Page 371 and 372:
[ U ] 26.3 ANOVA, ANCOVA, MANOVA, a
Page 373 and 374:
[ U ] 26.5 Binary-outcome qualitati
Page 375 and 376:
[ U ] 26.9 Exact estimators 363In t
Page 377 and 378:
[ U ] 26.14 Models with time-series
Page 379 and 380:
[ U ] 26.15 Panel-data models 367xt
Page 381 and 382:
26.15.6 Random-coefficient models w
Page 383 and 384:
[ U ] 26.21 Multivariate and cluste
Page 385:
[ U ] 26.25 Reference 373should try
Page 388 and 389:
376 [ U ] 27 Commands everyone shou
Page 390 and 391:
378 [ U ] 28 Using the Internet to
Page 392 and 393:
Page 394 and 395:
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Page 402 and 403:
390 Subject and author indexcoeffic
Page 404 and 405:
392 Subject and author indexIif exp
Page 406 and 407:
394 Subject and author indexPiantad
Page 408:
396 Subject and author indexUnix,ke
show all

[U] User's Guide

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?