Selection of observations in particular places and remaining have to drop

[sudharsan reddy]

Dear Statalist Users

I have a dataset that is in seconds time frame.

I have a variable 'drowsy alert (0,1)'. If it was 1, I have to select Before and after for 10 sec at the same time and select other variables (ear, mar, pitch, roll, etc.). Also, the remaining is not selected, so I must drop unselected observations.

* Example generated by -dataex-. To install: ssc install dataex
clear
input byte drowsy_alert float(ear yaw xaccel)
0 .24509516   3.152057      -69.5
0 .27469558  1.2119448        -98
0  .3374663  25.833925        -25
0 .29189208   3.933264          4
0 .30572855  -6.814655         11
0 .30815455   -7.53705         -7
0 .28909555  1.8565503      -33.5
0 .25836557 -4.1381316        -42
0  .3179895  -9.393527        -30
0 .34929505  -35.30489        -42
0 .31957665 -28.119665      -53.5
0  .3449196  -19.84711      -24.5
0  .3460014  -25.63866        1.5
0 .34284535 -28.167866       10.5
0  .3429942 -27.710104         -7
0  .3850321  -41.78772         -7
0  .4967733  -53.56257         20
0 .28017986 -25.108095        8.5
0 .54923713  -59.84064        4.5
0  .2658208  -7.032901          5
0  .3235609 -10.978204          3
0  .3237429 -22.237726         -2
0  .3152308   2.507217       -2.5
0  .3211721  -.7686391         12
0  .3010013  -10.68632       15.5
0 .38973865 -35.016666         21
0  .2938491 -1.1214831        -.5
0  .5797473  37.066643       -9.5
0  .3065653   11.93144       19.5
0 .28339198   .8973703       15.5
0     .3138   4.916839       -9.5
0  .3333143   6.941586          5
0  .2847283   2.767074        8.5
0 .27515548  .22238716      -14.5
0  .3152577 -19.071331      -20.5
0 .28896973  -8.834283       -8.5
0  .3198381   6.693551       -4.5
0  .3141518   6.950264        -13
0  .3227474   2.893987        -20
0  .3279735   7.333499        -23
0  .3572677  10.233822       -8.5
0  .3341861  1.7056438         13
0  .3246058 -1.7007967       15.5
0  .3281207   5.667296       14.5
0  .3284779    5.87743      -14.5
0   .333318 -30.523764        -17
0 .29194772  2.3578784         -3
0 .26822582   5.888083          1
0  .2997589  -.6680353         34
0 .31093675  -.4539446         35
0  .3139052 -2.1117644       14.5
0  .3381171  21.620403       -1.5
0 .30692345  2.0488026         -6
0  .3157998  1.1478596         -4
0  .3195391   3.790605       19.5
0  .3195186 -1.7708135         46
0  .3047022 -1.3647008         49
0  .3134151  2.9115145       43.5
0  .3146598  -1.215125      -22.5
0  .3273014 -.17594737        -46
0   .333936  4.4230275        -20
0  .3358562   7.483302       -2.5
0  .3202161   8.076697        -41
0  .3369985  1.6177557      -35.5
0  .3235722   1.571387       21.5
0  .3323976  3.2013786      -22.5
0  .3212108  2.6737854        -34
0 .32083625   4.618731        -21
0  .3096248  4.7360425        -40
0  .3125585   5.757248      -35.5
0  .3684984   20.92667        -20
0 .25187486   2.594518        -13
0 .29651463  -3.403251      -18.5
0 .28928933   -4.59172        -27
0  .3057461   .3851113      -24.5
0   .294055   .4082312        -22
0  .3068546   4.027759      -17.5
0  .3806376  18.512487      -31.5
0  .3363083  18.514334      -42.5
0 .28818095   3.694802        -22
0  .2805385  -3.633008         -5
0 .24583346  -2.114474         -4
0  .3116878  -3.728134         -4
0  .3203255 -10.032502          2
0  .3202574  -7.427155        2.5
0 .27444783  .56667036         13
0  .3390788    3.41355       21.5
0  .3167669  -2.832474        -11
0  .2897667  2.5012996      -28.5
0  .3517807   32.91333       14.5
0  .3229712   8.485733       47.5
0  .3240312 -1.7506478         11
0   .309429  1.6615542        -45
0  .3297229  1.0837443      -29.5
0 .33110955   -3.78611      -36.5
0  .3082924 -4.4370394      -64.5
0  .3231585   .2519378         -4
0  .3230212 -1.5858033       26.5
0  .3497593  12.913444         14
0  .3686738  18.924744         19
0  .3187912 -2.3514044       17.5
0 .33167645  .42391065         21
0  .3118064  -.8982189         -4
0 .29571563 -2.1299684        -32
0  .3078536   4.813024      -36.5
0  .3237729  2.2446868         .5
0 .27396017  .40544525         36
0  .3089221  .40400165       31.5
0  .3190183    4.92683        2.5
0  .3268133   7.567719       39.5
0  .3227265   7.775603         70
0 .33367175  22.693327       56.5
0 .28984547  4.0385175       45.5
0 .32151735 -2.2195983          5
0 .28535485    2.05215        -51
0  .3101388   4.615924        -29
0   .305243  -2.932359         83
0 .31429815   2.885223         83
0 .33610585   1.574701         29
0  .3336555   9.740571       24.5
0  .3070499   3.755085         68
0  .3141804  1.1230565         19
0 .31511045 -1.8161874        -26
0   .310896  1.9267104       -9.5
0 .27502215 -18.365107         36
0  .2811845  .23909763         20
0 .29561743  1.8720448        -42
0   .372529  22.262154         18
0  .3246833  13.471842         27
0   .329046  3.2682354         .5
0 .28300127   .3360842        -12
0 .27465257   .8226157        4.5
0 .28079486    3.28851       21.5
0  .3264113   7.321476        -19
0  .3353012   9.007659        -12
0  .3137377   .6515442      -10.5
0  .3243925 -1.7825148       -5.5
0  .3268679  .29458478         19
0  .3154554  -2.470754       13.5
0  .3432423  -27.84503        6.5
0  .2763726  1.9735255       -2.5
0 .34797195  20.999287         -7
0  .3132618    14.9116         -3
0  .3111454    3.38122      -17.5
0  .3423311  19.702274      -53.5
0  .3048555   5.097943        -36
0   .333991    6.47181         14
0  .3473473  -1.394583       28.5
0  .3341567  2.6444004  11.666667
0  .3163672   .8580667          9
0  .3193482  1.7050272        -10
0  .3302314  19.365936        -14
0  .3140057   5.483074      -10.5
0  .3278223   5.814243      -27.5
0 .27773166  .05762342         -9
0 .32400155   1.256113          0
0  .3345667 -1.4042766         44
0 .32224935   1.928596       90.5
0   .355525  13.127116  73.666664
0         .          .        -20
0  .2963615 -13.067057          4
0  .3214451   5.648023       -1.5
0 .31966275 -1.7812462        -13
0  .3300926  -2.526831         25
0  .3280093  1.8690643       16.5
0  .3235738  -3.069725        7.5
0   .317889  -11.87165       29.5
0  .3228918 -28.260197         58
0  .3207029  -1.001849   52.33333
0         .          .         -5
0  .3281686 -1.0958292         -3
0  .3058914 -.27009198        7.5
0  .3086183  -3.940522        3.5
0  .3044779  -4.784016         20
0  .2908267 -4.6923175         24
0 .29414514  -19.31266        -26
0  .3106948  4.5830045         -9
0  .3506775   20.90667          8
0  .3070657  3.1424766          7
0  .3177391    6.27119        -29
0   .490491   37.56418      -59.5
0  .3064015  4.2244325        -28
0  .3090135  -12.64906       14.5
0   .257633  12.362074       29.5
0 .27017805   10.04469        -.5
0 .28569728  -9.722733      -12.5
0  .3185834  3.5561354       -5.5
0  .3121328   6.958697          2
0 .31301335  1.7432005       -1.5
0  .3183599  -2.438792       12.5
0  .3158318 -2.0888247       30.5
0  .3017195 -1.0291058       42.5
0  .3178915  3.9340084         23
0  .3096377  3.6222625       16.5
0 .28379282  -3.516985         46
0  .3202912   .7373317       34.5
0 .27091503   5.669868        2.5
0  .4070185  24.624575      -13.5
0  .4534674   30.89569         -1
0  .2540866   2.595747         17
0  .3207505   3.308932       11.5
0   .303217 -3.6389556       -7.5
0  .3128869  -1.135703       -5.5
0  .3244446   3.906522       37.5
0   .316616  2.6679666       64.5
0  .3147413  1.9930302         38
0  .3185397  2.4983644        1.5
0 .31924045  -.4361427        6.5
0 .28114998   1.668376  -5.333333
0  .3066825  -.8698444        -61
0  .3535487   9.473306        -17
0  .3522604  26.662487       15.5
0  .3060398   2.904725        3.5
0  .3000486   6.307335      -12.5
0  .3240341  -6.041346      -16.5
0 .33496895    .160001         .5
0  .3273665   2.818993         -2
0   .320201   2.646148       -8.5
0  .3350128  12.437415        -.5
0  .3828649  27.400364         21
0  .3227399 -21.353104         37
0 .24557747  -4.652559       15.5
0 .29256988   2.817939          2
0  .3408765  -.5292292      -10.5
0  .3269546   .4611909      -22.5
0  .3461553  -.5901774          7
0 .34565085  4.5269437          8
0   .345953  17.859135        -26
0 .26311556   5.206263      -35.5
0  .2802696  -2.571793        -16
0  .3030011  2.3352718       25.5
0  .3280605  13.014326        3.5
0 .34677115  11.998735        -31
0  .3232398   9.683682        1.5
0  .3371925   8.099224         14
0  .3116401   6.834691      -19.5
0 .33263925   6.236697      -14.5
0   .376877  24.415014         -1
0 .32150635    7.90935       -4.5
0  .3245496  -.9484375       -6.5
0  .3295105     .95607        -16
0  .3211924   .7394135       14.5
0  .3246507   .8619643         26
0  .3391406  -.3895059         11
0 .29830745 -2.0086534        -38
0  .3261681  -2.427262      -42.5
0  .3397923   .9285861         -9
0  .3475226   2.127618       -6.5
0  .3406994   2.626915       22.5
0  .3499253  3.4300506       25.5
0  .3276749  17.487896        5.5
0  .3219466  1.4448615        -14
0  .3379673   2.122857      -31.5
0  .3190696   2.427997      -16.5
0  .3644548  14.171706      -21.5
0 .29524794   12.36485        -39
0  .3231249   .8600168      -39.5
0  .3350129   9.593235       -7.5
0  .3232964   2.897984        -37
0  .3147587   6.407427      -43.5
0   .312732  .04722637         14
0  .3112856  -5.588071      -18.5
0  .3070466  -4.588846      -36.5
0  .3270115  -1.798376        -19
0 .32987195   .9121557       -5.5
0  .3459505   2.632721       12.5
0   .332687  1.7638216         15
0  .3265101 -18.242613          6
0  .2974124  -6.225534        5.5
0  .3378132  -1.552393       18.5
0  .3452167  -1.810625         16
0 .33946756 -1.2950093         17
0  .3210673  -.9824939         11
0  .3101346 -2.1690621          4
0  .3356368  -.7488473       25.5
0 .34378785  -2.002936          2
0  .3324859  -4.161588          3
0  .3036562  -23.77189       23.5
0  .3418611 -1.6607273       19.5
0  .3333932  4.3101835          2
0  .3168517  -8.483593          5
0  .3201797 -22.724215       16.5
0  .3594939  3.7092466         -3
0  .3364767   7.771438        5.5
0  .3814755  21.581394       22.5
0  .3162334  10.322723       34.5
0  .3319066 -1.0410401       33.5
0   .324233  1.7317387       17.5
0 .32574055  -.5201638         -3
0  .3298243   1.447046         -4
0  .3180909  11.259713          2
0  .3289174    5.33922          4
0 .32217205   3.573083       24.5
0  .3362865   2.638008         21
0   .330873   5.663885         24
0  .3611638   9.367471        6.5
0  .3394503   .7708265      -17.5
0   .309599  3.5962386        -.5
0  .3389986 -1.0320557          5
0  .3442231  -.8506008         -2
0  .3440611   6.002852      -53.5
0  .3626506   9.801284      -65.5
0  .4128975    29.1558        -12
0  .3535806  17.780037       13.5
0  .3168236  -.4812829       33.5
0  .3351442 -1.5218894         40
0 .33791825   7.877331         31
0   .359647   5.407533         59
0  .3413583  4.2814445       52.5
0  .3531284  2.3038764         22
0  .3122402  1.8686392         -1
0  .3362742   7.774037        -48
0  .3193007   4.298915       -6.5
0 .28509814   4.038304         23
0  .3693259   29.26923        -31
0   .313516    10.7661        -55
0  .3463204   6.947022        -30
0  .3455834   3.680147       -3.5
0  .3194572   3.578139         16
0  .3423015   6.050139         58
0   .354807    3.21263         59
0  .3613737   5.034236      -15.5
0  .3061411    4.06236      -39.5
0  .3299903  4.2683086          4
0  .3550066   7.221128       -8.5
0  .3503798  14.118205      -22.5
0  .4216912  32.684345         20
0  .3185185  10.096978       52.5
0   .384413   24.50892       49.5
0  .3105037   13.74513       13.5
0  .3538532  17.901268        -36
0  .3070789   11.57658      -52.5
0  .3248033 -.17371657        -43
0 .30832535  3.7054856         .5
0  .3443392   6.727169       33.5
0  .3759349   6.890261          5
0  .3484051  18.050465      -21.5
0 .29277322 -1.0006353        -36
0   .340279   8.369083      -12.5
0 .41134095  29.833616        7.5
0  .3365236 -.10328598      -15.5
0  .3443129  -.4568615          2
0 .31981745  1.2194258        3.5
0  .3488359   3.086784      -20.5
0  .3346641 -2.1380453        -11
0  .3270417   6.496648        8.5
0  .2851185   8.477276      -12.5
0  .3126919   4.469355         -7
0  .3160588  -2.234615       54.5
0  .3307915 -1.6896495       49.5
0  .3330847   1.810255      -17.5
0  .3370638 -1.6081933        -32
0  .3404683  -3.117255        -29
0  .3359232 -2.4413574        -16
0  .3385114  -.8715399         28
0  .3385126  -.9605815       31.5
0  .3182455   3.571456        9.5
0   .344857   3.413137        -49
0  .3275326  -.4624797        -38
0  .3357616  1.5332956       21.5
0  .3023182   5.413653         -2
0   .338812   4.623074       -1.5
0  .3623784   25.10291         30
0 .29635966  2.1494136         11
0  .3088952  1.3211702        -33
0  .3043729  4.5450525        -56
0  .3139496   6.245492        -16
0 .29605022  4.6195846       35.5
0  .3291956   1.301001         51
0  .3415569  .50640893         33
0 .29390115   2.782265         15
0 .29333186   2.480448         13
0 .27155346 -17.861692        5.5
0  .3187867  4.3996143       33.5
0   .332439  1.1721709       32.5
0  .3362162   5.061625        2.5
0  .3834129  23.158596        3.5
0 .29508716   5.266411   5.333333
0 .28633025  4.7072215         16
0   .303799   5.190825       14.5
0  .3058285  1.7231766        -29
0  .3263481   6.232832        -17
0  .3357759  1.2982093         -4
0  .3176449   2.191399        -17
0   .321653  3.2613666          3
0 .26637548   5.020848         27
0  .3183152   1.897319       33.5
0  .3117174  3.2033224         20
0  .3339114   7.088317  10.666667
0  .3358385   7.346503         11
0  .3343911   .5719134          0
0  .3238701 -.03826208        -14
0  .3326226  .03494594       -6.5
0  .3173294  -4.272373       -5.5
0  .3518851  9.1593895      -18.5
0 .29147732   7.688195        7.5
0 .29711652 -2.1328719         15
0 .29376414  -3.997328       -6.5
0 .31017315  -2.530146        -14
0 .29667348 .013496224      -21.5
0   .312354   2.905972       -3.5
0  .3553312   4.026645         22
0  .3072327  3.0405445         23
0  .3433628  1.2787746         -3
0     .3009    8.32305      -17.5
0  .3500584   4.966589       -4.5
0  .3262477 -1.7588094        9.5
0   .327539  11.598727        3.5
0  .3413142  20.391485 -2.3333333
0 .25290722   9.679523        -45
0  .3158843   6.104727      -28.5
0   .323854   .9614771      -33.5
0  .3181352  1.8110483      -49.5
0  .3232111   6.623262        -92
0   .321865   4.255182        -39
0  .3203425   .6083523         10
0 .28474358   5.300296      -49.5
0 .28467306  -.4150833        -33
0  .3260178  -2.814348        2.5
0  .3323572  -2.553589         30
0  .3390335   2.907475         33
0  .3410193   2.557641       36.5
0  .3193263  -9.649957         58
0  .2894206  -2.606306       33.5
0  .3298174    7.38765       22.5
0  .3678729   5.146026       12.5
0  .3449356   7.942436      -22.5
0  .3244812   7.630728      -48.5
0  .3289764   6.527968      -33.5
0  .3496153  26.280624         -3
0  .3391147  -.3299958       15.5
0 .33474085  1.7301993         76
0 .35127795  -.4598611         95
0  .2817827  -16.68769         57
0  .3414509   8.376446       24.5
0 .38443205   21.99963         11
0   .312306  -6.979867         11
0  .3059695  -9.924537        -24
0  .3277621  -2.546688        -44
0  .3161177  -2.426929         17
0  .3105725  -5.185435       50.5
0  .3156092  -.5547887       17.5
0  .2613951  -9.590036      -10.5
0  .3165033 -17.653515        -19
0 .29795387 -16.989618        -15
0  .3060696 -23.592636          7
0  .3625115 -32.068645       40.5
0 .27055097  -10.56523       46.5
0  .3476346  -32.38566        6.5
0  .3132421  3.1157546         20
0  .3627895   21.90852       37.5
0  .3329839 -18.446358        5.5
0  .3512829  -31.77985         27
0   .258596    -5.9207         38
0 .29160702  -20.23495       -7.5
0  .3255904  -2.729274        -24
0  .3300003 -24.669744        7.5
0 .34937724  -33.74503       37.5
0  .3002142  -6.041892       29.5
0   .368622  -36.61375       15.5
0 .27316707 -10.094765       17.5
0  .3050689   7.139463       16.5
0  .3252147   6.531385       -5.5
0  .3295933  1.9692322        -15
0  .3418319  2.2533364        6.5
0  .3390009   2.077197         14
0  .3016262 -4.3343487          4
0  .3597531   8.853257       -9.5
0  .3505317   10.23838      -27.5
0  .4541542  35.510212        -16
0  .3236194   2.970876        7.5
0    .32011   2.533516          2
0 .29232416  2.9654446         18
0   .253638 -.41300794       16.5
0  .3112704  1.4208935       -1.5
0 .27626485 -2.0456066        8.5
0  .2874661   .7249337        1.5
0   .290599  -2.956958          7
0  .3202863  -3.807026       15.5
0  .3038951   5.488745          3
0  .3670783   24.19972          0
0  .3330495  1.9156926         -4
0 .33919245 -.52032727          6
0  .2916362   .2709075         26
0 .25956586 -.19939883         24
0 .27218378 -2.2239954      -12.5
0 .26007423   -3.40049      -22.5
0   .269402   1.435545      -17.5
0  .3035928  -.3114296        -17
0  .3211926  -.9254498        3.5
0  .3170742 -1.8693157         -2
0  .3445951  1.3891385        -12
0  .3045087 -1.5147052        -28
0   .329155  1.7897017      -40.5
0  .2556418   3.249992       30.5
0  .3075093   .6451341       11.5
0  .3327344  23.198597      -21.5
0  .2966618 -1.9860697       27.5
0 .28057545  -5.493829        1.5
0  .2942331  -4.629362         15
end

[Clyde Schechter]

Your question is not entirely clear, and your data example does not include any observations with drowsy_alert = 1, nor is there any time variable.

Would I be correct in understanding that the observations in the data set are in correct chronological order and that each observation was taken 1 second after the one above it? And you want to keep those observations that are within 10 seconds before or after the ones where drowsy_alert == 1? If so:

gen `c(obs_t)' seconds = _n
rangestat (sum) drowsy_alert, interval(seconds -10 10)
keep if drowsy_alert_sum
drop drowsy_alert_sum

-rangestat- is written by Robert Picard, Nick Cox, and Roberto Ferrer. It is available from SSC.