Multiply obverations of a variable with a vector to creat a new data set

[Sophie Nguyen]

Hi experts! I am a beginner of Stata and looking for your help. I have data set 1 or matrix 1 (63x1) with only one variable (rGDP) which has 63 observations. Here is my data set

* Example generated by -dataex-. To install: ssc install dataex
clear
input double rGDP
   .1382092096959387
 .014146426377938484
 .027488150167805852
  .02106609526097813
 .014813232383072512
  .02716049831787797
 .009517616911102122
 .009786135114663565
 .006719476339037101
 .008605657784068762
 .006978261822747705
 .003053255804518748
.0021468348244712164
.0014914328143139273
  .00410335729024301
 .006286140914971354
 .004096475569136358
  .01456329482649903
 .004192934359981258
 .012330405718094161
 .008472070469348452
.0022984456944708516
 .002247504573231376
 .007435929046440541
   .0063184194639716
 .021838158828943417
 .016896755373362535
 .008338352074226112
 .004900522755197321
 .004122216483085287
 .007053387278161984
 .013257619326913932
 .013671685931881053
  .01051969381453211
 .010339130560733777
.0053878469198497736
 .011172687222302071
.0033487765708986694
 .009318833481421417
.0029176367435669506
 .009795359897956529
 .010763470592210115
 .004187248747543143
 .011735775859328706
 .008422817008285132
  .01058803585914126
    .040633122274224
  .04662913310434898
  .04731081673511357
  .18262875323334388
  .01475801476371676
  .01233610771558253
 .006613825534999745
 .006718362155619832
 .007138671464733702
 .010811757335308453
 .012035409273322367
 .012747438017157244
 .012828445705612685
.0042635375415254525
 .007260133842266102
 .005494661062455158
 .007688537366205414
end

In addition, I have the following vector or matrix 2(1x14)
SA SB SC SD SE SF SG SH SK SL SM SN SO SP
.30229 .08977835 .0815295 .03925564 .04873896 .12323789 .11783615 .02929192 .04859169 .01511463 .12035968 .30436756 .24910508 .35174274

I want to create a new matrix (63x14) (or a data set) where each row is the result of multiplying each observation in data set 1(matrix 1) with each of elements of the above vector. I really look forward to your help. Thank you in advance and Merry Christmas!

[William Lisowski]

There are techniques that make use of Stata's matrix commands, or of the Mata subsystem, but in this case a direct approach seems more convenient.

* Example generated by -dataex-. To install: ssc install dataex
clear
input double rGDP
   .1382092096959387
 .014146426377938484
 .027488150167805852
  .02106609526097813
 .014813232383072512
  .02716049831787797
 .009517616911102122
 .009786135114663565
 .006719476339037101
 .008605657784068762
 .006978261822747705
 .003053255804518748
.0021468348244712164
.0014914328143139273
  .00410335729024301
 .006286140914971354
 .004096475569136358
  .01456329482649903
 .004192934359981258
 .012330405718094161
 .008472070469348452
.0022984456944708516
 .002247504573231376
 .007435929046440541
   .0063184194639716
 .021838158828943417
 .016896755373362535
 .008338352074226112
 .004900522755197321
 .004122216483085287
 .007053387278161984
 .013257619326913932
 .013671685931881053
  .01051969381453211
 .010339130560733777
.0053878469198497736
 .011172687222302071
.0033487765708986694
 .009318833481421417
.0029176367435669506
 .009795359897956529
 .010763470592210115
 .004187248747543143
 .011735775859328706
 .008422817008285132
  .01058803585914126
    .040633122274224
  .04662913310434898
  .04731081673511357
  .18262875323334388
  .01475801476371676
  .01233610771558253
 .006613825534999745
 .006718362155619832
 .007138671464733702
 .010811757335308453
 .012035409273322367
 .012747438017157244
 .012828445705612685
.0042635375415254525
 .007260133842266102
 .005494661062455158
 .007688537366205414
end
generate id = 1, before(rGDP)
tempfile ds1
save `ds1'

clear
input SA SB SC SD SE SF SG SH SK SL SM SN SO SP
.30229 .08977835 .0815295 .03925564 .04873896 .12323789 .11783615 .02929192 .04859169 .01511463 .12035968 .30436756 .24910508 .35174274
end
generate id = 1
tempfile ds2
save `ds2'

// do the work

use `ds1', clear
joinby id using `ds2'
drop id
foreach v of varlist SA-SP {
    replace `v' = `v'*rGDP
}
describe, short

. describe, short

Contains data
 Observations:            63                  
    Variables:            15                  
Sorted by:
     Note: Dataset has changed since last saved.

You can drop rDGP if you really want only 14 variables.

[Sophie Nguyen]

Thank you so much for your reply William Lisowski ! Really appreciate your help.

[Joro Kolev]

Here is another way how to do it. The code that is actually doing the job is in green; the rest puts the data in format you said you have the data:

clear
input SA SB SC SD SE SF SG SH SK SL SM SN SO SP
.30229 .08977835 .0815295 .03925564 .04873896 .12323789 .11783615 .02929192 .04859169 .01511463 .12035968 .30436756 .24910508 .35174274
end

mkmat SA-SP, mat(myvec)

clear

matlist myvec

input double rGDP
   .1382092096959387
 .014146426377938484
 .027488150167805852
  .02106609526097813
 .014813232383072512
  .02716049831787797
 .009517616911102122
 .009786135114663565
 .006719476339037101
 .008605657784068762
 .006978261822747705
 .003053255804518748
.0021468348244712164
.0014914328143139273
  .00410335729024301
 .006286140914971354
 .004096475569136358
  .01456329482649903
 .004192934359981258
 .012330405718094161
 .008472070469348452
.0022984456944708516
 .002247504573231376
 .007435929046440541
   .0063184194639716
 .021838158828943417
 .016896755373362535
 .008338352074226112
 .004900522755197321
 .004122216483085287
 .007053387278161984
 .013257619326913932
 .013671685931881053
  .01051969381453211
 .010339130560733777
.0053878469198497736
 .011172687222302071
.0033487765708986694
 .009318833481421417
.0029176367435669506
 .009795359897956529
 .010763470592210115
 .004187248747543143
 .011735775859328706
 .008422817008285132
  .01058803585914126
    .040633122274224
  .04662913310434898
  .04731081673511357
  .18262875323334388
  .01475801476371676
  .01233610771558253
 .006613825534999745
 .006718362155619832
 .007138671464733702
 .010811757335308453
 .012035409273322367
 .012747438017157244
 .012828445705612685
.0042635375415254525
 .007260133842266102
 .005494661062455158
 .007688537366205414
end

local mycolnames : colfullnames myvec

foreach col of local mycolnames {
    gen rGDP`col' = rGDP*myvec[1,"`col'"]
}

resulting in

. des

Contains data
 Observations:            63                  
    Variables:            15                  
--------------------------------------------------------------------------------------------------
Variable      Storage   Display    Value
    name         type    format    label      Variable label
--------------------------------------------------------------------------------------------------
rGDP            double  %10.0g                
rGDPSA          float   %9.0g                 
rGDPSB          float   %9.0g                 
rGDPSC          float   %9.0g                 
rGDPSD          float   %9.0g                 
rGDPSE          float   %9.0g                 
rGDPSF          float   %9.0g                 
rGDPSG          float   %9.0g                 
rGDPSH          float   %9.0g                 
rGDPSK          float   %9.0g                 
rGDPSL          float   %9.0g                 
rGDPSM          float   %9.0g                 
rGDPSN          float   %9.0g                 
rGDPSO          float   %9.0g                 
rGDPSP          float   %9.0g                 
--------------------------------------------------------------------------------------------------
Sorted by: 
     Note: Dataset has changed since last saved.

. summ

    Variable |        Obs        Mean    Std. dev.       Min        Max
-------------+---------------------------------------------------------
        rGDP |         63     .015873    .0282778   .0014914   .1826288
      rGDPSA |         63    .0047983    .0085481   .0004508   .0552068
      rGDPSB |         63    .0014251    .0025387   .0001339   .0163961
      rGDPSC |         63    .0012941    .0023055   .0001216   .0148896
      rGDPSD |         63    .0006231    .0011101   .0000585   .0071692
-------------+---------------------------------------------------------
      rGDPSE |         63    .0007736    .0013782   .0000727   .0089011
      rGDPSF |         63    .0019562    .0034849   .0001838   .0225068
      rGDPSG |         63    .0018704    .0033321   .0001757   .0215203
      rGDPSH |         63     .000465    .0008283   .0000437   .0053495
      rGDPSK |         63    .0007713    .0013741   .0000725   .0088742
-------------+---------------------------------------------------------
      rGDPSL |         63    .0002399    .0004274   .0000225   .0027604
      rGDPSM |         63    .0019105    .0034035   .0001795   .0219811
      rGDPSN |         63    .0048312    .0086068   .0004539   .0555863
      rGDPSO |         63     .003954    .0070441   .0003715   .0454938
      rGDPSP |         63    .0055832    .0099465   .0005246   .0642383

.

[Sophie Nguyen]

Thank you Joro Kolev!