create a dual table

Create a dual table as follows:

CREATE TABLE dual (
  dummy int
);
INSERT INTO TABLE dual SELECT count(*)+1 FROM dual;

Sparse dataset generation by a single task

create table regression_data1
as
select lr_datagen('-n_examples 10k -n_features 10 -seed 100') as (label,features)
from dual;

Find the details of the option, run lr_datagen('-help').

You can generate a sparse dataset as well as a dense dataset. By the default, a sparse dataset is generated.

hive> desc regression_data1;
OK
label                   float                   None
features                array<string>           None

hive> select * from regression_data1 limit 2;
OK
0.7220096       ["140:2.8347101","165:3.0056276","179:4.030076","112:3.3919246","99:3.98914","16:3.5653272","128:3.046535","124:2.7708225","78:2.4960368","6:1.7866131"]
0.7346627       ["139:1.9607254","110:2.958568","186:3.2524762","31:3.9243593","167:0.72854257","26:1.8355447","117:2.7663715","3:2.1551287","179:3.1099443","19:3.6411424"]
Time taken: 0.046 seconds, Fetched: 2 row(s)

Classification dataset generation

You can use "-cl" option to generation 0/1 label.

select lr_datagen("-cl") as (label,features)
from dual 
limit 5;
OK
1.0     ["84:3.4227803","80:3.8875976","58:3.2909582","123:3.1056073","194:3.3360343","199:2.20207","75:3.5469763","74:3.3869767","126:0.9969454","93:2.5352612"]
0.0     ["84:-0.5568947","10:0.621897","6:-0.13126314","190:0.18610542","131:1.7232913","24:-2.7551131","113:-0.9842969","177:0.062993184","176:-0.19020283","21:-0.54811275"]
1.0     ["73:3.4391513","198:4.42387","164:4.248151","66:3.5224934","84:1.9026604","76:0.79803777","18:2.2168183","163:2.248695","119:1.5906067","72:2.0267224"]
1.0     ["34:2.9269936","35:0.37033868","39:3.771989","47:2.2087111","28:2.9445739","55:4.134555","14:2.4297745","164:3.0913055","52:2.0519433","128:2.9108515"]
1.0     ["98:4.2451696","4:3.486905","133:2.4589922","26:2.7301126","103:2.6827147","2:3.6198254","34:3.7042716","47:2.5515237","68:2.4294896","197:4.4958663"]

Dense dataset generation

create table regression_data_dense
as
select lr_datagen("-dense -n_examples 9999 -n_features 100 -n_dims 100") as (label,features)
from dual;

hive> desc regression_data_dense;
OK
label                   float                   None
features                array<float>            None

hive> select * from regression_data_dense limit 1;
OK
0.7274741       [4.061373,3.9373128,3.5195694,3.3604698,3.7698417,4.2518,3.8796813,1.6020582,4.937072,1.5513933,3.0289552,2.6674519,3.432688,2.980945,1.8897587,2.9770515,3.3435504,1.7867403,3.4057906,1.2151588,5.0587463,2.1410913,2.8097973,2.4518871,3.175268,3.3347685,3.728993,3.1443396,3.5506077,3.6357877,4.248151,3.5224934,3.2423255,2.5188355,1.8626233,2.8432152,2.2762651,4.57472,2.2168183,2.248695,3.3636255,2.8359523,2.0327945,1.5917025,2.9269936,0.37033868,2.6151125,4.545956,2.0863252,3.7857852,2.9445739,4.134555,3.0660007,3.4279037,2.0519433,2.9108515,3.5171766,3.4708095,3.161707,2.39229,2.4589922,2.7301126,3.5303073,2.7398396,3.7042716,2.5515237,3.0943663,0.41565156,4.672767,3.1461313,3.0443575,3.4023938,2.2205734,1.8950733,2.1664586,4.8654623,2.787029,4.0460386,2.4455893,3.464298,1.062505,3.0513604,4.382525,2.771433,3.2828436,3.803544,2.178681,4.2466116,3.5440445,3.1546876,3.4248536,0.9067459,3.0134914,1.9528451,1.7175893,2.7029774,2.5759792,3.643847,3.0799,3.735559]
Time taken: 0.044 seconds, Fetched: 1 row(s)

Parallel and scalable data generation using multiple reducers (RECOMMENDED)

Dataset generation using (at max) 10 reducers.

set hivevar:n_parallel_datagen=10;

create or replace view seq10 
as
select * from (
  select generate_series(1,${n_parallel_datagen})
  from dual 
) t
DISTRIBUTE BY value;

set mapred.reduce.tasks=${n_parallel_datagen};
create table lrdata1k
as
select lr_datagen("-n_examples 100")
from seq10;
set mapred.reduce.tasks=-1; -- reset to the default setting

hive> select count(1) from lrdata1k;
OK
1000