vastorbit.VastFrame.sample

VastFrame.sample(n: Annotated[int | float | Decimal, 'Python Numbers'] | None = None, x: float | None = None, method: Literal['random', 'systematic', 'stratified'] = 'random', by: Annotated[str | list[str], 'STRING representing one column or a list of columns'] | None = None) → VastFrame

Downsamples the input VastFrame.

Warning

The result might be inconsistent between attempts at SQL code generation if the data is not ordered.

Parameters:

• n (PythonNumber, optional) – Approximate number of elements to consider in the sample.

• x (float, optional) – The sample size. For example, if set to 0.33, it downsamples to approximatively 33% of the relation.

• method (str, optional) –

  The Sample method.

  • random:

    Random Sampling.

  • systematic:

    Systematic Sampling.

  • stratified:

    Stratified Sampling.

• by (SQLColumns, optional) – VastColumns used in the partition.

Returns:

sample VastFrame

Return type:

VastFrame

Examples

We import vastorbit:

import vastorbit as vo

Hint

By assigning an alias to vastorbit, we mitigate the risk of code collisions with other libraries. This precaution is necessary because vastorbit uses commonly known function names like “average” and “median”, which can potentially lead to naming conflicts. The use of an alias ensures that the functions from vastorbit are used as intended without interfering with functions from other libraries.

For this example, we will use the Titanic dataset:

from vastorbit.datasets import load_titanic

vdf = load_titanic()

	123 pclass Integer	123 survived Integer	Abc name Varchar(164)	Abc sex Varchar(20)	123 age Double	123 sibsp Integer	123 parch Integer	Abc ticket Varchar(36)	123 fare Double	Abc cabin Varchar(30)	Abc embarked Varchar(20)	Abc boat Varchar(100)	123 body Integer	Abc home.dest Varchar(100)
1	3	1	McCormack, Mr. Thomas Joseph	male	[null]	0	0	367228	7.75	[null]	Q	[null]	[null]	[null]
2	3	1	McCoy, Miss. Agnes	female	[null]	2	0	367226	23.25	[null]	Q	16	[null]	[null]
3	3	1	McCoy, Miss. Alicia	female	[null]	2	0	367226	23.25	[null]	Q	16	[null]	[null]
4	3	1	McCoy, Mr. Bernard	male	[null]	2	0	367226	23.25	[null]	Q	16	[null]	[null]
5	3	1	McDermott, Miss. Brigdet Delia	female	[null]	0	0	330932	7.7875	[null]	Q	13	[null]	[null]
6	3	0	McEvoy, Mr. Michael	male	[null]	0	0	36568	15.5	[null]	Q	[null]	[null]	[null]
7	3	1	McGovern, Miss. Mary	female	[null]	0	0	330931	7.8792	[null]	Q	13	[null]	[null]
8	3	1	McGowan, Miss. Anna "Annie"	female	15.0	0	0	330923	8.0292	[null]	Q	[null]	[null]	[null]
9	3	0	McGowan, Miss. Katherine	female	35.0	0	0	9232	7.75	[null]	Q	[null]	[null]	[null]
10	3	0	McMahon, Mr. Martin	male	[null]	0	0	370372	7.75	[null]	Q	[null]	[null]	[null]
11	3	0	McNamee, Mr. Neal	male	24.0	1	0	376566	16.1	[null]	S	[null]	[null]	[null]
12	3	0	McNamee, Mrs. Neal (Eileen O'Leary)	female	19.0	1	0	376566	16.1	[null]	S	[null]	53	[null]
13	3	0	McNeill, Miss. Bridget	female	[null]	0	0	370368	7.75	[null]	Q	[null]	[null]	[null]
14	3	0	Meanwell, Miss. (Marion Ogden)	female	[null]	0	0	SOTON/O.Q. 392087	8.05	[null]	S	[null]	[null]	[null]
15	3	0	Meek, Mrs. Thomas (Annie Louise Rowley)	female	[null]	0	0	343095	8.05	[null]	S	[null]	[null]	[null]
16	3	0	Meo, Mr. Alfonzo	male	55.5	0	0	A.5. 11206	8.05	[null]	S	[null]	201	[null]
17	3	0	Mernagh, Mr. Robert	male	[null]	0	0	368703	7.75	[null]	Q	[null]	[null]	[null]
18	3	1	Midtsjo, Mr. Karl Albert	male	21.0	0	0	345501	7.775	[null]	S	15	[null]	[null]
19	3	0	Miles, Mr. Frank	male	[null]	0	0	359306	8.05	[null]	S	[null]	[null]	[null]
20	3	0	Mineff, Mr. Ivan	male	24.0	0	0	349233	7.8958	[null]	S	[null]	[null]	[null]
21	3	0	Minkoff, Mr. Lazar	male	21.0	0	0	349211	7.8958	[null]	S	[null]	[null]	[null]
22	3	0	Mionoff, Mr. Stoytcho	male	28.0	0	0	349207	7.8958	[null]	S	[null]	[null]	[null]
23	3	0	Mitkoff, Mr. Mito	male	[null]	0	0	349221	7.8958	[null]	S	[null]	[null]	[null]
24	3	1	Mockler, Miss. Helen Mary "Ellie"	female	[null]	0	0	330980	7.8792	[null]	Q	16	[null]	[null]
25	3	0	Moen, Mr. Sigurd Hansen	male	25.0	0	0	348123	7.65	F G73	S	[null]	309	[null]
26	3	1	Moor, Master. Meier	male	6.0	0	1	392096	12.475	E121	S	14	[null]	[null]
27	3	1	Moor, Mrs. (Beila)	female	27.0	0	1	392096	12.475	E121	S	14	[null]	[null]
28	3	0	Moore, Mr. Leonard Charles	male	[null]	0	0	A4. 54510	8.05	[null]	S	[null]	[null]	[null]
29	3	1	Moran, Miss. Bertha	female	[null]	1	0	371110	24.15	[null]	Q	16	[null]	[null]
30	3	0	Moran, Mr. Daniel J	male	[null]	1	0	371110	24.15	[null]	Q	[null]	[null]	[null]
31	3	0	Moran, Mr. James	male	[null]	0	0	330877	8.4583	[null]	Q	[null]	[null]	[null]
32	3	0	Morley, Mr. William	male	34.0	0	0	364506	8.05	[null]	S	[null]	[null]	[null]
33	3	0	Morrow, Mr. Thomas Rowan	male	[null]	0	0	372622	7.75	[null]	Q	[null]	[null]	[null]
34	3	1	Moss, Mr. Albert Johan	male	[null]	0	0	312991	7.775	[null]	S	B	[null]	[null]
35	3	1	Moubarek, Master. Gerios	male	[null]	1	1	2661	15.2458	[null]	C	C	[null]	[null]
36	3	1	Moubarek, Master. Halim Gonios ("William George")	male	[null]	1	1	2661	15.2458	[null]	C	C	[null]	[null]
37	3	1	Moubarek, Mrs. George (Omine "Amenia" Alexander)	female	[null]	0	2	2661	15.2458	[null]	C	C	[null]	[null]
38	3	1	Moussa, Mrs. (Mantoura Boulos)	female	[null]	0	0	2626	7.2292	[null]	C	[null]	[null]	[null]
39	3	0	Moutal, Mr. Rahamin Haim	male	[null]	0	0	374746	8.05	[null]	S	[null]	[null]	[null]
40	3	1	Mullens, Miss. Katherine "Katie"	female	[null]	0	0	35852	7.7333	[null]	Q	16	[null]	[null]
41	3	1	Mulvihill, Miss. Bertha E	female	24.0	0	0	382653	7.75	[null]	Q	15	[null]	[null]
42	3	0	Murdlin, Mr. Joseph	male	[null]	0	0	A./5. 3235	8.05	[null]	S	[null]	[null]	[null]
43	3	1	Murphy, Miss. Katherine "Kate"	female	[null]	1	0	367230	15.5	[null]	Q	16	[null]	[null]
44	3	1	Murphy, Miss. Margaret Jane	female	[null]	1	0	367230	15.5	[null]	Q	16	[null]	[null]
45	3	1	Murphy, Miss. Nora	female	[null]	0	0	36568	15.5	[null]	Q	16	[null]	[null]
46	3	0	Myhrman, Mr. Pehr Fabian Oliver Malkolm	male	18.0	0	0	347078	7.75	[null]	S	[null]	[null]	[null]
47	3	0	Naidenoff, Mr. Penko	male	22.0	0	0	349206	7.8958	[null]	S	[null]	[null]	[null]
48	3	1	Najib, Miss. Adele Kiamie "Jane"	female	15.0	0	0	2667	7.225	[null]	C	C	[null]	[null]
49	3	1	Nakid, Miss. Maria ("Mary")	female	1.0	0	2	2653	15.7417	[null]	C	C	[null]	[null]
50	3	1	Nakid, Mr. Sahid	male	20.0	1	1	2653	15.7417	[null]	C	C	[null]	[null]
51	3	1	Nakid, Mrs. Said (Waika "Mary" Mowad)	female	19.0	1	1	2653	15.7417	[null]	C	C	[null]	[null]
52	3	0	Nancarrow, Mr. William Henry	male	33.0	0	0	A./5. 3338	8.05	[null]	S	[null]	[null]	[null]
53	3	0	Nankoff, Mr. Minko	male	[null]	0	0	349218	7.8958	[null]	S	[null]	[null]	[null]
54	3	0	Nasr, Mr. Mustafa	male	[null]	0	0	2652	7.2292	[null]	C	[null]	[null]	[null]
55	3	0	Naughton, Miss. Hannah	female	[null]	0	0	365237	7.75	[null]	Q	[null]	[null]	[null]
56	3	0	Nenkoff, Mr. Christo	male	[null]	0	0	349234	7.8958	[null]	S	[null]	[null]	[null]
57	3	1	Nicola-Yarred, Master. Elias	male	12.0	1	0	2651	11.2417	[null]	C	C	[null]	[null]
58	3	1	Nicola-Yarred, Miss. Jamila	female	14.0	1	0	2651	11.2417	[null]	C	C	[null]	[null]
59	3	0	Nieminen, Miss. Manta Josefina	female	29.0	0	0	3101297	7.925	[null]	S	[null]	[null]	[null]
60	3	0	Niklasson, Mr. Samuel	male	28.0	0	0	363611	8.05	[null]	S	[null]	[null]	[null]
61	3	1	Nilsson, Miss. Berta Olivia	female	18.0	0	0	347066	7.775	[null]	S	D	[null]	[null]
62	3	1	Nilsson, Miss. Helmina Josefina	female	26.0	0	0	347470	7.8542	[null]	S	13	[null]	[null]
63	3	0	Nilsson, Mr. August Ferdinand	male	21.0	0	0	350410	7.8542	[null]	S	[null]	[null]	[null]
64	3	0	Nirva, Mr. Iisakki Antino Aijo	male	41.0	0	0	SOTON/O2 3101272	7.125	[null]	S	[null]	[null]	Finland Sudbury, ON
65	3	1	Niskanen, Mr. Juha	male	39.0	0	0	STON/O 2. 3101289	7.925	[null]	S	9	[null]	[null]
66	3	0	Nosworthy, Mr. Richard Cater	male	21.0	0	0	A/4. 39886	7.8	[null]	S	[null]	[null]	[null]
67	3	0	Novel, Mr. Mansouer	male	28.5	0	0	2697	7.2292	[null]	C	[null]	181	[null]
68	3	1	Nysten, Miss. Anna Sofia	female	22.0	0	0	347081	7.75	[null]	S	13	[null]	[null]
69	3	0	Nysveen, Mr. Johan Hansen	male	61.0	0	0	345364	6.2375	[null]	S	[null]	[null]	[null]
70	3	0	O'Brien, Mr. Thomas	male	[null]	1	0	370365	15.5	[null]	Q	[null]	[null]	[null]
71	3	0	O'Brien, Mr. Timothy	male	[null]	0	0	330979	7.8292	[null]	Q	[null]	[null]	[null]
72	3	1	O'Brien, Mrs. Thomas (Johanna "Hannah" Godfrey)	female	[null]	1	0	370365	15.5	[null]	Q	[null]	[null]	[null]
73	3	0	O'Connell, Mr. Patrick D	male	[null]	0	0	334912	7.7333	[null]	Q	[null]	[null]	[null]
74	3	0	O'Connor, Mr. Maurice	male	[null]	0	0	371060	7.75	[null]	Q	[null]	[null]	[null]
75	3	0	O'Connor, Mr. Patrick	male	[null]	0	0	366713	7.75	[null]	Q	[null]	[null]	[null]
76	3	0	Odahl, Mr. Nils Martin	male	23.0	0	0	7267	9.225	[null]	S	[null]	[null]	[null]
77	3	0	O'Donoghue, Ms. Bridget	female	[null]	0	0	364856	7.75	[null]	Q	[null]	[null]	[null]
78	3	1	O'Driscoll, Miss. Bridget	female	[null]	0	0	14311	7.75	[null]	Q	D	[null]	[null]
79	3	1	O'Dwyer, Miss. Ellen "Nellie"	female	[null]	0	0	330959	7.8792	[null]	Q	[null]	[null]	[null]
80	3	1	Ohman, Miss. Velin	female	22.0	0	0	347085	7.775	[null]	S	C	[null]	[null]
81	3	1	O'Keefe, Mr. Patrick	male	[null]	0	0	368402	7.75	[null]	Q	B	[null]	[null]
82	3	1	O'Leary, Miss. Hanora "Norah"	female	[null]	0	0	330919	7.8292	[null]	Q	13	[null]	[null]
83	3	1	Olsen, Master. Artur Karl	male	9.0	0	1	C 17368	3.1708	[null]	S	13	[null]	[null]
84	3	0	Olsen, Mr. Henry Margido	male	28.0	0	0	C 4001	22.525	[null]	S	[null]	173	[null]
85	3	0	Olsen, Mr. Karl Siegwart Andreas	male	42.0	0	1	4579	8.4042	[null]	S	[null]	[null]	[null]
86	3	0	Olsen, Mr. Ole Martin	male	[null]	0	0	Fa 265302	7.3125	[null]	S	[null]	[null]	[null]
87	3	0	Olsson, Miss. Elina	female	31.0	0	0	350407	7.8542	[null]	S	[null]	[null]	[null]
88	3	0	Olsson, Mr. Nils Johan Goransson	male	28.0	0	0	347464	7.8542	[null]	S	[null]	[null]	[null]
89	3	1	Olsson, Mr. Oscar Wilhelm	male	32.0	0	0	347079	7.775	[null]	S	A	[null]	[null]
90	3	0	Olsvigen, Mr. Thor Anderson	male	20.0	0	0	6563	9.225	[null]	S	[null]	89	Oslo, Norway Cameron, WI
91	3	0	Oreskovic, Miss. Jelka	female	23.0	0	0	315085	8.6625	[null]	S	[null]	[null]	[null]
92	3	0	Oreskovic, Miss. Marija	female	20.0	0	0	315096	8.6625	[null]	S	[null]	[null]	[null]
93	3	0	Oreskovic, Mr. Luka	male	20.0	0	0	315094	8.6625	[null]	S	[null]	[null]	[null]
94	3	0	Osen, Mr. Olaf Elon	male	16.0	0	0	7534	9.2167	[null]	S	[null]	[null]	[null]
95	3	1	Osman, Mrs. Mara	female	31.0	0	0	349244	8.6833	[null]	S	[null]	[null]	[null]
96	3	0	O'Sullivan, Miss. Bridget Mary	female	[null]	0	0	330909	7.6292	[null]	Q	[null]	[null]	[null]
97	3	0	Palsson, Master. Gosta Leonard	male	2.0	3	1	349909	21.075	[null]	S	[null]	4	[null]
98	3	0	Palsson, Master. Paul Folke	male	6.0	3	1	349909	21.075	[null]	S	[null]	[null]	[null]
99	3	0	Palsson, Miss. Stina Viola	female	3.0	3	1	349909	21.075	[null]	S	[null]	[null]	[null]
100	3	0	Palsson, Miss. Torborg Danira	female	8.0	3	1	349909	21.075	[null]	S	[null]	[null]	[null]

Rows: 1-100 | Columns: 14

Note

vastorbit offers a wide range of sample datasets that are ideal for training and testing purposes. You can explore the full list of available datasets in the Datasets, which provides detailed information on each dataset and how to use them effectively. These datasets are invaluable resources for honing your data analysis and machine learning skills within the vastorbit environment.

We can check the size of the dataset by:

len(data)

For some reason, if we did not need the entire dataset, then we can conveniently sample it using the sample function:

subsample = vdf.sample(x = 0.33)

	123 pclass Integer	123 survived Integer	Abc name Varchar(164)	Abc sex Varchar(20)	123 age Double	123 sibsp Integer	123 parch Integer	Abc ticket Varchar(36)	123 fare Double	Abc cabin Varchar(30)	Abc embarked Varchar(20)	Abc boat Varchar(100)	123 body Integer	Abc home.dest Varchar(100)
1	1	1	Sagesser, Mlle. Emma	female	24.0	0	0	PC 17477	69.3	B35	C	9	[null]	[null]
2	1	1	Serepeca, Miss. Augusta	female	30.0	0	0	113798	31.0	[null]	C	4	[null]	[null]
3	1	1	Seward, Mr. Frederic Kimber	male	34.0	0	0	113794	26.55	[null]	S	7	[null]	New York, NY
4	1	0	Silvey, Mr. William Baird	male	50.0	1	0	13507	55.9	E44	S	[null]	[null]	Duluth, MN
5	1	1	Silvey, Mrs. William Baird (Alice Munger)	female	39.0	1	0	13507	55.9	E44	S	11	[null]	Duluth, MN
6	1	1	Sloper, Mr. William Thompson	male	28.0	0	0	113788	35.5	A6	S	7	[null]	New Britain, CT
7	1	1	Snyder, Mr. John Pillsbury	male	24.0	1	0	21228	82.2667	B45	S	7	[null]	Minneapolis, MN
8	1	1	Snyder, Mrs. John Pillsbury (Nelle Stevenson)	female	23.0	1	0	21228	82.2667	B45	S	7	[null]	Minneapolis, MN
9	1	1	Spedden, Mr. Frederic Oakley	male	45.0	1	1	16966	134.5	E34	C	3	[null]	Tuxedo Park, NY
10	1	1	Spedden, Mrs. Frederic Oakley (Margaretta Corning Stone)	female	40.0	1	1	16966	134.5	E34	C	3	[null]	Tuxedo Park, NY
11	1	1	Spencer, Mrs. William Augustus (Marie Eugenie)	female	[null]	1	0	PC 17569	146.5208	B78	C	6	[null]	Paris, France
12	1	1	Stahelin-Maeglin, Dr. Max	male	32.0	0	0	13214	30.5	B50	C	3	[null]	Basel, Switzerland
13	1	1	Stengel, Mr. Charles Emil Henry	male	54.0	1	0	11778	55.4417	C116	C	1	[null]	Newark, NJ
14	1	1	Stengel, Mrs. Charles Emil Henry (Annie May Morris)	female	43.0	1	0	11778	55.4417	C116	C	5	[null]	Newark, NJ
15	1	1	Stephenson, Mrs. Walter Bertram (Martha Eustis)	female	52.0	1	0	36947	78.2667	D20	C	4	[null]	Haverford, PA
16	1	0	Sutton, Mr. Frederick	male	61.0	0	0	36963	32.3208	D50	S	[null]	46	Haddenfield, NJ
17	1	0	Taussig, Mr. Emil	male	52.0	1	1	110413	79.65	E67	S	[null]	[null]	New York, NY
18	1	1	Taylor, Mrs. Elmer Zebley (Juliet Cummins Wright)	female	[null]	1	0	19996	52.0	C126	S	5 7	[null]	London / East Orange, NJ
19	1	0	Van der hoef, Mr. Wyckoff	male	61.0	0	0	111240	33.5	B19	S	[null]	245	Brooklyn, NY
20	1	0	White, Mr. Richard Frasar	male	21.0	0	1	35281	77.2875	D26	S	[null]	169	Brunswick, ME
21	1	1	Wick, Miss. Mary Natalie	female	31.0	0	2	36928	164.8667	C7	S	8	[null]	Youngstown, OH
22	1	1	Wilson, Miss. Helen Alice	female	31.0	0	0	16966	134.5	E39 E41	C	3	[null]	[null]
23	1	1	Woolner, Mr. Hugh	male	[null]	0	0	19947	35.5	C52	S	D	[null]	London, England
24	2	1	Abelson, Mrs. Samuel (Hannah Wizosky)	female	28.0	1	0	P/PP 3381	24.0	[null]	C	10	[null]	Russia New York, NY
25	2	0	Aldworth, Mr. Charles Augustus	male	30.0	0	0	248744	13.0	[null]	S	[null]	[null]	Bryn Mawr, PA, USA
26	2	0	Andrew, Mr. Edgardo Samuel	male	18.0	0	0	231945	11.5	[null]	S	[null]	[null]	Buenos Aires, Argentina / New Jersey, NJ
27	2	0	Bailey, Mr. Percy Andrew	male	18.0	0	0	29108	11.5	[null]	S	[null]	[null]	Penzance, Cornwall / Akron, OH
28	2	1	Ball, Mrs. (Ada E Hall)	female	36.0	0	0	28551	13.0	D	S	10	[null]	Bristol, Avon / Jacksonville, FL
29	2	1	Beane, Mr. Edward	male	32.0	1	0	2908	26.0	[null]	S	13	[null]	Norwich / New York, NY
30	2	1	Beane, Mrs. Edward (Ethel Clarke)	female	19.0	1	0	2908	26.0	[null]	S	13	[null]	Norwich / New York, NY
31	2	1	Becker, Master. Richard F	male	1.0	2	1	230136	39.0	F4	S	11	[null]	Guntur, India / Benton Harbour, MI
32	2	0	Botsford, Mr. William Hull	male	26.0	0	0	237670	13.0	[null]	S	[null]	[null]	Elmira, NY / Orange, NJ
33	2	1	Bryhl, Miss. Dagmar Jenny Ingeborg	female	20.0	1	0	236853	26.0	[null]	S	12	[null]	Skara, Sweden / Rockford, IL
34	2	0	Butler, Mr. Reginald Fenton	male	25.0	0	0	234686	13.0	[null]	S	[null]	97	Southsea, Hants
35	2	0	Byles, Rev. Thomas Roussel Davids	male	42.0	0	0	244310	13.0	[null]	S	[null]	[null]	London
36	2	1	Cameron, Miss. Clear Annie	female	35.0	0	0	F.C.C. 13528	21.0	[null]	S	14	[null]	Mamaroneck, NY
37	2	0	Campbell, Mr. William	male	[null]	0	0	239853	0.0	[null]	S	[null]	[null]	Belfast
38	2	0	Chapman, Mr. Charles Henry	male	52.0	0	0	248731	13.5	[null]	S	[null]	130	Bronx, NY
39	2	0	Chapman, Mr. John Henry	male	37.0	1	0	SC/AH 29037	26.0	[null]	S	[null]	17	Cornwall / Spokane, WA
40	2	0	Chapman, Mrs. John Henry (Sara Elizabeth Lawry)	female	29.0	1	0	SC/AH 29037	26.0	[null]	S	[null]	[null]	Cornwall / Spokane, WA
41	2	1	Collyer, Mrs. Harvey (Charlotte Annie Tate)	female	31.0	1	1	C.A. 31921	26.25	[null]	S	14	[null]	Bishopstoke, Hants / Fayette Valley, ID
42	2	0	Corbett, Mrs. Walter H (Irene Colvin)	female	30.0	0	0	237249	13.0	[null]	S	[null]	[null]	Provo, UT
43	2	0	Corey, Mrs. Percy C (Mary Phyllis Elizabeth Miller)	female	[null]	0	0	F.C.C. 13534	21.0	[null]	S	[null]	[null]	Upper Burma, India Pittsburgh, PA
44	2	0	Davies, Mr. Charles Henry	male	18.0	0	0	S.O.C. 14879	73.5	[null]	S	[null]	[null]	Lyndhurst, England
45	2	1	del Carlo, Mrs. Sebastiano (Argenia Genovesi)	female	24.0	1	0	SC/PARIS 2167	27.7208	[null]	C	12	[null]	Lucca, Italy / California
46	2	0	Downton, Mr. William James	male	54.0	0	0	28403	26.0	[null]	S	[null]	[null]	Holley, NY
47	2	1	Drew, Mrs. James Vivian (Lulu Thorne Christian)	female	34.0	1	1	28220	32.5	[null]	S	10	[null]	Greenport, NY
48	2	1	Duran y More, Miss. Florentina	female	30.0	1	0	SC/PARIS 2148	13.8583	[null]	C	12	[null]	Barcelona, Spain / Havana, Cuba
49	2	0	Fillbrook, Mr. Joseph Charles	male	18.0	0	0	C.A. 15185	10.5	[null]	S	[null]	[null]	Cornwall / Houghton, MI
50	2	0	Fox, Mr. Stanley Hubert	male	36.0	0	0	229236	13.0	[null]	S	[null]	236	Rochester, NY
51	2	0	Gaskell, Mr. Alfred	male	16.0	0	0	239865	26.0	[null]	S	[null]	[null]	Liverpool / Montreal, PQ
52	2	0	Gavey, Mr. Lawrence	male	26.0	0	0	31028	10.5	[null]	S	[null]	[null]	Guernsey / Elizabeth, NJ
53	2	0	Giles, Mr. Frederick Edward	male	21.0	1	0	28134	11.5	[null]	S	[null]	[null]	Cornwall / Camden, NJ
54	2	0	Giles, Mr. Ralph	male	24.0	0	0	248726	13.5	[null]	S	[null]	297	West Kensington, London
55	2	0	Hale, Mr. Reginald	male	30.0	0	0	250653	13.0	[null]	S	[null]	75	Auburn, NY
56	2	1	Hamalainen, Master. Viljo	male	0.67	1	1	250649	14.5	[null]	S	4	[null]	Detroit, MI
57	2	0	Harbeck, Mr. William H	male	44.0	0	0	248746	13.0	[null]	S	[null]	35	Seattle, WA / Toledo, OH
58	2	1	Harper, Miss. Annie Jessie "Nina"	female	6.0	0	1	248727	33.0	[null]	S	11	[null]	Denmark Hill, Surrey / Chicago
59	2	1	Harris, Mr. George	male	62.0	0	0	S.W./PP 752	10.5	[null]	S	15	[null]	London
60	2	0	Harris, Mr. Walter	male	30.0	0	0	W/C 14208	10.5	[null]	S	[null]	[null]	Walthamstow, England
61	2	1	Hart, Miss. Eva Miriam	female	7.0	0	2	F.C.C. 13529	26.25	[null]	S	14	[null]	Ilford, Essex / Winnipeg, MB
62	2	0	Herman, Mr. Samuel	male	49.0	1	2	220845	65.0	[null]	S	[null]	[null]	Somerset / Bernardsville, NJ
63	2	0	Hold, Mr. Stephen	male	44.0	1	0	26707	26.0	[null]	S	[null]	[null]	England / Sacramento, CA
64	2	1	Hosono, Mr. Masabumi	male	42.0	0	0	237798	13.0	[null]	S	10	[null]	Tokyo, Japan
65	2	1	Ilett, Miss. Bertha	female	17.0	0	0	SO/C 14885	10.5	[null]	S	[null]	[null]	Guernsey
66	2	1	Jacobsohn, Mrs. Sidney Samuel (Amy Frances Christy)	female	24.0	2	1	243847	27.0	[null]	S	12	[null]	London
67	2	0	Jarvis, Mr. John Denzil	male	47.0	0	0	237565	15.0	[null]	S	[null]	[null]	North Evington, England
68	2	0	Jefferys, Mr. Ernest Wilfred	male	22.0	2	0	C.A. 31029	31.5	[null]	S	[null]	[null]	Guernsey / Elizabeth, NJ
69	2	0	Kantor, Mr. Sinai	male	34.0	1	0	244367	26.0	[null]	S	[null]	283	Moscow / Bronx, NY
70	2	1	Kantor, Mrs. Sinai (Miriam Sternin)	female	24.0	1	0	244367	26.0	[null]	S	12	[null]	Moscow / Bronx, NY
71	2	1	Kelly, Mrs. Florence "Fannie"	female	45.0	0	0	223596	13.5	[null]	S	9	[null]	London / New York, NY
72	2	0	Kirkland, Rev. Charles Leonard	male	57.0	0	0	219533	12.35	[null]	Q	[null]	[null]	Glasgow / Bangor, ME
73	2	1	Laroche, Miss. Simonne Marie Anne Andree	female	3.0	1	2	SC/Paris 2123	41.5792	[null]	C	14	[null]	Paris / Haiti
74	2	1	Lehmann, Miss. Bertha	female	17.0	0	0	SC 1748	12.0	[null]	C	12	[null]	Berne, Switzerland / Central City, IA
75	2	0	Levy, Mr. Rene Jacques	male	36.0	0	0	SC/Paris 2163	12.875	D	C	[null]	[null]	Montreal, PQ
76	2	1	Louch, Mrs. Charles Alexander (Alice Adelaide Slow)	female	42.0	1	0	SC/AH 3085	26.0	[null]	S	[null]	[null]	Weston-Super-Mare, Somerset
77	2	0	Mack, Mrs. (Mary)	female	57.0	0	0	S.O./P.P. 3	10.5	E77	S	[null]	52	Southampton / New York, NY
78	2	1	Mallet, Master. Andre	male	1.0	0	2	S.C./PARIS 2079	37.0042	[null]	C	10	[null]	Paris / Montreal, PQ
79	2	1	Mallet, Mrs. Albert (Antoinette Magnin)	female	24.0	1	1	S.C./PARIS 2079	37.0042	[null]	C	10	[null]	Paris / Montreal, PQ
80	2	0	McKane, Mr. Peter David	male	46.0	0	0	28403	26.0	[null]	S	[null]	[null]	Rochester, NY
81	2	0	Mitchell, Mr. Henry Michael	male	70.0	0	0	C.A. 24580	10.5	[null]	S	[null]	[null]	Guernsey / Montclair, NJ and/or Toledo, Ohio
82	3	1	McCoy, Miss. Alicia	female	[null]	2	0	367226	23.25	[null]	Q	16	[null]	[null]
83	3	1	McDermott, Miss. Brigdet Delia	female	[null]	0	0	330932	7.7875	[null]	Q	13	[null]	[null]
84	3	0	McMahon, Mr. Martin	male	[null]	0	0	370372	7.75	[null]	Q	[null]	[null]	[null]
85	3	0	Meanwell, Miss. (Marion Ogden)	female	[null]	0	0	SOTON/O.Q. 392087	8.05	[null]	S	[null]	[null]	[null]
86	3	1	Midtsjo, Mr. Karl Albert	male	21.0	0	0	345501	7.775	[null]	S	15	[null]	[null]
87	3	0	Mineff, Mr. Ivan	male	24.0	0	0	349233	7.8958	[null]	S	[null]	[null]	[null]
88	3	1	Moran, Miss. Bertha	female	[null]	1	0	371110	24.15	[null]	Q	16	[null]	[null]
89	3	0	Moran, Mr. Daniel J	male	[null]	1	0	371110	24.15	[null]	Q	[null]	[null]	[null]
90	3	0	Moran, Mr. James	male	[null]	0	0	330877	8.4583	[null]	Q	[null]	[null]	[null]
91	3	1	Moss, Mr. Albert Johan	male	[null]	0	0	312991	7.775	[null]	S	B	[null]	[null]
92	3	1	Moubarek, Master. Gerios	male	[null]	1	1	2661	15.2458	[null]	C	C	[null]	[null]
93	3	1	Moubarek, Mrs. George (Omine "Amenia" Alexander)	female	[null]	0	2	2661	15.2458	[null]	C	C	[null]	[null]
94	3	1	Moussa, Mrs. (Mantoura Boulos)	female	[null]	0	0	2626	7.2292	[null]	C	[null]	[null]	[null]
95	3	0	Moutal, Mr. Rahamin Haim	male	[null]	0	0	374746	8.05	[null]	S	[null]	[null]	[null]
96	3	1	Mulvihill, Miss. Bertha E	female	24.0	0	0	382653	7.75	[null]	Q	15	[null]	[null]
97	3	0	Murdlin, Mr. Joseph	male	[null]	0	0	A./5. 3235	8.05	[null]	S	[null]	[null]	[null]
98	3	1	Murphy, Miss. Katherine "Kate"	female	[null]	1	0	367230	15.5	[null]	Q	16	[null]	[null]
99	3	1	Murphy, Miss. Nora	female	[null]	0	0	36568	15.5	[null]	Q	16	[null]	[null]
100	3	0	Myhrman, Mr. Pehr Fabian Oliver Malkolm	male	18.0	0	0	347078	7.75	[null]	S	[null]	[null]	[null]

Rows: 1-100 of 424 | Columns: 14

We can check the size of the dataset to confirm the size is smaller than the original dataset:

len(subsample)

In the above example, we used the x parameter which corresponds to ratio. We can also use the n parameter which corresponds to the number of records to be sampled.

subsample = vdf.sample(n = 100)

To confirm, if we obtained the right size, we can check it:

len(subsample)

In order to tackle data with skewed distributions, we can use the stratified option for the method.

Let us ensure that the classes “pclass” and “sex” are proportionally represented:

subsample = vdf.sample(
    x = 0.33,
    method = "stratified",
    by = ["pclass", "sex"],
)

	123 pclass Integer	123 survived Integer	Abc name Varchar(164)	Abc sex Varchar(20)	123 age Double	123 sibsp Integer	123 parch Integer	Abc ticket Varchar(36)	123 fare Double	Abc cabin Varchar(30)	Abc embarked Varchar(20)	Abc boat Varchar(100)	123 body Integer	Abc home.dest Varchar(100)
1	1	1	Swift, Mrs. Frederick Joel (Margaret Welles Barron)	female	48.0	0	0	17466	25.9292	D17	S	8	[null]	Brooklyn, NY
2	1	1	Kreuchen, Miss. Emilie	female	39.0	0	0	24160	211.3375	[null]	S	2	[null]	[null]
3	1	1	Fortune, Miss. Mabel Helen	female	23.0	3	2	19950	263.0	C23 C25 C27	S	10	[null]	Winnipeg, MB
4	1	1	Ryerson, Miss. Emily Borie	female	18.0	2	2	PC 17608	262.375	B57 B59 B63 B66	C	4	[null]	Haverford, PA / Cooperstown, NY
5	1	0	McCaffry, Mr. Thomas Francis	male	46.0	0	0	13050	75.2417	C6	C	[null]	292	Vancouver, BC
6	1	0	Straus, Mr. Isidor	male	67.0	1	0	PC 17483	221.7792	C55 C57	S	[null]	96	New York, NY
7	1	0	Beattie, Mr. Thomson	male	36.0	0	0	13050	75.2417	C6	C	A	[null]	Winnipeg, MN
8	1	1	Carter, Mr. William Ernest	male	36.0	1	2	113760	120.0	B96 B98	S	C	[null]	Bryn Mawr, PA
9	1	0	Chaffee, Mr. Herbert Fuller	male	46.0	1	0	W.E.P. 5734	61.175	E31	S	[null]	[null]	Amenia, ND
10	1	1	Frauenthal, Mr. Isaac Gerald	male	43.0	1	0	17765	27.7208	D40	C	5	[null]	New York, NY
11	2	1	Leitch, Miss. Jessie Wills	female	[null]	0	0	248727	33.0	[null]	S	11	[null]	London / Chicago, IL
12	2	1	Richards, Mrs. Sidney (Emily Hocking)	female	24.0	2	3	29106	18.75	[null]	S	4	[null]	Cornwall / Akron, OH
13	2	0	Levy, Mr. Rene Jacques	male	36.0	0	0	SC/Paris 2163	12.875	D	C	[null]	[null]	Montreal, PQ
14	3	0	Hagardon, Miss. Kate	female	17.0	0	0	AQ/3. 30631	7.7333	[null]	Q	[null]	[null]	[null]
15	3	1	Dean, Miss. Elizabeth Gladys "Millvina"	female	0.17	1	2	C.A. 2315	20.575	[null]	S	10	[null]	Devon, England Wichita, KS
16	3	1	Jansson, Mr. Carl Olof	male	21.0	0	0	350034	7.7958	[null]	S	A	[null]	[null]
17	3	0	Johansson, Mr. Gustaf Joel	male	33.0	0	0	7540	8.6542	[null]	S	[null]	285	[null]
18	3	0	Lyntakoff, Mr. Stanko	male	[null]	0	0	349235	7.8958	[null]	S	[null]	[null]	[null]
19	3	0	Makinen, Mr. Kalle Edvard	male	29.0	0	0	STON/O 2. 3101268	7.925	[null]	S	[null]	[null]	[null]
20	3	0	Oreskovic, Mr. Luka	male	20.0	0	0	315094	8.6625	[null]	S	[null]	[null]	[null]
21	3	0	Stanley, Mr. Edward Roland	male	21.0	0	0	A/4 45380	8.05	[null]	S	[null]	[null]	[null]
22	1	1	Homer, Mr. Harry ("Mr E Haven")	male	35.0	0	0	111426	26.55	[null]	C	15	[null]	Indianapolis, IN
23	2	1	Jacobsohn, Mrs. Sidney Samuel (Amy Frances Christy)	female	24.0	2	1	243847	27.0	[null]	S	12	[null]	London
24	2	1	Keane, Miss. Nora A	female	[null]	0	0	226593	12.35	E101	Q	10	[null]	Harrisburg, PA
25	2	1	Becker, Miss. Ruth Elizabeth	female	12.0	2	1	230136	39.0	F4	S	13	[null]	Guntur, India / Benton Harbour, MI
26	2	1	Reynaldo, Ms. Encarnacion	female	28.0	0	0	230434	13.0	[null]	S	9	[null]	Spain
27	2	0	Greenberg, Mr. Samuel	male	52.0	0	0	250647	13.0	[null]	S	[null]	19	Bronx, NY
28	2	0	Harris, Mr. Walter	male	30.0	0	0	W/C 14208	10.5	[null]	S	[null]	[null]	Walthamstow, England
29	2	0	Myles, Mr. Thomas Francis	male	62.0	0	0	240276	9.6875	[null]	Q	[null]	[null]	Cambridge, MA
30	2	0	Sobey, Mr. Samuel James Hayden	male	25.0	0	0	C.A. 29178	13.0	[null]	S	[null]	[null]	Cornwall / Houghton, MI
31	2	1	Becker, Master. Richard F	male	1.0	2	1	230136	39.0	F4	S	11	[null]	Guntur, India / Benton Harbour, MI
32	3	1	Glynn, Miss. Mary Agatha	female	[null]	0	0	335677	7.75	[null]	Q	13	[null]	Co Clare, Ireland Washington, DC
33	3	1	Drapkin, Miss. Jennie	female	23.0	0	0	SOTON/OQ 392083	8.05	[null]	S	[null]	[null]	London New York, NY
34	3	1	Nilsson, Miss. Berta Olivia	female	18.0	0	0	347066	7.775	[null]	S	D	[null]	[null]
35	3	1	Ohman, Miss. Velin	female	22.0	0	0	347085	7.775	[null]	S	C	[null]	[null]
36	3	0	Pettersson, Miss. Ellen Natalia	female	18.0	0	0	347087	7.775	[null]	S	[null]	[null]	[null]
37	3	1	Stanley, Miss. Amy Zillah Elsie	female	23.0	0	0	CA. 2314	7.55	[null]	S	C	[null]	[null]
38	3	0	Badt, Mr. Mohamed	male	40.0	0	0	2623	7.225	[null]	C	[null]	[null]	[null]
39	3	1	Buckley, Mr. Daniel	male	21.0	0	0	330920	7.8208	[null]	Q	13	[null]	Kingwilliamstown, Co Cork, Ireland New York, NY
40	3	0	Denkoff, Mr. Mitto	male	[null]	0	0	349225	7.8958	[null]	S	[null]	[null]	Bulgaria Coon Rapids, IA
41	3	0	Dyker, Mr. Adolf Fredrik	male	23.0	1	0	347072	13.9	[null]	S	[null]	[null]	West Haven, CT
42	3	0	Ekstrom, Mr. Johan	male	45.0	0	0	347061	6.975	[null]	S	[null]	[null]	Effington Rut, SD
43	3	0	Linehan, Mr. Michael	male	[null]	0	0	330971	7.8792	[null]	Q	[null]	[null]	[null]
44	3	1	Sundman, Mr. Johan Julian	male	44.0	0	0	STON/O 2. 3101269	7.925	[null]	S	15	[null]	[null]
45	1	1	Kenyon, Mrs. Frederick R (Marion)	female	[null]	1	0	17464	51.8625	D21	S	8	[null]	Southington / Noank, CT
46	1	1	Penasco y Castellana, Mrs. Victor de Satode (Maria Josefa Perez de Soto y Vallejo)	female	17.0	1	0	PC 17758	108.9	C65	C	8	[null]	Madrid, Spain
47	1	0	Walker, Mr. William Anderson	male	47.0	0	0	36967	34.0208	D46	S	[null]	[null]	East Orange, NJ
48	1	1	Calderhead, Mr. Edward Pennington	male	42.0	0	0	PC 17476	26.2875	E24	S	5	[null]	New York, NY
49	1	1	Hawksford, Mr. Walter James	male	[null]	0	0	16988	30.0	D45	S	3	[null]	Kingston, Surrey
50	2	1	Ware, Mrs. John James (Florence Louise Long)	female	31.0	0	0	CA 31352	21.0	[null]	S	10	[null]	Bristol, England / New Britain, CT
51	2	1	Phillips, Miss. Kate Florence ("Mrs Kate Louise Phillips Marshall")	female	19.0	0	0	250655	26.0	[null]	S	11	[null]	Worcester, England
52	2	0	Gaskell, Mr. Alfred	male	16.0	0	0	239865	26.0	[null]	S	[null]	[null]	Liverpool / Montreal, PQ
53	2	0	Maybery, Mr. Frank Hubert	male	40.0	0	0	239059	16.0	[null]	S	[null]	[null]	Weston-Super-Mare / Moose Jaw, SK
54	2	0	Milling, Mr. Jacob Christian	male	48.0	0	0	234360	13.0	[null]	S	[null]	271	Copenhagen, Denmark
55	2	1	Navratil, Master. Michel M	male	3.0	1	1	230080	26.0	F2	S	D	[null]	Nice, France
56	2	0	Pain, Dr. Alfred	male	23.0	0	0	244278	10.5	[null]	S	[null]	[null]	Hamilton, ON
57	3	1	Abelseth, Miss. Karen Marie	female	16.0	0	0	348125	7.65	[null]	S	16	[null]	Norway Los Angeles, CA
58	3	1	McGowan, Miss. Anna "Annie"	female	15.0	0	0	330923	8.0292	[null]	Q	[null]	[null]	[null]
59	3	1	Hirvonen, Mrs. Alexander (Helga E Lindqvist)	female	22.0	1	1	3101298	12.2875	[null]	S	15	[null]	[null]
60	3	0	Fleming, Miss. Honora	female	[null]	0	0	364859	7.75	[null]	Q	[null]	[null]	[null]
61	3	0	Angheloff, Mr. Minko	male	26.0	0	0	349202	7.8958	[null]	S	[null]	[null]	Bulgaria Chicago, IL
62	3	1	Jussila, Mr. Eiriik	male	32.0	0	0	STON/O 2. 3101286	7.925	[null]	S	15	[null]	[null]
63	3	0	Kilgannon, Mr. Thomas J	male	[null]	0	0	36865	7.7375	[null]	Q	[null]	[null]	[null]
64	3	1	Lulic, Mr. Nikola	male	27.0	0	0	315098	8.6625	[null]	S	15	[null]	[null]
65	3	0	Patchett, Mr. George	male	19.0	0	0	358585	14.5	[null]	S	[null]	[null]	[null]
66	3	0	Windelov, Mr. Einar	male	21.0	0	0	SOTON/OQ 3101317	7.25	[null]	S	[null]	[null]	[null]
67	1	1	Lurette, Miss. Elise	female	58.0	0	0	PC 17569	146.5208	B80	C	[null]	[null]	[null]
68	1	1	Goldenberg, Mrs. Samuel L (Edwiga Grabowska)	female	[null]	1	0	17453	89.1042	C92	C	5	[null]	Paris, France / New York, NY
69	1	1	Bird, Miss. Ellen	female	29.0	0	0	PC 17483	221.7792	C97	S	8	[null]	[null]
70	1	1	Andrews, Miss. Kornelia Theodosia	female	63.0	1	0	13502	77.9583	D7	S	10	[null]	Hudson, NY
71	1	0	Jones, Mr. Charles Cresson	male	46.0	0	0	694	26.0	[null]	S	[null]	80	Bennington, VT
72	1	0	Brewe, Dr. Arthur Jackson	male	[null]	0	0	112379	39.6	[null]	C	[null]	[null]	Philadelphia, PA
73	1	1	Harder, Mr. George Achilles	male	25.0	1	0	11765	55.4417	E50	C	5	[null]	Brooklyn, NY
74	2	1	Wells, Mrs. Arthur Henry ("Addie" Dart Trevaskis)	female	29.0	0	2	29103	23.0	[null]	S	14	[null]	Cornwall / Akron, OH
75	2	1	Brown, Mrs. Thomas William Solomon (Elizabeth Catherine Ford)	female	40.0	1	1	29750	39.0	[null]	S	14	[null]	Cape Town, South Africa / Seattle, WA
76	2	1	Duran y More, Miss. Florentina	female	30.0	1	0	SC/PARIS 2148	13.8583	[null]	C	12	[null]	Barcelona, Spain / Havana, Cuba
77	2	0	Louch, Mr. Charles Alexander	male	50.0	1	0	SC/AH 3085	26.0	[null]	S	[null]	121	Weston-Super-Mare, Somerset
78	2	0	Mallet, Mr. Albert	male	31.0	1	1	S.C./PARIS 2079	37.0042	[null]	C	[null]	[null]	Paris / Montreal, PQ
79	3	0	Andersson, Miss. Sigrid Elisabeth	female	11.0	4	2	347082	31.275	[null]	S	[null]	[null]	Sweden Winnipeg, MN
80	3	1	Asplund, Mrs. Carl Oscar (Selma Augusta Emilia Johansson)	female	38.0	1	5	347077	31.3875	[null]	S	15	[null]	Sweden Worcester, MA
81	3	0	Naughton, Miss. Hannah	female	[null]	0	0	365237	7.75	[null]	Q	[null]	[null]	[null]
82	3	1	Murphy, Miss. Katherine "Kate"	female	[null]	1	0	367230	15.5	[null]	Q	16	[null]	[null]
83	3	0	Van Impe, Mrs. Jean Baptiste (Rosalie Paula Govaert)	female	30.0	1	1	345773	24.15	[null]	S	[null]	[null]	[null]
84	3	0	Panula, Mrs. Juha (Maria Emilia Ojala)	female	41.0	0	5	3101295	39.6875	[null]	S	[null]	[null]	[null]
85	3	1	Asplund, Master. Edvin Rojj Felix	male	3.0	4	2	347077	31.3875	[null]	S	15	[null]	Sweden Worcester, MA
86	3	0	Braund, Mr. Owen Harris	male	22.0	1	0	A/5 21171	7.25	[null]	S	[null]	[null]	Bridgerule, Devon
87	3	0	Danbom, Mr. Ernst Gilbert	male	34.0	1	1	347080	14.4	[null]	S	[null]	197	Stanton, IA
88	3	0	Elias, Mr. Joseph Jr	male	17.0	1	1	2690	7.2292	[null]	C	[null]	[null]	[null]
89	3	1	Johnson, Master. Harold Theodor	male	4.0	1	1	347742	11.1333	[null]	S	15	[null]	[null]
90	3	0	Saether, Mr. Simon Sivertsen	male	38.5	0	0	SOTON/O.Q. 3101262	7.25	[null]	S	[null]	32	[null]
91	3	0	Thomas, Mr. Tannous	male	[null]	0	0	2684	7.225	[null]	C	[null]	[null]	[null]
92	3	0	Waelens, Mr. Achille	male	22.0	0	0	345767	9.0	[null]	S	[null]	[null]	Antwerp, Belgium / Stanton, OH
93	1	1	Bowen, Miss. Grace Scott	female	45.0	0	0	PC 17608	262.375	[null]	C	4	[null]	Cooperstown, NY
94	1	0	Lindeberg-Lind, Mr. Erik Gustaf ("Mr Edward Lingrey")	male	42.0	0	0	17475	26.55	[null]	S	[null]	[null]	Stockholm, Sweden
95	1	0	Smart, Mr. John Montgomery	male	56.0	0	0	113792	26.55	[null]	S	[null]	[null]	New York, NY
96	1	1	Tucker, Mr. Gilbert Milligan Jr	male	31.0	0	0	2543	28.5375	C53	C	7	[null]	Albany, NY
97	1	0	Astor, Col. John Jacob	male	47.0	1	0	PC 17757	227.525	C62 C64	C	[null]	124	New York, NY
98	2	1	Brown, Miss. Amelia "Mildred"	female	24.0	0	0	248733	13.0	F33	S	11	[null]	London / Montreal, PQ
99	3	1	Daly, Miss. Margaret Marcella "Maggie"	female	30.0	0	0	382650	6.95	[null]	Q	15	[null]	Co Athlone, Ireland New York, NY
100	3	1	Johnson, Mrs. Oscar W (Elisabeth Vilhelmina Berg)	female	27.0	0	2	347742	11.1333	[null]	S	15	[null]	[null]

Rows: 1-100 of 433 | Columns: 14

See also

VastFrame.balance() : Balances the VastFrame.

VastFrame.isin() : Checks whether specific records are in the VastFrame.