topic Re: calculate quantile in SAS Procedures

calculate quantile

mei — Tue, 19 Jun 2012 01:50:34 GMT

Dear Sir,

I wish to split my sample to 3 groups based on total assets (variable:at), ie to small firm, medium firm and big firm. this means i need to calculate the 1/3 quantile, 2/3 quantile for the variable.

How do i write that in the program?

also: if i wish to split to 4 parts, i suppose Q1, median, Q3 that is generated from the normal univariate procedure would be fine right?

Thanks a lot!!

Re: calculate quantile

MikeZdeb — Tue, 19 Jun 2012 02:18:12 GMT

hi ... quantiles and the median are based on counts, not magnitude of numbers so that approach will not categorize small/ medium/large

for example, if I looked at this data, I might say that 1 is small, 100 is medium, 1000 is large ... but the quantiles and median don't say that

data test;

input assets @@;

datalines;

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10 10 1000

;

proc univariate data=test;

ods select quantiles;

run;

Variable: assets

Quantiles (Definition 5)

Quantile Estimate

100% Max 1000

99% 1000

95% 100

90% 100

75% Q3 1

50% Median 1

25% Q1 1

10% 1

5% 1

1% 1

0% Min 1

Re: calculate quantile

mei — Tue, 19 Jun 2012 02:22:35 GMT

it is okay, i just want the count as my data size is very big, up to 20,000 observations. i just need to split them to 3 groups.

can you guide me in writing the codes to 3 parts?

Re: calculate quantile

MikeZdeb — Tue, 19 Jun 2012 02:32:50 GMT

hi ... specify the number of groups in GROUPS= ... the lowest group is always 0

with three groups, the value of ASSET_GROUP will be 0, 1, 2

proc rank data=test out=test_group groups=3 ties=low;

var assets;

ranks asset_group;

run;

(you can look at online help for an explanation of TIES=)