Need help on histogram range

[Eunsang Jee]

I hope everything to work out well in your lives.

Here's the question: How can I draw histograms for each year around specific periods?

Data looks like:

FirmNo. Yr FDate PDate
002410 2010 20100120 20100221
002410 2011 20110121 20110222
002410 2012 20120124 20120222
002319 2010 20100127 20100219
002319 2011 20110124 20110220
002319 2012 20120119 20120222

When I make histogram, it shows whole period on x axis, so it is impossible for me to look at frequency of the dates (FDate and PDate each) that the firms make announcements.

I want the histogram each year to show certain periods only. (e.g. 20100101 ~ 20100228)

Thank you in advance, and please let me know if I have to give more information.

[Nick Cox]

It's hard to comment on your histogram (we can't see it) or your histogram command (you don't show that either).

What can be guessed is that your daily dates are not fit for most purposes. See

help datetime

for guidance. Here is some technique

clear
input str6 FirmNo Yr long(FDate PDate)
002410 2010 20100120 20100221
002410 2011 20110121 20110222
002410 2012 20120124 20120222
002319 2010 20100127 20100219
002319 2011 20110124 20110220
002319 2012 20120119 20120222
end

gen GoodPDate = daily(string(PDate, "%8.0f"), "YMD")

format GoodPDate %td

list, sep(0)

     +-------------------------------------------------+
     | FirmNo     Yr      FDate      PDate   GoodPDate |
     |-------------------------------------------------|
  1. | 002410   2010   20100120   20100221   21feb2010 |
  2. | 002410   2011   20110121   20110222   22feb2011 |
  3. | 002410   2012   20120124   20120222   22feb2012 |
  4. | 002319   2010   20100127   20100219   19feb2010 |
  5. | 002319   2011   20110124   20110220   20feb2011 |
  6. | 002319   2012   20120119   20120222   22feb2012 |
     +-------------------------------------------------+

Perhaps

... if inrange(GoodPDate, mdy(1,1,2010), mdy(2, 28, 2010))

is the qualifier you are looking for. In fact,

.. if inrange(PDate, 20100101, 20100228)

should also work, but don't be misled into thinking that such dates are good for most Stata purposes.

[Eunsang Jee]

Thank you so much!

But what type of date is more of Stata purpose? I have very little knowledge about the software... please understand.

[Nick Cox]

I understand. That is why I advised you generally to read

help datetime

and showed you specifically how to get Stata date variables out of your data.