Hello

I have a vector a =(-2,0,0,0,1,0,0,3,0,0,-4)

I want to replace all zeros into previous non-zero state. So for instance the above vector should be converted into:

a= (-2,-2,-2,-2,1,1,1,3,3,3,-4)

I tried many things and finally concluded that probably(?) rollapply may be the best way?

I tried
f= function(x){
                ifelse(x==0,Lag(x),x)
}

And then, rollappy(a,1,f) and that didn't work. Can someone help please?

Thx
R


Jefferies archives and monitors outgoing and incoming e-mail. The contents of this email, including any attachments, are confidential to the ordinary user of the email address to which it was addressed. If you are not the addressee of this email you may not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. Since the confidentiality of Internet e-mail cannot be guaranteed, please do not include private or confidential information (such as account numbers) or instructions requiring your authorization (such as orders or funds transfers) in your e-mail communication to us. This email may be produced at the request of regulators or in connection with civil litigation. Jefferies accepts no liability for any errors or omissions arising as a result of transmission. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by Jefferies, its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. In the United Kingdom, Jefferies operates as Jefferies International Limited; registered in England: no. 1978621; and Jefferies Bache Limited; registered in England: no. 114226; registered office for both: Vintners Place, 68 Upper Thames Street, London EC4V 3BJ. Jefferies International Limited and Jefferies Bache Limited are authorised and regulated by the Financial Services Authority. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you.

	[[alternative HTML version deleted]]

