[R] Help regarding removing Inf from dataframe, creating new dataframe with selected variables, count function

[makhija.sangeeta at gmail.com]

Following is my query: 
1. Removing Inf from one column of dataframe.
2. out of 10 available dates, count how many times a security is present. (repeat for each security)
3. Out of dates, the security is present, I want to read latest status of market cap.
4. Change in market cap represent by 0/1 so even if market cap status changed once, take value 1.
5. create output file containing some already existed variables and newly created variables.
following is sample data:
Date	AssetId	Name	Country	Liquidity	MCName
2006_12_31	322833	YPF 'D'	Argentina	1	LC
2006_12_31	321948	TELECOM ARGN.'B'	Argentina	1	LC
2006_12_31	320205	TELEFONICA DE ARGN.'B'	Argentina	1	LC
2007_12_31	874140	YPF 'D'	Argentina	1	LC
2006_12_31	281678	PETROBRAS ENGA.PPC.'B'	Argentina	1	LC
2006_12_31	992260	PETROBRAS ENERGIA 'B'	Argentina	1	LC
2007_12_31	320148	TELECOM ARGN.'B'	Argentina	1	MC
2006_12_31	131879	BANCO MACRO 'B'	Argentina	1	MC
2008_12_31	677693	YPF 'D'	Argentina	1	MC
2006_12_31	149482	TSPA.GAS DEL SUR 'B'	Argentina	1	MC
2008_12_31	696138	TELECOM ARGN.'B'	Argentina	1	MC
2006_12_31	298819	GRUPO FINO.GALICIA 'B'	Argentina	1	MC
2006_12_31	982990	BANCO GALICIA 'B'	Argentina	0	SC
2006_12_31	322661	IRSA 'B'	Argentina	1	SC
2006_12_31	992128	INDUPA 'B'	Argentina	1	SC
2006_12_31	320053	BBVA BANCO FRANCES 'B'	Argentina	1	SC
2006_12_31	992183	MOLINOS RIO PLATA 'B'	Argentina	1	SC
2006_12_31	320096	MINETTI(J) 'B'	Argentina	1	SC
2006_12_31	322656	PAMPA ENERGIA	Argentina	0	SC
2006_12_31	982902	CRESUD 'B'	Argentina	1	SC
2006_12_31	992156	LEDESMA 'B'	Argentina	1	SC
2006_12_31	265532	TRANSENER 'B'	Argentina	1	SC
2006_12_31	982616	ACINDAR 'B' DEAD - DELIST.29/01/09	Argentina	1	SC
2006_12_31	884387	ALTO PALERMO 'B'	Argentina	0	SC
2006_12_31	134841	METROGAS 'B'	Argentina	1	SC
2006_12_31	992126	IMPORT&EXPORT PATAG.'B'	Argentina	0	SC
2006_12_31	677414	GAS NATURAL 'B'	Argentina	1	SC
2006_12_31	151203	CAPEX 'A'	Argentina	1	SC
2006_12_31	322652	BOLDT 'B'	Argentina	1	SC
2006_12_31	255169	CAMUZZI GAS PAMPEANA 'B'	Argentina	1	SC
2006_12_31	134627	ENDESA COSTANERA 'B'	Argentina	1	SC
2006_12_31	134645	CENTRAL PUERTO 'B'	Argentina	1	SC
2006_12_31	320158	CELULOSA 'B'	Argentina	1	SC
2006_12_31	982620	ALPARGATAS	Argentina	1	SC
2006_12_31	982904	RIGOLLEAU 'B'	Argentina	1	SC
2006_12_31	689402	SAN LORENZO 'B'	Argentina	1	SC
2006_12_31	982655	CARLOS CASADO 'B'	Argentina	1	SC
2006_12_31	982933	FERRUM 'B'	Argentina	0	SC
2006_12_31	286752	DISB.DE GAS CUYANA 'B'	Argentina	1	SC
2006_12_31	151196	MIRGOR 'C'	Argentina	1	SC
2006_12_31	50923T	TSPA.DE GS.DEL NORTE 'C'	Argentina	0	SC
2006_12_31	286047	GPO.CONCIO.DEL OESTE 'B'	Argentina	0	SC
2006_12_31	322664	CARBOCLOR 'B'	Argentina	1	SC