[R] Basic structure operations doubt

Santosh Srinivas santosh.srinivas at gmail.com
Mon Oct 18 04:06:32 CEST 2010


I'm doing these manipulations on the data frame and wondering why does R
have to remember historical data on my operation and not just keep the
needed info.
Probably a basic fundamentals of the way R handles data .. Pls point me to
the manual if possible ..

I have this Index data:
> head(NIFTY_INDX)
  Constituents.list.of.S.P.CNX.Nifty                          X       X.1
X.2          X.3
1

2                       Company Name                   Industry    Symbol
Series    ISIN Code
3

4                           ACC Ltd. CEMENT AND CEMENT PRODUCTS       ACC
EQ INE012A01025
5                Ambuja Cements Ltd. CEMENT AND CEMENT PRODUCTS AMBUJACEM
EQ INE079A01024
6                     Axis Bank Ltd.                      BANKS  AXISBANK
EQ INE238A01026


I Import the section that is relevant to me:

> Indx_Constituents <- NIFTY_INDX[4:NROW(NIFTY_INDX),]
> head(Indx_Constituents)
  Constituents.list.of.S.P.CNX.Nifty                              X
X.1 X.2          X.3
4                           ACC Ltd.     CEMENT AND CEMENT PRODUCTS
ACC  EQ INE012A01025
5                Ambuja Cements Ltd.     CEMENT AND CEMENT PRODUCTS
AMBUJACEM  EQ INE079A01024
6                     Axis Bank Ltd.                          BANKS
AXISBANK  EQ INE238A01026
7                    Bajaj Auto Ltd. AUTOMOBILES - 2 AND 3 WHEELERS
BAJAJ-AUTO  EQ INE917I01010
8      Bharat Heavy Electricals Ltd.           ELECTRICAL EQUIPMENT
BHEL  EQ INE257A01018
9  Bharat Petroleum Corporation Ltd.                     REFINERIES
BPCL  EQ INE029A01011


> colNames <- NIFTY_INDX[2,]
> colNames
  Constituents.list.of.S.P.CNX.Nifty        X    X.1    X.2       X.3
2                       Company Name Industry Symbol Series ISIN Code


I want to assign the info from colNames[1,] to Indx_Constituents .... I am
unable to do this directly ... I can probably pull out the values and do it
but there should be an easier way


Now when I do this:
> colNames[1,1]
[1] Company Name
52 Levels:  ACC Ltd. Ambuja Cements Ltd. Axis Bank Ltd. Bajaj Auto Ltd.
Bharat Heavy Electricals Ltd. Bharat Petroleum Corporation Ltd. Bharti
Airtel Ltd. Cairn India Ltd. Cipla Ltd. Company Name ... Wipro Ltd.

Why does R have to remember the 52 levels?? Why can't it just have the
relevant data stored
What are the alternatives so that I can simply have my needed data in my
data frames?

Thanks for your explanation.


----------------------------------------------------------------------------
--------------------------
Thanks R-Helpers. Yes, this is a silly question and it will not be repeated!
:-)



More information about the R-help mailing list