[R] How to apply apply?!

Raghuraman Ramachandran
2010-08-06T19:06:24Z

guRus

I have say a dataframe, d and I wish to do the following:

1) For each row, I want to take one particular value of the row and multiply
it by 2. How do I do it. Say the data frame is as below:
   OPEN HIGH LOW CLOSE 1931.2 1931.2 1931.2 1931.2 0 0 0 999.05 0 0 0 1052.5
0 0 0 987.8 0 0 0 925.6 0 0 0 866 0 0 0 1400.2 0 0 0 754.5 0 0 0 702.6 0 0 0
653.25 0 0 0 348 0 0 0 801 866.55 866.55 866.55 866.55 783.1 783.1 742.25
742.25 575 575 575 575 0 0 0 493 470 470 420 425 355 360 343 360 312.05
312.05 274 280.85 257.35 257.35 197 198.75 182 185.95 137 150.75 120.25 129
90.7 101.25 91.85 91.85 57 66.6

How do I multiply only the close of every row using the 'apply'
function?
And once multiplied how do I obtain a new table that also contains the new
2*CLOSE column (without cbind?).

2) Also, how do I run a generic function per row. Say for example I want to
calculate the Implied Volatility for each row of this data frame ( using the
RMterics package). How do I do that please using the apply function? I am
focusing on apply because I like the vectorisation concept in R and I do not
want to use a for loop etc.

Many thanks for the enlightment,
Raghu

	[[alternative HTML version deleted]]