adjustOHLC discrepancy

Dear List:

I expect that use.Adjusted=TRUE or FALSE wouldn't affect the adjusted
close.  But running the following code proved I was wrong.

getSymbols('C',src='yahoo')

[1] "C"

head(adjustOHLC(C))

             C.Open   C.High    C.Low  C.Close C.Volume C.Adjusted
2007-01-03 190.8698 192.9960 187.6464 189.4639  2282100     498.66
2007-01-04 189.4639 192.5502 187.6464 188.8123  1658700     496.94
2007-01-05 188.6066 188.7780 186.7548 187.8179  1317900     494.32
2007-01-08 187.2349 189.1210 186.2061 188.7780  1236900     496.85
2007-01-09 188.6409 189.1210 185.8289 187.1320  1963000     492.52
2007-01-10 186.1032 186.8577 185.0059 185.6232  1744900     488.55

head(adjustOHLC(C,use.Adjusted=TRUE))

             C.Open   C.High    C.Low C.Close C.Volume C.Adjusted
2007-01-03 502.3605 507.9563 493.8765  498.66  2282100     498.66
2007-01-04 498.6548 506.7777 493.8714  496.94  1658700     496.94
2007-01-05 496.3958 496.8471 491.5221  494.32  1317900     494.32
2007-01-08 492.7886 497.7525 490.0809  496.85  1236900     496.85
2007-01-09 496.4912 497.7548 489.0903  492.52  1963000     492.52
2007-01-10 489.8136 491.7992 486.9254  488.55  1744900     488.55

by using adjustOHLC, the C.close value is not the same as C.Adjusted
provided directly by yahoo.
             C.Open   C.High    C.Low  C.Close C.Volume C.Adjusted
2007-01-03 190.8698 192.9960 187.6464 189.4639  2282100     498.66

I think adjustOHLC and adjRatios are theoretically correct and  I
wonder where this discrepancy comes from. Is it possible Yahoo uses a
different method to calculate its adjusted close.

Which adjusted close would everyone recommend? the raw close adjusted
by adjustOHLC or the adjusted close provided by yahoo?

Thanks!
Jim.

I hope that helps a bit, though I realize I probably created more
questions for you than I answered.

Thanks Josh. I'll dig a little more with your clues and post back if I
find anything.

Jim.

library(quantmod) # requires TTR
getSymbols("INFY.BO")

head(ATR(INFY.BO))

Why not use the ATR indicator in the TTR package?

On Thu, Sep 20, 2012 at 11:39 AM, sean fallon <sf99167 at yahoo.com> wrote:

I am trying to calculate the Absolute value to append in file so I can
build ATR indicator. I am stuck at the first part wherein I am trying to
calculate the ABS for High - Close Price. However when I run the
"head(data)" to see what the results are, the AbsHC shows me the same
number i.e. 61.2, whether I put the "data$AbsHC=abs(x)" inside the for loop
or outside. I am only trying it for the first 10 rows of data. Enclosed
below is the code

#Get data fro Yahoo finance for Infosys (INFY.BO)
data <- read.csv("
http://ichart.finance.yahoo.com/table.csv?s=INFY.BO&a=08&b=16&c=2008&d=08&e=20&f=2012&g=d&ignore=.csv",
stringsAsFactors=F)

#view data
head(data)

#compute high-close
h=data[,3]
c=data[,4]
hcdif=h-c
data$HminusC=hcdif

#check data
data[30:40,]

#compute absolute value
j=2
for (i in 1:10)
{
   ab1= data[i,5]
   ab2= data[j,3]
   x=ab1-ab2
   #data$AbsHC=abs(x), I have commented this as I have out it outside the
loop.
   j = j+1
}

data$AbsHC=abs(x)
head(data)

What am I doing wrong here???

regards

Sean
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