addATR() and addTA(ATR()) generate different plots
On Thu, Nov 28, 2013 at 10:00 AM, <manojit_roy at comcast.net> wrote:
Thanks for the prompt response. Adding HLC() to ATR() function brings the plot closer to the addATR() plot, but there are still differences - addATR() values are somewhat higher than addTA(ATR) values, and the two plots differ in shape too.
The default arguments are different:
args(addATR)
function (n = 14, maType = "EMA", ...) NULL
args(ATR)
function (HLC, n = 14, maType, ...) NULL So try: addTA(ATR(HLC(ticker),n=20,maType="EMA")$atr,col='blue',lwd=2) Please keep replies on-list, so everyone can benefit from the discussion. Best, -- Joshua Ulrich | about.me/joshuaulrich FOSS Trading | www.fosstrading.com
________________________________
From: "Joshua Ulrich" <josh.m.ulrich at gmail.com>
To: "manojit roy" <manojit_roy at comcast.net>
Cc: "r-sig-finance" <r-sig-finance at r-project.org>
Sent: Thursday, November 28, 2013 10:38:00 AM
Subject: Re: [R-SIG-Finance] addATR() and addTA(ATR()) generate different
plots
On Thu, Nov 28, 2013 at 9:33 AM, <manojit_roy at comcast.net> wrote:
I get different plots for ATR() when adding this indicator to my chart in
two different ways (see last 2 lines of the code below):
require(quantmod)
getSymbols('GTAT')
ticker <- last(GTAT,'5 years')
barChart(ticker,TA=NULL,theme='white',major.ticks='months',minor.ticks=FALSE,show.grid=FALSE)
plot(addATR(n=20))
plot(addTA(ATR(ticker,n=20)$atr,col='blue',lwd=2))
Can someone help me understand what I am doing wrong, and which ATR values
I should use?
ATR requires a HLC object. You're passing an OHLCV object to it. Try:
plot(addTA(ATR(HLC(ticker),n=20)$atr,col='blue',lwd=2))
TTR can't use the HLC function because HLC is in quantmod and quantmod
depends on TTR. So, for the time being, you have to be thoughtful
about the columns in the object you pass to TTR functions.
Best,
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com