Dear helpers,
FYI, I am a beginner of R, just have dealt with MATLAB or JAVA.
I want to know how to solve one problem given 4 variables: year_1, year_2,
tall_1, tall_2.
The tall_1 is measured at year_1 and tall_2 at year_2.
The tall has grown up such as uniformly 1 cm/yr.
The data is like
year_1 year_2 tall_1 tall_2
2007 2010 12 15
1999 2009 6 16
2003 2005 11 13
2002 2009 3 10
. . . . .
. . . . .
. . . . .
. . . . .
So I need to get the average tall of the plant against year, for all the
years of available data.
The year_1 and year_2 are recorded so that a plant is alive if the year of a
question is equal to or grater than the year_1 and equal to and less than
the year_2.
For example,
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
2009 2010
6 7 8 9 10 11 12
13 14 15 16
3 4 5 6
7 8 9 10
11 12 13
12 13 14 15
avg
6 7 8 6 25/3 ...etc.
Since the amount of the data is too huge, I need to use appropriate
functions and algorithm but I am
not good at programming R.
I wish you help me out from this hell problem please.
Thanks,
Keeeeeeee
--
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On Feb 11, 2010, at 7:32 PM, Keeeeeeee wrote:> > Dear helpers, > > FYI, I am a beginner of R, just have dealt with MATLAB or JAVA. > > I want to know how to solve one problem given 4 variables: year_1, > year_2, > tall_1, tall_2. > The tall_1 is measured at year_1 and tall_2 at year_2. > The tall has grown up such as uniformly 1 cm/yr. > > The data is like > > year_1 year_2 tall_1 tall_2 > 2007 2010 12 15 > 1999 2009 6 16 > 2003 2005 11 13 > 2002 2009 3 10 > . . . . . > . . . . . > . . . . . > . . . . . > > So I need to get the average tall of the plant against year, for all > the > years of available data.For an individual plant, Wouldn't this just be (tall_2 + tall_1)/2? (Or if you wanted to do it the hard way then use seq and divide by number of years:) > dfp <- rd.txt("year_1 year_2 tall_1 tall_2 + 2007 2010 12 15 + 1999 2009 6 16 + 2003 2005 11 13 + 2002 2009 3 10") > dfp$plant.avg <- apply(dfp, 1, function(x) sum(seq(x[3], x[4]) ) / (x[2]-x[1]+1) ) > dfp year_1 year_2 tall_1 tall_2 plant.avg 1 2007 2010 12 15 13.5 2 1999 2009 6 16 11.0 3 2003 2005 11 13 12.0 4 2002 2009 3 10 6.5 > dfp$plant.avg2 <- apply(dfp, 1, function(x) (x[3]+ x[4] ) / 2 ) > dfp year_1 year_2 tall_1 tall_2 plant.avg plant.avg2 1 2007 2010 12 15 13.5 13.5 2 1999 2009 6 16 11.0 11.0 3 2003 2005 11 13 12.0 12.0 4 2002 2009 3 10 6.5 6.5 I don't think you need to create the display below if you want to answer the question posed. And if this happens to be homework, be sure that I get credit. -- David> The year_1 and year_2 are recorded so that a plant is alive if the > year of a > question is equal to or grater than the year_1 and equal to and less > than > the year_2. > > For example, > 1999 2000 2001 2002 2003 2004 2005 2006 > 2007 2008 > 2009 2010 > 6 7 8 9 10 11 12 > 13 14 15 16 > 3 4 > 5 6 > 7 8 9 10 > 11 12 13 > > 12 13 14 15 > > avg > 6 7 8 6 25/3 ...etc. > > Since the amount of the data is too huge, I need to use appropriate > functions and algorithm but I am > not good at programming R. > > I wish you help me out from this hell problem please. > > Thanks, > Keeeeeeee > > --David Winsemius, MD Heritage Laboratories West Hartford, CT
Take it easy. I wrote that thank you.
Actually, the sentences "Get the average tall of the plant against year,
for
all the years of available data.
The year_1 and year_2 are recorded so that a plant is alive if the year of a
question is equal to or grater than the year_1 and equal to and less than
the year_2. "
is just copied from the problem and that's all.
As well, the table I meant is just below
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
2009 2010
6 7 8 9 10 11 12
13 14 15 16
3 4 5 6
7 8 9 10
11 12 13
12 13 14 15
avg
6 7 8 6 25/3 ...etc.
Nevertheless, I am sorry if you couldn't understand what it means.
--
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