Hello R-help
I have the following data for a standard curve
concentration(nM),fluorescence
0,48.34
2,58.69
5,70.83
10,94.73
20,190.8
50,436.0
100, 957.9
(1)Is there function in R to plot a spline.
(2)How can I interpolation,say 1000 point from 0nM-100nM and store this as a
data frame of concentration,fluorescence
(3)How can I modify the code below so that instead of retrieving a concentration
with the exact value of fluorescence, it gives me concentration for the value
that is closest to that fluorescence.
subset(df,fluorescence==200.3456,select=concentration)
[[alternative HTML version deleted]]
On Feb 5, 2011, at 9:29 AM, Asan Ramzan wrote:> Hello R-help > I have the following data for a standard curve > concentration(nM),fluorescence > 0,48.34 > 2,58.69 > 5,70.83 > 10,94.73 > 20,190.8 > 50,436.0 > 100, 957.9 > > (1)Is there function in R to plot a spline.?spline> (2)How can I interpolation,say 1000 point from 0nM-100nM and store > this as a > data frame of concentration,fluorescence?approxfun> (3)How can I modify the code below so that instead of retrieving a > concentration > with the exact value of fluorescence, it gives me concentration for > the value > that is closest to that fluorescence.?which.min #(although I would be using "[" rather than subset for that purpose.)> > subset(df,fluorescence==200.3456,select=concentration) > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.David Winsemius, MD West Hartford, CT
Also ?splinefun (like approxfun but using splines instead of lines). -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.snow at imail.org 801.408.8111> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of David Winsemius > Sent: Saturday, February 05, 2011 8:24 AM > To: Asan Ramzan > Cc: r-help at r-project.org > Subject: Re: [R] spline interpolation > > > On Feb 5, 2011, at 9:29 AM, Asan Ramzan wrote: > > > Hello R-help > > I have the following data for a standard curve > > concentration(nM),fluorescence > > 0,48.34 > > 2,58.69 > > 5,70.83 > > 10,94.73 > > 20,190.8 > > 50,436.0 > > 100, 957.9 > > > > (1)Is there function in R to plot a spline. > > ?spline > > > (2)How can I interpolation,say 1000 point from 0nM-100nM and store > > this as a > > data frame of concentration,fluorescence > > ?approxfun > > > (3)How can I modify the code below so that instead of retrieving a > > concentration > > with the exact value of fluorescence, it gives me concentration for > > the value > > that is closest to that fluorescence. > > ?which.min #(although I would be using "[" rather than subset for > that purpose.) > > > > > subset(df,fluorescence==200.3456,select=concentration) > > > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help at r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > > and provide commented, minimal, self-contained, reproducible code. > > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code.
Hi, Just pure curiosity: may I ask why you want to do spline interplation on fluorescence intensity as function of concentration? Particularly as it looks quite typical for an unknown problem's calibration plot? Claudia On 02/05/2011 03:29 PM, Asan Ramzan wrote:> Hello R-help > I have the following data for a standard curve > concentration(nM),fluorescence > 0,48.34 > 2,58.69 > 5,70.83 > 10,94.73 > 20,190.8 > 50,436.0 > 100,?957.9 > ? > (1)Is there function in R?to plot a spline. > (2)How can I interpolation,say 1000 point from 0nM-100nM and store this as a > data frame of concentration,fluorescence > (3)How can I modify?the code below so that instead of retrieving a concentration > with the exact value of fluorescence, it gives me concentration for the value > that is closest to that fluorescence. > ? > subset(df,fluorescence==200.3456,select=concentration) > > > > [[alternative HTML version deleted]] > > > > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.-- Claudia Beleites Dipartimento dei Materiali e delle Risorse Naturali Universit? degli Studi di Trieste Via Alfonso Valerio 6/a I-34127 Trieste phone: +39 0 40 5 58-37 68 email: cbeleites at units.it