question about RefRMA (RefPlus)
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@james-anderson-1641
Last seen 9.7 years ago
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@richard-friedman-513
Last seen 9.7 years ago
Jim, I am not acquainted with RefRMA but I have prepared Powerpoint slides explaining RMA and GCRMA at what I believe is an introductory level (it was also my way of explaining it to myself). I can send these to you under separate cover if these might help, or post them if there is general interest and if it is allowed. Best wishes, Rich On Feb 19, 2007, at 8:05 PM, James Anderson wrote: > Hi, > I think the rough idea of RefRMA is to use the training set cel > images to do RMA normalization, then we have a model how to map every > cel image to an intensity vector for training sample. For the cel > image file for test samples, apply the same mapping to get the > intensity for each test sample, based on the model obtained by RMA > normalization with training samples ONLY. My questions are: > > Could anybody explain to me EXACTLY what RMA does? I know > roughly what RMA does, but not clearly about the process of > converting cel image file to an intensity vector for each sample > Suppose my case is I have two sites (say, they are both affy > files, each site has 50 samples), I want to train the samples > measured at site 1 to classify the samples in site 2. Suppose > there are some obvious systematic difference between the two > sites, for example, site 1 is measured with much brighter light > than sight 2, so that the image of site 2 files are always dimmer > than site 1. Does RefRMA (or RefPlus) account for this (systematic > bias) when normalizing each sample in test site 2 to test site 1? > > Thank you very much! > > James > > > --------------------------------- > We won't tell. Get more on shows you hate to love > > [[alternative HTML version deleted]] > > _______________________________________________ > Bioconductor mailing list > Bioconductor at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: > http://news.gmane.org/gmane.science.biology.informatics.conductor > ------------------------------------------------------------ Richard A. Friedman, PhD Associate Research Scientist Herbert Irving Comprehensive Cancer Center Oncoinformatics Core Lecturer Department of Biomedical Informatics Box 95, Room 130BB or P&S 1-420C Columbia University Medical Center 630 W. 168th St. New York, NY 10032 (212)305-6901 (5-6901) (voice) friedman at cancercenter.columbia.edu http://cancercenter.columbia.edu/~friedman/ "My story has a hundred characters and it takes place over a year. When I finish it, if it is shorter than Ulysses, then Joyce described things too much". -Rose Friedman, age 9
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Hi Rich, I am also interested in your Powerpoint slides. Could you send them to me or post them. Thanks, Shirley, On 2/20/07, Richard Friedman <friedman at="" cancercenter.columbia.edu=""> wrote: > Jim, > > I am not acquainted with RefRMA but I have prepared Powerpoint slides > explaining > RMA and GCRMA at what I believe is an introductory level (it was also > my way of explaining > it to myself). I can send these to you under separate cover if these > might help, or post them > if there is general interest and if it is allowed. > > Best wishes, > Rich > > On Feb 19, 2007, at 8:05 PM, James Anderson wrote: > > > Hi, > > I think the rough idea of RefRMA is to use the training set cel > > images to do RMA normalization, then we have a model how to map every > > cel image to an intensity vector for training sample. For the cel > > image file for test samples, apply the same mapping to get the > > intensity for each test sample, based on the model obtained by RMA > > normalization with training samples ONLY. My questions are: > > > > Could anybody explain to me EXACTLY what RMA does? I know > > roughly what RMA does, but not clearly about the process of > > converting cel image file to an intensity vector for each sample > > Suppose my case is I have two sites (say, they are both affy > > files, each site has 50 samples), I want to train the samples > > measured at site 1 to classify the samples in site 2. Suppose > > there are some obvious systematic difference between the two > > sites, for example, site 1 is measured with much brighter light > > than sight 2, so that the image of site 2 files are always dimmer > > than site 1. Does RefRMA (or RefPlus) account for this (systematic > > bias) when normalizing each sample in test site 2 to test site 1? > > > > Thank you very much! > > > > James > > > > > > --------------------------------- > > We won't tell. Get more on shows you hate to love > > > > [[alternative HTML version deleted]] > > > > _______________________________________________ > > Bioconductor mailing list > > Bioconductor at stat.math.ethz.ch > > https://stat.ethz.ch/mailman/listinfo/bioconductor > > Search the archives: > > http://news.gmane.org/gmane.science.biology.informatics.conductor > > > ------------------------------------------------------------ > Richard A. Friedman, PhD > Associate Research Scientist > Herbert Irving Comprehensive Cancer Center > Oncoinformatics Core > Lecturer > Department of Biomedical Informatics > Box 95, Room 130BB or P&S 1-420C > Columbia University Medical Center > 630 W. 168th St. > New York, NY 10032 > (212)305-6901 (5-6901) (voice) > friedman at cancercenter.columbia.edu > http://cancercenter.columbia.edu/~friedman/ > > "My story has a hundred characters and it takes place over a year. > When I finish it, if it is shorter than Ulysses, then Joyce described > things > too much". > -Rose Friedman, age 9 > > _______________________________________________ > Bioconductor mailing list > Bioconductor at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor >
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