[R] Case study in forensic computing domain
Hi, I am looking for case studies, possibly real world, in forensic domain that will entice forensic computing students and demonstrate the usefulness of machine learning in forensics. Does anyone know of any such case studies? Students should be able to replicate the case study, so it should have some public corpus data and R code to implement the machine learning approach. I think a case study to determine the authorship of document using machine learning would be good. The other case study could a regression model to detect fake currency based on size, weight and other attributes of a note. Any pointers would be welcome. Thanks, Ambi. [[alternative HTML version deleted]] __ R-help@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.
[R] Fwd: Using R for Multiple Regression
-- Forwarded message -- From: Ambikesh Jayal ambi1...@gmail.com Date: Sun, Aug 1, 2010 at 2:24 PM Subject: Re: [R] Using R for Multiple Regression To: ted.hard...@manchester.ac.uk Hi Ted, Thanks to all those who have replied. It was very helpful. As there can be multiple solutions, is there a way in R to show all the possible models for a dataset? Also in R the value of coefficient of an independent variable being shown as NA is same as being shown as 0 (implying that this variable does not count). However, in trying it out as you have, you have already found out something very important about linear regression! (And about R). The important point being that there can be multiple equations describing a dataset? Or one way to simplify a model is to remove the independent variables that depend on other independent variables? Thanks again. Kind regards Ambikesh Jayal, Department of Information Systems, Computing and Mathematics Room 134 St John's Building Brunel University Uxbridge, Middlesex UB8 3PH, UK Website: http://sites.google.com/site/ambi1999/ On Fri, Jul 30, 2010 at 5:59 PM, Ted Harding ted.hard...@manchester.ac.ukwrote: On 30-Jul-10 15:07:46, Ambikesh Jayal wrote: Hi, Subject: Using R for Multiple Regression I am new to statistic but am interested in applying mathematical models to solve biological problems. I have used a linear model to generate the test data. When using this data I expect R to correctly identify the model but that does not seem to be the case. I am certain that I am doing something wrong but not able to figure it out. Model: Y = m1x1 + m2x2+ m3X3 + c Model Identified by R using lm(formula = y ~ x1 + x2 + x3) (Intercept) 8.000e+01 x1 1.100e+01 x2 NA x3 NA The data I am using is as follows: y x1 x2 x3 91 1 14 2 102 2 15 5 113 3 16 8 124 4 17 11 135 5 18 14 146 6 19 17 157 7 20 20 168 8 21 23 179 9 22 26 190 10 23 29 Kind regards Dr. Ambikesh Jayal, You should look again at your data! You have x2 = 13 + x1, x3 = 3*x1 - 1 in these data. Hence your model Y = m1*x1 + m2*x2+ m3*X3 + c with m1=5, m2=6, m3=0, c=2 is the same as Y = 5*x1 + 6*(x1+13) + 0*(3*x1 - 1) + 2 = 11*x1 + 6*13 + 2 = 11*x1 + 80 and R has found that the coefficient of x1 is 1.100e+01 = 11, and that the intercept is 8.000e+01 = 80, and has also identified that, after allowing for x1, x2 and x3 are irrelevant. So, to try out how R behaves in linear regression, you should use data which do not have this property that some of the independent variables (x1,x2,x3) are linear functions of the others. However, in trying it out as you have, you have already found out something very important about linear regression! (And about R). Hoping this helps, Ted. E-Mail: (Ted Harding) ted.hard...@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 30-Jul-10 Time: 17:59:51 -- XFMail -- [[alternative HTML version deleted]] __ R-help@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.
[R] Using R for Multiple Regression
Hi, Subject: Using R for Multiple Regression I am new to statistic but am interested in applying mathematical models to solve biological problems. I have used a linear model to generate the test data. When using this data I expect R to correctly identify the model but that does not seem to be the case. I am certain that I am doing something wrong but not able to figure it out. Model: Y = m1x1 + m2x2+ m3X3 + c m1=5 m2=6 m3=0 c=2 Model Identified by R using lm(formula = y ~ x1 + x2 + x3) (Intercept) 8.000e+01 x1 1.100e+01 x2 NA x3 NA The data I am using is as follows: y x1 x2 x3 91 1 14 2 102 2 15 5 113 3 16 8 124 4 17 11 135 5 18 14 146 6 19 17 157 7 20 20 168 8 21 23 179 9 22 26 190 10 23 29 Kind regards Dr. Ambikesh Jayal, Department of Information Systems, Computing and Mathematics Room 134 St John's Building Brunel University Uxbridge, Middlesex UB8 3PH, UK Website: http://sites.google.com/site/ambi1999/ [[alternative HTML version deleted]] __ R-help@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.
[R] R to solve search problems
Hi All, I am new to R and want to use R to solve search problems (like Travelling salesman problem, finding nearest neighbour, hill climbing). Is this possible in R? To start with I want as follows. Find five float numbers whose sum is is equal to their product which should be 8000. x + y + z + p + r = 8000 x * y * z * p * r = 8000 Regards, Ambikesh Jayal. School of IS, Computing Maths, Brunel University, Uxbridge, UB8 3PH, United Kingdom. Email: ambi1...@gmail.com [[alternative HTML version deleted]] __ R-help@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.
[R] Using R to solve search problems
Hi All, I am new to R and want to use R to solve search problems (like Traveling salesman problem, finding nearest neighbor, hill climbing). Is this possible in R? To start with I want as follows. Find five float numbers whose sum is is equal to their product which should be 8000. x + y + z + p + r = 8000 x * y * z * p * r = 8000 Regards, Ambikesh Jayal. School of IS, Computing Maths, Brunel University, Uxbridge, UB8 3PH, United Kingdom. Email: ambi1...@gmail.com [[alternative HTML version deleted]] __ R-help@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.
