Dear Yong The simplest approach would be to calculate a phi value for each stream, and then apply conventional anova.
There is some background on phi here: http://en.wikipedia.org/wiki/Particle_size_%28grain_size%29 There is an example of a simple algorithm to calculate phi from discrete categories here (Appendix E), this may need modifying slightly for your categories: http://www.wfduk.org/bio_assessment/bio_assessment/rivers_invertebrates regards Mike -----Original Message----- From: r-sig-ecology-boun...@r-project.org [mailto:r-sig-ecology-boun...@r-project.org] On Behalf Of Yong Zhang Sent: 12 January 2011 05:42 To: r-sig-ecology Subject: [R-sig-eco] What statistical analysis should I take?? Hello all, Now, I have a big trouble, thing is like that I sampled the sediment of 10 streams. These streams can be divided into two groups, group A and B , each group contains 5 streams. The sediment also can be divided into 4 types (according to the diameter of the sediment particle :sand < 2mm, gravel 2--64mm, cobble 64---256mm and boulder >256mm), I measured 100 sediment particles per stream, and the number of each kind sediment particle has been recorded. My sediment datas are something like: group A: sand gravel cobble boulder 1 10 20 20 50 2 20 30 20 30 3 ........etc.... 4 5 B: sand gravel cobble boulder 1 0 5 80 15 2 10 20 15 55 3 ...........etc............ 4 5 I aim to explore whether the sediment composition is significantly different between the two groups, or not. Could anyone tell me what analysi should I take, and any of your hint or suggestion will be greatly appreciated. All the best, Yong ps: If anyone have any idea, please tell me in details, because I am green. Thanks very much for your time! 2011-01-12 Yong Zhang, Ph.D. Lab of aquatic insects & stream ecology Dept.of Entonology, Nanjing Agricultural University Nanjing, 210095,China Phone number: (+86) -25-84395241 E-mail:2010202...@njau.edu.cn -- This message (and any attachments) is for the recipient only NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
