Changeset 6141 for trunk/HELP_SOURCE/oldhelp/awt_csp.hlp
- Timestamp:
- 14/08/09 16:29:27 (3 years ago)
- Files:
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- 1 modified
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trunk/HELP_SOURCE/oldhelp/awt_csp.hlp (modified) (5 diffs)
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trunk/HELP_SOURCE/oldhelp/awt_csp.hlp
r2986 r6141 9 9 10 10 #************* Title of helpfile !! and start of real helpfile strunk******** 11 TITLE Estimate Parameters from Col oumn Statistics11 TITLE Estimate Parameters from Column Statistics 12 12 13 13 OCCURRENCE ARB_DIST 14 14 15 DESCRIPTION In a standar tRNA, base frequencies are not equally15 DESCRIPTION In a standard RNA, base frequencies are not equally 16 16 distributed. Especially in the archea subclass we find 17 17 extremely G+C rich sequences. … … 26 26 parts have a significant higher G+C content than non 27 27 helical parts. 28 One strait forward algor hythm would calculate each frequency29 independently for each col oumn.28 One strait forward algorithm would calculate each frequency 29 independently for each column. 30 30 Especially for small datasets the resulting frequencies would 31 31 look like random data, as too few examples are analyzed. … … 33 33 In ARB we implemented a combination of the 2 approaches. 34 34 Lets say we want to estimate a Parameter 'P' with 35 a maximum variance 'maxvar', so we need a min umum35 a maximum variance 'maxvar', so we need a minimum 36 36 samples 'minsap'. 37 37 … … 45 45 minimum of independent events. 46 46 47 - The final parameter estimate for a col oumn is a47 - The final parameter estimate for a column is a 48 48 weighted sum between the estimate for the 49 49 cluster and the estimate for the single position. 50 50 51 You can give your favo urite method a higher weight by52 controlling the smo thing parameter:51 You can give your favorite method a higher weight by 52 controlling the smoothing parameter: 53 53 54 54 Less smoothing -> independent parameter estimates … … 71 71 72 72 1. Much smoothing of parameters is selected and 73 2. you r are anlazing ribosomal RNA and73 2. you are analyzing ribosomal RNA and 74 74 3. 'Use Helix Information' is turned off 75 75
