Delete problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg52871] Delete problem*From*: Todd Allen <genesplicer28 at yahoo.com>*Date*: Wed, 15 Dec 2004 04:26:54 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi everyone, I have situation where I am trying to quality control check a "list of lists" for certain values that should be deleted from the list if they are found. I have wrote a few lines of code that I believe should work, but rather than simply deleting a part of the list, mathematica seems to delete the entire list. Below is the situation with a small test dataset: masterlist={{{AEST-01-C-10,1,1,1,2,31,1,C,-2.14},{AEST-01-C-10,1,1,1,4,31,1, C,-1.1},{AEST-01-C-10,2,2,1,2,12,2,C,1.79}},{{AEST-07-E-04,2,1,2,1,10,2, C,1.334},{AEST-07-E-04,2,1,3,2,1,4,C,1.997},{AEST-07-E-04,3,2,1,1,2,1, C,-1.17},{AEST-07-E-04,3,4,1,1,21,2,C,2.15}}}; index=1;ccheck=Sign[masterlist[[index,All,9]]];While[ index<=Length[masterlist], If[Count[ccheck,_?Positive]>0 && Count[ccheck,_?Negative]>0 && Count[ccheck,_Integer]==3,masterlist=Delete[masterlist,index],index++]]; I am trying to delete lists that have both positive and negative values in the ninth position of common elements and also have only 3 members of that group. For example, I would expect mathematica to delete the first group of masterlist above, because it has three subgroups of AEST-01-C-10 and it has the values of -2.14, -1.1and 1.79 in each of the three AEST-01-C-10 elements. Sorry if I have badgered the proper use of list/grouping terminology, but hopefully my general idea is clear. Thank you for any thoughts you might have. Best regards, Todd __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail

**Follow-Ups**:**Re: Delete problem***From:*DrBob <drbob@bigfoot.com>

**Re: Delete problem***From:*Tomas Garza <tgarza01@prodigy.net.mx>

**Re: Delete problem***From:*William K Reinholtz <kirk.reinholtz@jpl.nasa.gov>