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Re: [mg5387] select a range of elements from a nested list
Posted:
Dec 6, 1996 11:27 PM


At 07:50 PM 12/5/96 +0000, you wrote: >Hi MathGroup > >Say you have a nested list like that {{x1,y1},{x2,y2},{x3,y3},...{xn,yn}} >basically containing X and Y values for a XY plot in each element. The X >values span a range from say 0 to 0.4 and you ONLY want to select the >elements (x,y values) from the list for which the x value spans say 0 to >0.3. BUT you don't want to COUNT the elements (visually on the screen) and >figure out the position at which the x value is just greater than 0.3 and >then subtract 1 from this position. > >I still want do define the list by using > >Table[list[[x,1]],list[[x,2]],{x, 1, ZZZ}] > >here ZZZ means the number for which the x value <= 0.3, this number needs >to be found by MATHEMATICA! > >I like to know if there is a general procedure to select elements from a >nested list based on the values of one member of the elements of that >nested list. > >I hope I made myself clear enough to you all. > >Thanks a lot. > >Oliver Schurr >Department of Chemistry >Georgetown University >Washington, DC 20057 > > Oliver,
Below is a 2.2.3 version of what you requested. Take a look, and try it.
I think it meets your specs. If you want a 3.0 version, I will be glad
to help. If you want modifications, send me a note. The last four lines
are simply a test of the package, and of course, can be deleted. If you
have other needs, I will be glad to consider them.
sincerely
Sherman C. Reed AT&TBell Laboratories (Lucent Technologies), retired Sr. Lecturer and grad advisor, UTAEE Department, retired



