Combining Two Lists

*To*: mathgroup at smc.vnet.net*Subject*: [mg127023] Combining Two Lists*From*: Hershel Lackey <hhl089827 at gmail.com>*Date*: Sun, 24 Jun 2012 04:27:31 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hi, I'm having a little difficulty in combining two lists. These lists contain individual sets of data and then particular items within the set. On one list the first column is the set the data is in and the second column is the particular item, and this is followed by 5 properties of that item. The second list starts the same, where the first column is the set the data is in and the second column is the item, but instead of having the properties listed out in individual columns the data set repeats itself listing the properties A,B,C,D,E,F all in the same column. Below is a representative example of the two list. List 1 Data Set Item # Property 1 Property 2 Property 3 Property 4 Property 5 Q1 1 6.78 25.61 30.90 48.90 0.61 Q1 2 12.57 23.44 5.22 37.20 6.90 Q2 8 18.78 21.17 11.37 2.54 0.82 Q2 2 34.81 14.87 15.04 36.78 4.54 Q2 10 22.75 10.34 16.61 23.49 3.86 Q3 5 47.15 7.23 11.23 40.01 3.53 Q3 8 28.71 12.41 18.40 49.17 5.99 List 2 Data Set Item# Property 6 Measure % Q1 1 A 0 Q1 1 B 5 Q1 1 C 15 Q1 1 D 80 Q1 1 E 0 Q1 1 F 0 Q1 2 A 80 Q1 2 B 10 Q1 2 C 10 Q1 2 D 0 Q1 2 E 0 Q1 2 F 0 Q2 2 A 5 Q2 2 B 5 Q2 2 C 0 Q2 2 D 15 Q2 2 E 0 Q2 2 F 0 Q2 8 A 0 Q2 8 B 0 Q2 8 C 65 Q2 8 D 15 Q2 8 E 0 Q2 8 F 20 Q2 10 A 5 Q2 10 B 5 Q2 10 C 85 Q2 10 D 0 Q2 10 E 0 Q2 10 F 0 Q3 5 A 8 Q3 5 B 0 Q3 5 C 85 Q3 5 D 7 Q3 5 E 0 Q3 5 F 0 Q3 8 A 12 Q3 8 B 3 Q3 8 C 60 Q3 8 D 15 Q3 8 E 0 Q3 8 F 0 Note that the item # are repeat between different data sets, and data sets are different sizes. What I would like to do is combine the two lists matching the first two columns, to give groups like {Q1, 1, 6.7, 25.61, 30.90, 48.90, 0.61,{0,5,15,80,0,0}} for each individual. I have used Cases to identify matching data sets and item numbers in the two lists. It is then possible to append the two portions of the list to give part of the desired data set. However, this was laborious in typing in every data set and then item # into Cases, and impractical for large data sets. I'm sure there is a way to Map Cases or Select over the list, and append the appropriate data when data set and item # match, but I haven't figured out how to do that. Also it seems possible to use an if then statement; that if the data set and item # match then append, else move through the list. However, I haven't figured out how to code for this either. I appreciate any help. Thanks, Hershel

**Follow-Ups**:**Re: Combining Two Lists***From:*christopher arthur <chris.arthur1@gmail.com>