joint find statement using ismember & ~ismember

Hi,

I wrote the following code: xe=find(ismember(ID,IDA) & ~ismember(DateID,DateIDA)); but it is failing to capture what I want I want to find the observations where the IDs matches (i,e the ids in the ID column exist in the IDA column but the dates respective of the ID column don't exist in the dates respective to IDA column) example: ID=[ 1;2;....20]; IDA=[1;2;....40]; DateID=[729115;729206;.....729298] DateIDA=[729115;733393;.....729298]

what i want xe to find is that for ID=2 & date=729206 I don't have an IDA=2 with a date=729206. I would appreciate any help in this joint find statement

Answer 1

[Stephen23]

It works fine for me, using your sample data:

>> ID = [1;2;20];
>> IDA = [1;2;40];
>> DateID = [729115;729206;729298];
>> DateIDA = [729115;733393;729298];
>> ismember(ID,IDA) & ~ismember(DateID,DateIDA)
ans =
     0
     1
     0

You might need to round your date numbers to integer before making this comparison.