conditionalFilter

conditionalFilter(X, condition, filterMap)

X is a scalar/vector.

condition is a scalar or a vector of the same length as X.

filterMap is a dictionary indicating the filtering conditions.

Return true if both of the following conditions are satisfied, otherwise return false.

• An element in the vector condition is a key to the dictionary filterMap;

• The corresponding element in X is one of the elements of the key's value in the dictionary filterMap.

If both X and condition are vectors, the result is a vector of the same length as X.

Example 1

conditionalFilter(1 2 3,`a`b`c, dict(`a`b,1 2));
// output
[1,1,0]

conditionalFilter(1 2 3,`a`b`b, dict(`a`b,[1 2,3 4]))
// output
[1,0,1]

Example 2. Get the specified stock data of the specified dates from table t:

2012.06.01: C, MS 2012.06.02: IBM, MS 2012.06.03: MS 2012.06.04: IBM

sym = `C`MS`MS`MS`IBM`IBM`C`C`C$SYMBOL
date = 2012.06.01 2012.06.01 2012.06.02 2012.06.03 2012.06.01 2012.06.02 2012.06.02 2012.06.03 2012.06.04
price = 49.6 29.46 29.52 30.02 174.97 175.23 50.76 50.32 51.29
qty = 2200 1900 2100 3200 6800 5400 1300 2500 8800
t = table(sym, date, price, qty)
t;

filter = dict(2012.06.01..2012.06.04, [`C`MS, `IBM`MS, `MS, `IBM])
select * from t where conditionalFilter(sym, date, filter) order by date, sym;

Example 3. The values of filterMap can also be pairs:

t=table(`aaa`aaa`bbb`bbb as id, 2020.09.03 2020.09.10 2020.09.06 2020.09.09 as date)
t

mydict = dict(`aaa`bbb, [2020.09.01 : 2020.09.09,  2020.09.05 : 2020.09.09])
select * from t where conditionalFilter(date, id, mydict);