SAS - Find value in lookup table that is the minimum distance above your value

SAS_find_nearest neighbour above value.sas

/*This finds the nearest value ABOVE a set value, it could be modified to find the lowest or nearest in general
Originally propsed here via F. Khurshed
https://communities.sas.com/t5/SAS-Programming/Finding-Closest-Value-to-a-List-of-Values/m-p/498539
*/

data t1;
input value1;
cards;
31
53
25
125
129
;

data t2;
input value2;
cards;
31
62
93
124
155
;
run;

data find_nearest;
*load data into temporary array;
array _nearest(5) _temporary_;

if _n_=1 then do j=1 to dim(_nearest);
    set T2;*dataset with values to load into array;
    _nearest(j) = value2;
end;

call sortn(of _nearest(*));

set T1;

do i=1 to dim(_nearest);
    if _nearest(i) > value1 then leave;
end;
nearest = _nearest(i);
Difference = _nearest(i) - value1;

keep value1 nearest difference;

run;