# Interpolate strings from an x y interval to a corresponding x y interval.

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Peter Wray on 6 Mar 2022
Answered: Peter Perkins on 7 Mar 2022
I am restructuring a database and I have two tables in different formats but with the same information. Table One is a combination of values and strings where the from-to data are in custom intervals rounded to the nearest '0.25' as follows:
.
Table two is the same range of values and contains all the same integers but is formatted as fixed incremental 'blocks' instead of custom intervals.
I want to take the strings from table 1 and interp them onto table 2 so that if the 'from-to' values of table 2 falls within the range of an interval in table 1 it will have the corresponding strings as imagined below.
I can not seem to find a function that will allow me to perform this task with strings.
Any help would would be very much appreciated, thanks!
##### 2 CommentsShowHide 1 older comment
Peter Wray on 6 Mar 2022
Roger. Sorry about that I'm new.
intervalfrom = intervals(:,1);
intervalto = intervals(:,2);
string1 = intervals(:,3);
string2= intervals(:,4);
blockfrom = blocks(:,1);
blockto = blocks(:,2);
x = interp2(blockfrom,blockto,string1,intervalfrom,intervalto);

Jan on 6 Mar 2022
The solution is not to do this with strings directly, but with indices:
idx = interp1(table1{:, 1}, 1:height(table1), table2{:, 1});
Now use this index to fill the column of table2.
One problem is, that e.g. the 0.25 appears at final point of one interval and the start point of the next one. To which of the two does 0.25 belong?
Peter Wray on 7 Mar 2022
Hello, yes you should, I saved it as a matlab table under the names intervals but didn't change the name with code.
I rearanged my data base so it would index correctly (ran into a few issues after the inital one you pointed out), and then ran a fix on the index so it was all positive integers then used your code to add over the strings. Thank you so much and sorry for the bad formating. I'll do much better next time.

Peter Perkins on 7 Mar 2022
If you had timetables, ths would be a one-liner using synchronize. from and blocksFrom look suspiciously like time vectors. Timetables might make your life easier, but hard to tell.

R2021b

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