Monthly Archives: January 2012

Writing Efficient UDFs Part 9 – An Example – Updated

Pedro wants to know how to speed up his UDF, which needs to calculate results for 35040 cells the minimum difference between the cell and a column of values of unknown length. Pedro’s UDF There is a fundamental problem with … Continue reading

Posted in Calculation, UDF, Uncategorized, VBA | 12 Comments

Excel 2010 Tables/Listobject: slow update and how to bypass

There was an interesting post on Stack Overflow recently about a performance problem when updating Excel 2007/2010 Tables/Listobjects. Certainly something strange is going on! Duplicating the Problem 1. Create a table by selecting a few cells (I used A1:A3) on … Continue reading

Posted in Calculation, VBA | 13 Comments

Writing efficient VBA UDFs (Part 8) – Getting the previously calculated value from the calling cells

If you have a UDF that depends on some slow-calculating resource you may want the UDF to mostly just return the values obtained  at the last calculation from the cells the UDF occupies, and only occasionally go and use the … Continue reading

Posted in Calculation, UDF, VBA, XLL | 23 Comments