Category Archives: Calculation

Writing Efficient VBA UDFs Part 14: Handling whole columns using Implicit Intersection – Updated

Excel has an interesting and very efficient trick called Implicit Intersection which allows you to use large Named Ranges and whole column references efficiently. What is Implicit Intersection? When Excel expects to get a single cell reference but you give … Continue reading

Posted in arrays, Calculation, UDF, VBA, XLL | Tagged , , , , | 2 Comments

Excel What-If Data Tables: Faster calculation with VBA

For some reason this year I keep on meeting Excel’s What-If Data Tables. These are used (often in real estate and financial valuation models) to simplify doing sensitivity analysis against a range of values for certain inputs such as interest … Continue reading

Posted in arrays, Calculation, VBA | 2 Comments

Excel Full Column References and Used Range: Good Idea or Bad Idea?

Some people love using full column references such as A:A, other people say they slow down your workbook to a crawl and lead to workbook and memory bloat. The attraction of using whole column references is that you don’t have … Continue reading

Posted in arrays, Calculation, Formatting, Memory | 5 Comments

Timing Calculation Consistently: Windows Update/Background Process Woes

Last Friday¬† 4 December 2015 I was presenting a session at the Modeloff Global Training Camp in London. The session was “How to make your Excel workbooks calculate faster”, and so it involved demonstrations of timing formula calculation. No problem … Continue reading

Posted in Calculation | Leave a comment

Excel User Voice and Workbook Calculate

Excel User Voice At the recent Excel Global Summit the Excel team were keen to explain how they have started using Excel User Voice to ask for and prioritise product improvement suggestions. https://excel.uservoice.com/ There are 2 important things to note … Continue reading

Posted in Calculation | Tagged , , | 4 Comments

Writing Efficient VBA UDFs (Part13): MaxMinFair Resource Allocation – an array UDF example

Last year we got to spend a great day at Microsoft Research in Cambridge (UK). one presentation was about storage strategies and featured (amongst other stuff) an interesting algorithm called MaxMinFair. The MaxMinFair algorithm You can read about it here … Continue reading

Posted in arrays, Calculation, UDF, VBA | Tagged , , | Leave a comment

Excel Circular References: Calculation, Detection, Control and Removal

Circular references in Excel are generally bad news: They are slow to calculate They can be hard to detect An intentional circular reference can mask an unintended circular reference, They do not always converge The Status Bar always shows calculate … Continue reading

Posted in Calculation | Tagged , , , | Leave a comment

Excel ForceFullCalculation: Trading off Editing speed vs Calculation speed

A recent post at Stack Overflow reminded me that I have not posted about the pros and cons of Excel’s Workbook.ForceFullCalculation property. So what does Workbook.ForceFullCalculation do? The simple answer is that it switches off Excel’s smart recalculation algorithm, so … Continue reading

Posted in Calculation, Memory, Uncategorized, VBA | Tagged | 7 Comments

Timing Excel Formula Calculations

I have written a couple of posts previously about the methodology of timing Excel calculations: A Quantum of Time – measuring time accurately The XIPS Challenge – how fast does Excel calculate? But rather than focus exclusively on how to … Continue reading

Posted in Calculation, Uncategorized | Tagged , , , | 1 Comment

Stacking (Appending) Arrays/Ranges in Excel: Formulas versus Functions Shootout

This post is a follow up to my last post Using Constant Arrays and Expressions in Excel Formulas. I will explore how some of the general purpose array-handling functions in FastExcel SpeedTools Extras compare with formulas using native Excel functions. … Continue reading

Posted in arrays, Calculation, Lookups, Uncategorized, XLL | Tagged , , , , , , , | 6 Comments