Author Archives: fastexcel

Excel JavaScript API Part 5: The large numbers bug

There is currently (JavaScript Excel API set 1.4) a rather nasty bug when writing large integer numbers (anything larger than int32) back to a range. The JS can correctly read these large numbers – it just silently gets the wrong … Continue reading

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Excel JavaScript API Part 4: The shallow copy problem

I was trying to read the values from a Range and then write modified versions of the values to two different ranges. Should be straightforward: Well this does not work: both B4 and B6 have 0.91 added to them: wrong … Continue reading

Posted in arrays, Excel, JS-API | Tagged , | 1 Comment

Excel JavaScript API Part 3: Benchmark of Processing Arrays Performance – Loop vs Reduce vs COUNTIFS vs VBA

In a previous post I compared several different ways of processing data with VBA. The fastest way was to get the data into a variant array and loop on it. JavaScript has some powerful array methods so I wanted to … Continue reading

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Excel JavaScript API Part 2: Benchmark of Read/Write Range Performance

As an Excel Office Developer many of the Excel based applications I develop depend on reading data from Excel worksheet ranges, processing it and then writing the processed data back to a worksheet. In VBA the way to do this … Continue reading

Posted in arrays, Calculation, JS-API, VBA | Tagged , , | 1 Comment

Excel Range.Value(ValueType): What is this parameter?

Whilst visiting Microsoft Research in Cambridge I was chatting to fellow MVP Roger Govier. He mentioned that he was using this strange parameter to the Range.Value (ValueType) method, which I had been meaning to look at for a long time … Continue reading

Posted in Formatting, VBA | Tagged , | 5 Comments

Excel JavaScript API Part 1: Overview & Comparison

I have been spending time in the last few months experimenting with the new JavaScript Excel API. This is the first of a planned series of posts examining the JS-API from the point of view of an Excel Office developer. … Continue reading

Posted in .NET, JS-API, UDF, Uncategorized, VBA, XLL | Tagged , , , , | 2 Comments

Why Structured References are slow in Excel 2013 but fast in Excel 2016

Tables have a bad reputation for performance. Zack (Firefytr) Barresse (who wrote the definitive guide to Excel Tables with Kevin (Zorvek) Jones) recommends a limit of around 10K rows for tables if you want to keep performance reasonable. Prompted by … Continue reading

Posted in Calculation | Tagged , , , , , | 5 Comments

Excel Versions Screen Test (Updated): how fast is Screen Updating?

Gurs has an interesting benchmark he has been running on various systems and Excel versions over the years. His results seem to show a massive performance decline in later Excel versions. Looking at his benchmark and its VBA code you … Continue reading

Posted in Calculation, Formatting, Uncategorized, VBA | 9 Comments

Excel Memory Checking Tool: Using LAA to increase useable Excel memory

Most of us sooner or later get hit by one or more of the dreaded messages “Out of Memory” or “Excel cannot complete this task with available resources” or “Not enough System Resources/Memory to Display Completely” , regardless of how … Continue reading

Posted in Memory, VBA | Tagged , , , , | 9 Comments

2016 Microsoft MVP Summit, Part 2: Trump Wins

Tuesday November 8 I was in Redmond at the Microsoft MVP Summit. It was also the day of the USA presidential election. This was my flashbulb moment, observed from a European perspective: A small group of us Excel MVPs (Roger … Continue reading

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