Author: Vincent

Feb

Specious spreadsheet security

If not for Chinese, it would’ve worked. So in Excel, you can set a password for either protecting a particular worksheet, or protecting the entire workbook/spreadsheet. This password is then hashed, and the result is stored within the spreadsheet contents. Now with the use of Open XML spreadsheets, this means the resulting hash is stored […]

Jan

SpreadsheetLight version 3

Version 3 of my spreadsheet library is now available. There’s a whole bunch of updates, including Excel 2010 conditional formatting such as data bars with negative value fill colours and icon sets with no icons. SpreadsheetLight is possibly the most developer-friendly spreadsheet library ever. Even if I do say so myself. 🙂

Jan

In The Mirror (cover)

This is one of my favourite piano pieces by Yanni. I’m not a pianist. I’ve never taken piano lessons. I’m like grade -1 or something. This took me over a dozen tries… Credits and permission granted from: Music by Yanni 23rd Street publishing Inc/Yanni Music Publishing (ASCAP) Used by Permission. All Rights Reserved

Jan

Passion problems

It was a fluke. I just fell into the spreadsheet business. My main products currently, both in writing and in code, revolve around spreadsheets. Specifically around Excel workbooks or spreadsheets or files or whatever you call them. I like programming and writing code. I’m great at it. I just didn’t specifically choose making spreadsheet libraries. […]

Dec

Regular polygon equation

A while ago, a blog reader named BJ (he seems to prefer being called BJ. He? *checks email…* Yeah, he) emailed me with his answer to this question: Is there an equation to describe regular polygons? I’m not clever enough to do much editing and explanation, so I’ll post his email (got his permission and […]

Nov

Modulo 26 and column names

I was sitting in the lecture theatre valiantly trying to keep awake. The professor was speaking on the rigorous application and proving of the modulus function. It’s basically the remainder, but I’ve never been introduced to it in such, uh, rigor. He brought up an example using modulo 26. And demonstrated the wrapping around of […]

Nov

Being a software god is tough

“Can this value be negative?” asked my colleague. We were in a meeting with a product manager to get project requirements. The software application was to calculate settlement revenue between our company and our company’s partners, who were content providers. We charge the public customers for the content, then we share the revenue with the […]

Nov

Calculate Excel column width pixel interval

Brace yourself. You’re about to learn the secret behind how Excel mysteriously calculates the column width intervals. In this article, I’m not going into the details of the column widths, but the column width intervals. There’s a difference. From the Open XML SDK specs: width = Truncate([{Number of Characters} * {Maximum Digit Width} + {5 […]