In university, performant means that you have an optimal solution in O(n) notation. You might get a remark on your paper about using made up words instead of the proper terminology though. In business, performant means that your customer hasn’t complained about the speed (yet). Your product is also buzzword compliant.
I can reproduce this on my Q6600 (Python 2.6.2); increasing the range to 100000000: (‘+=’, 11.370000000000001) (‘-=’, 10.769999999999998) First, some observations: This is 5% for a trivial operation. That’s significant. The speed of the native addition and subtraction opcodes is irrelevant. It’s in the noise floor, completely dwarfed by the bytecode evaluation. That’s talking about … Read more
Three suggestions: Use one dictionary. It’s easier, it’s more straightforward, and someone else has already optimized this problem for you. Until you’ve actually measured your code and traced a performance problem to this part of it, you have no reason not to do the simple, straightforward thing. Optimize later. If you are really worried about … Read more
I currently use this, with Excel 2007 public static string ExcelColumnFromNumber(int column) { string columnString = “”; decimal columnNumber = column; while (columnNumber > 0) { decimal currentLetterNumber = (columnNumber – 1) % 26; char currentLetter = (char)(currentLetterNumber + 65); columnString = currentLetter + columnString; columnNumber = (columnNumber – (currentLetterNumber + 1)) / 26; } … Read more
That depends entirely on the ISA you’re compiling for, and the quality of your compiler’s optimizer. Don’t optimize prematurely: profile first to find your bottlenecks. That said, in x86, you’ll find that both are equally fast in most cases. In both cases, you’ll have a comparison (cmp) and a conditional jump (jCC) instructions. However, for … Read more
Why not just: (val, max, min) => (val – min) / (max – min);
An approach that might work is to write these two methods: public static void WithInt() { int x = 5; Console.WriteLine(x); } public static void WithVar() { var x = 5; Console.WriteLine(x); } Compile, and use ildasm to examine the produced CIL. Show your boss. edit @ck has done all but the last step for … Read more
Using unsafe and compiled as x64 result: Implementation | Exec | GC #1 Simple | 4706ms | 0ms #2 Simple parallel | 2265ms | 0ms #3 ParallelSubstring | 800ms | 21ms #4 Fredou unsafe | 432ms | 15ms take the code of Erti-Chris Eelmaa and replace my previous one with this. I don’t think I … Read more
From the MSDN Documentation: “Before you call Prepare, specify the data type of each parameter in the statement to be prepared. For each parameter that has a variable length data type, you must set the Size property to the maximum size needed. Prepare returns an error if these conditions are not met. If you call … Read more