dotnetperls-controls - Project Hosting on Google Code

Older Mar 13, 2009 issue 7 (Failed delivery to your email address) commented on by allen.sam - Hi Neil, thanks for the bug. I just realized this when I was wondering why I wasn't getting any spam. What happened was that I moved to a new virtual dedicated server. This somehow messed up the DNS records. For now I am going to use my yahoo address, sam.allen@rocketmail.com. I may change back to the dotnetperls.com address in the future. Thanks and sorry for the inconvenience. Hi Neil, thanks for the bug. I just realized this when I was wondering why I wasn't getting any spam. What happened was that I moved to a new virtual dedicated server. This somehow messed up the DNS records. For now I am going to use my yahoo address, sam.allen@rocketmail.com. I may change back to the dotnetperls.com address in the future. Thanks and sorry for the inconvenience. Mar 13, 2009 issue 7 (Failed delivery to your email address) reported by Foober22 - Hi Sam, It appears your email address is unable to receive email. I tried sending you a suggestion but received a failed delivery notice from GMail. Hi Sam, It appears your email address is unable to receive email. I tried sending you a suggestion but received a failed delivery notice from GMail. Feb 06, 2009 issue 6 (missing value for 7z compression level http://dotnetperls.co...) commented on by allen.sam - I looked at this and you are absolutely correct. I changed the document to list -mx0 and -mx1 separately. It will be on the site within a day. I want to ad a list of credits to the article and would be happy to put your (real) name if you want. Thanks. I looked at this and you are absolutely correct. I changed the document to list -mx0 and -mx1 separately. It will be on the site within a day. I want to ad a list of credits to the article and would be happy to put your (real) name if you want. Thanks. Feb 06, 2009 issue 6 (missing value for 7z compression level http://dotnetperls.co...) reported by googlymo...@hotmail.com - Page: http://dotnetperls.com/Content/7-Zip-Examples.aspx section: "Information: -m switch" entry: -mx0 Don't compress at all. Is called "copy mode" and "fastest." Correction: mx0 is Don't compress mx1 is Fastest eg 7za a -mx1 data.7z data compresses data in fastest mode 7za a -mx0 data.7z data compressed data in store mode (not compressed) Page: http://dotnetperls.com/Content/7-Zip-Examples.aspx section: "Information: -m switch" entry: -mx0 Don't compress at all. Is called "copy mode" and "fastest." Correction: mx0 is Don't compress mx1 is Fastest eg 7za a -mx1 data.7z data compresses data in fastest mode 7za a -mx0 data.7z data compressed data in store mode (not compressed) Dec 13, 2008 issue 4 (Performance measurement) commented on by mafut...@gmx.de - I'm sorry, i don't have any files online. The benchmarks are kind of easy to write and use, though. If you're interested in this topic, i recommend to have a look at JSN (http://www.javaspecialists.eu/archive/archive.jsp). Even though it is specific to Java, most of their principles also apply to C# and any other modern language and have always been a great source for digging into fun stuff. Kind regards, mafutrct. I'm sorry, i don't have any files online. The benchmarks are kind of easy to write and use, though. If you're interested in this topic, i recommend to have a look at JSN (http://www.javaspecialists.eu/archive/archive.jsp). Even though it is specific to Java, most of their principles also apply to C# and any other modern language and have always been a great source for digging into fun stuff. Kind regards, mafutrct. Dec 05, 2008 issue 4 (Performance measurement) commented on by allen.sam - It has been suggested I use Stopwatch also. Your suggestion is good that I use longer runs and average them. For my biggest article I did about 12 hours of benchmarks: http://dotnetperls.com/Content/Browser-Memory.aspx but that is different. I would like to see your Java benchmarks if you have them online. Just out of curiosity--I don't do Java :) It has been suggested I use Stopwatch also. Your suggestion is good that I use longer runs and average them. For my biggest article I did about 12 hours of benchmarks: http://dotnetperls.com/Content/Browser-Memory.aspx but that is different. I would like to see your Java benchmarks if you have them online. Just out of curiosity--I don't do Java :) Dec 05, 2008 issue 3 (Bug in http://dotnetperls.com/Content/Reorder-If.aspx) commented on by allen.sam - Thank you for bug #2! You are absolutely correct that the i < 100 will never be reached. The numbers are likely still close if I were to remove it, unless something else with the pipeline/IL code affects the loop instructions. Solution: I switched the two IF statements, and inserted a note that says the benchmark results are not 100% accurate for the example. The important part of the article is that the code should do the most important stuff first usually. Will upload it soon. Thank you for bug #2! You are absolutely correct that the i < 100 will never be reached. The numbers are likely still close if I were to remove it, unless something else with the pipeline/IL code affects the loop instructions. Solution: I switched the two IF statements, and inserted a note that says the benchmark results are not 100% accurate for the example. The important part of the article is that the code should do the most important stuff first usually. Will upload it soon. Dec 04, 2008 issue 4 (Performance measurement) reported by mafut...@gmx.de - Hi, i noticed that you're often using very quick benchmarks to measure performance. Even though your results all seem to be correct i suggest to use a slightly more advanced pattern to improve the credibility of your tests. I think a test run lasting less than a few seconds is too inaccurate. Usually every test run should take at least one minute. Additionally, there should be at least 3 test runs, whereas the first test run is to be ignored to make sure the machine is fully present at the second run. The following runs are averaged. I'm not yet very familiar with the .NET platform, but i guess using this method even very doubtful critics can be convinced of your results. I'm used to perform the above procedure in my Java benchmarks and it works great. Hope this is the right place to bring up this issue. And thank you for DNP, the site was helpful many times to me. :) Kind regards, mafutrct. Hi, i noticed that you're often using very quick benchmarks to measure performance. Even though your results all seem to be correct i suggest to use a slightly more advanced pattern to improve the credibility of your tests. I think a test run lasting less than a few seconds is too inaccurate. Usually every test run should take at least one minute. Additionally, there should be at least 3 test runs, whereas the first test run is to be ignored to make sure the machine is fully present at the second run. The following runs are averaged. I'm not yet very familiar with the .NET platform, but i guess using this method even very doubtful critics can be convinced of your results. I'm used to perform the above procedure in my Java benchmarks and it works great. Hope this is the right place to bring up this issue. And thank you for DNP, the site was helpful many times to me. :) Kind regards, mafutrct. Dec 04, 2008 issue 3 (Bug in http://dotnetperls.com/Content/Reorder-If.aspx) reported by mafut...@gmx.de - Hello again, i'm refering to this piece of code: [...] else if (i < 1000) [...] else if (i < 100) If i'm not mistaken, the i < 100 case is supposed to be impossible to occur since it was already handled by i < 1000. I don't see any better way to handle this other than moving the i < 100 case in front of i < 1000. This also affects the performance results slightly. But since the loop counter is > 2000 in almost all cases anyway, the impact is probably very small. Kind regards, mafutrct. Hello again, i'm refering to this piece of code: [...] else if (i < 1000) [...] else if (i < 100) If i'm not mistaken, the i < 100 case is supposed to be impossible to occur since it was already handled by i < 1000. I don't see any better way to handle this other than moving the i < 100 case in front of i < 1000. This also affects the performance results slightly. But since the loop counter is > 2000 in almost all cases anyway, the impact is probably very small. Kind regards, mafutrct. Dec 03, 2008 issue 2 (Unroll loop notice) commented on by allen.sam - "It is important that you only unwind loops so that the steps in the loops do not exceed the array bounds. The unwound loop above could have 2, 4, or 6 elements to loop over, but not 3, 5, or 7." "It is important that you only unwind loops so that the steps in the loops do not exceed the array bounds. The unwound loop above could have 2, 4, or 6 elements to loop over, but not 3, 5, or 7." Dec 03, 2008 issue 2 (Unroll loop notice) changed by allen.sam - Thanks mafutrct! You are absolutely correct that the +=2 part will go past the upper bounds if it is odd. Often with this kind of code the array sizes are well understood (whether it is odd or even). But I can certainly see this causing a bug. Summary: Unroll loop notice Owner: allen.sam Thanks mafutrct! You are absolutely correct that the +=2 part will go past the upper bounds if it is odd. Often with this kind of code the array sizes are well understood (whether it is odd or even). But I can certainly see this causing a bug. Summary: Unroll loop notice Owner: allen.sam Dec 02, 2008 issue 2 (Enter one-line summary) reported by mafut...@gmx.de - Hey :) I'm referring to the first example of http://dotnetperls.com/Content/Loop-Unwinding.aspx The unrolled loop does work, however, the i < a.Length; i += 2 part should have a notice about the upper array bounds. By adding one element to the array, we are supposed to get some array boundary exception. This problem can easily be solved in different ways, i'm positive you're familiar with these. Hope this message helps - kind regards, mafutrct. Hey :) I'm referring to the first example of http://dotnetperls.com/Content/Loop-Unwinding.aspx The unrolled loop does work, however, the i < a.Length; i += 2 part should have a notice about the upper array bounds. By adding one element to the array, we are supposed to get some array boundary exception. This problem can easily be solved in different ways, i'm positive you're familiar with these. Hope this message helps - kind regards, mafutrct. Oct 24, 2008 issue 1 (Test bug) reported by allen.sam - What steps will reproduce the problem? 1. One 2. Two 3. Three What is the expected output? What do you see instead? 4. Please use labels and text to provide additional information. Alright. What steps will reproduce the problem? 1. One 2. Two 3. Three What is the expected output? What do you see instead? 4. Please use labels and text to provide additional information. Alright.

issue 4 (Performance measurement) reported by mafut...@gmx.de - Hi, i noticed that you're often using very quick benchmarks to measure performance. Even though your results all seem to be correct i suggest to use a slightly more advanced pattern to improve the credibility of your tests. I think a test run lasting less than a few seconds is too inaccurate. Usually every test run should take at least one minute. Additionally, there should be at least 3 test runs, whereas the first test run is to be ignored to make sure the machine is fully present at the second run. The following runs are averaged. I'm not yet very familiar with the .NET platform, but i guess using this method even very doubtful critics can be convinced of your results. I'm used to perform the above procedure in my Java benchmarks and it works great. Hope this is the right place to bring up this issue. And thank you for DNP, the site was helpful many times to me. :) Kind regards, mafutrct.

Hi, i noticed that you're often using very quick benchmarks to measure performance. Even though your results all seem to be correct i suggest to use a slightly more advanced pattern to improve the credibility of your tests. I think a test run lasting less than a few seconds is too inaccurate. Usually every test run should take at least one minute. Additionally, there should be at least 3 test runs, whereas the first test run is to be ignored to make sure the machine is fully present at the second run. The following runs are averaged. I'm not yet very familiar with the .NET platform, but i guess using this method even very doubtful critics can be convinced of your results. I'm used to perform the above procedure in my Java benchmarks and it works great. Hope this is the right place to bring up this issue. And thank you for DNP, the site was helpful many times to me. :) Kind regards, mafutrct.

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