Posts Tagged ‘ performance models ’

Q-Q Plots for Multi-modal Performance Data

August 3, 2011
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Q-Q Plots for Multi-modal Performance Data

I'm in the process of putting together some slides on how to apply Quantile-Quantile plots to performance data. Q-Q plots are a handy tool for visually checking how well your data matches a known probability distribution (prob dsn). If the match is goo...

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Confidence Bands for Universal Scalability Models

September 7, 2010
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Confidence Bands for Universal Scalability Models

In the recent GDAT class, confidence intervals (CI) for performance data were discussed. Their generalization to confidence bands (CB) for scalability projections using the USL model also came up informally. I showed a prototype plot but it was an ugl...

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Where to Start with PDQ?

August 30, 2010
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Where to Start with PDQ?

Once you've downloaded PDQ with a view to solving your performance-related questions, the next step is getting started using it. Why not have some fun with blocks? Fun-ctional blocks, that is. Since all digital computers and network systems can be cons...

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PDQ 5.0 Test Suite or … How I Spent My Weekend

June 29, 2009
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PDQ 5.0 Test Suite or … How I Spent My Weekend

I was planning to blog about the amazing time I had at Velocity 2009 last week, when this landed in my mailbox (edited for space and privacy): Subject: Seeking help with PDQ-R ...Date: Thu, 25 Jun 2009 15:51:21 -0500My name is James and I've be...

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Plotting PDQ Output with R

February 27, 2009
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Plotting PDQ Output with R

One the nice things about PDQ-R (coming in release 5.0) is the ability to plot PDQ output directly in R. Here's a PDQ-R script, together with the corresponding graphical output, that I knocked up to show the effect on the throughput curve of adding mor...

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PDQ-R Lives!

February 22, 2009
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PDQ-R Lives!

After some fiddling to get things linked correctly to the R binaries on my new Macbook, the first PDQ-R test model has run successfully! Here 'tiz ...This is an important step for PDQ development and is due entirely to the efforts of Phil Feller. Natur...

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