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Re: [Gnuplot-info] explanation to a short script
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From: Jon <dev...@gm...> - 2011-02-15 22:08:27
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Dear Thomas, I attach the plot here for both cases using the dataset I listed in the previous email. You can see that the rescaled data really uses 0.1 as the minimum. By the way, I cannot understand what you mean by saying "but should be '0.09', '0.045', and '1'"? Shouldn't the first three be "9,4.5,1", as correctly shown in the plot I attach in this email? Thanks, Sincerely, Jon On Tue, Feb 15, 2011 at 1:06 PM, Thomas Sefzick <t.s...@fz...>wrote: > > the script correctly identifies 0.1 as the minimum, yes, > but not for all data points. > you may have noticed that the 1st three y-values in the plot are '1', > but should be '0.09', '0.045', and '1'. > > the script searches for the minimum by storing the actual y-value if > it's smaller than a previous one. as long as the absolute minimum > isn't found, i.e. the data line with the minumum y-value hasn't been > yet read, y-values are divided by the intermediate minimum. > that's the reason why the y-values are always '1' when reading > my data set. > > > bsmile wrote: > > > > Dear Thomas, > > > > I actually specifically checked whether the first script could capture a > > minimum hidden in the data except for the first line. The sample data I > > used > > is > > > > 1 0.9 > > 2 0.45 > > 3 0.1 > > 4 0.94 > > 5 0.44 > > 6 0.12 > > 7 0.36 > > > > and it seems a single pass corrected identified 0.1 as the minimum. As to > > your sample data, the missing of y range is a 2nd mysterious to me as if > I > > change the data to float, it works fine, and even if I interpret the data > > to > > be integer, it should still give the right answer instead of giving > > constant > > 1 for each dataline. > > > > Sincerely, > > Jon > > > > > > On Tue, Feb 15, 2011 at 2:31 AM, Thomas Sefzick > > <t.s...@fz...>wrote: > > > >> > >> strictly speaking, nunzio's script only works if the smallest number is > >> in > >> the > >> 1st data line. > >> > >> an example: > >> > >> #ts.dat: > >> 1 10 > >> 2 9 > >> 3 8 > >> 4 7 > >> 5 6 > >> 6 5 > >> 7 4 > >> 8 3 > >> 9 2 > >> 10 1 > >> > >> #script: > >> min=10**10 > >> grab(x)=x<min?min=x:min=min > >> plot 'ts.dat' using 1:($2/grab($2)) > >> > >> gives a horizontal line and a warning about the empty y-range. > >> this means that gnuplot behaves like other programming languages > >> and there is no magic behind it. > >> > >> a 2nd plot gives the correct result, as you have pointed out, > >> because then 'min' already contains the smallest value. > >> > >> #script: > >> min=10**10 > >> grab(x)=x<min?min=x:min=min > >> plot "ts.dat" using 1:($2/grab($2)), "" using 1:($2/grab($2)) > >> > >> ... , "" using 1:($2/grab($2)) > >> is equivalent to > >> ... , "" using 1:($2/min) > >> > >> > >> bsmile wrote: > >> > > >> > Dear Thomas, > >> > > >> > Nunzio Losacco wrote a short script to get each number divided by the > >> > smallest number in a specific column, as > >> > min=10**10 > >> > grab(x)=x<min?min=x:min=min > >> > plot 'disy.100' u 1:($3/grab($3)) > >> > > >> > I don't quite understand the logic behind although I checked that it > >> works > >> > fine. If I were to do this, I would write something like > >> > > >> > set term dumb > >> > min=10**10 > >> > plot 'disy.100' u ($3<min?min=$3:min=min,$1):3 > >> > > >> > set term x11 > >> > plot 'disy.100' u 1:($3/min) > >> > > >> > and you easily see the idea I wrote it this way. I think this reflects > >> a > >> > big > >> > problem for me to understand deeply how gnuplot deals with datafile > and > >> > how > >> > it plots, which is obviously different from the standard programming > >> > languages. Thanks for your in-depth explanation or references, > >> > > >> > Sincerely, > >> > Jon > >> > > >> > ------------------------------------------------------------------------------ > >> > The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio > >> XE: > >> > Pinpoint memory and threading errors before they happen. > >> > Find and fix more than 250 security defects in the development cycle. > >> > Locate bottlenecks in serial and parallel code that limit performance. > >> > http://p.sf.net/sfu/intel-dev2devfeb > >> > _______________________________________________ > >> > gnuplot-info mailing list > >> > gnu...@li... > >> > https://lists.sourceforge.net/lists/listinfo/gnuplot-info > >> > > >> > > >> > >> -- > >> View this message in context: > >> > http://old.nabble.com/explanation-to-a-short-script-tp30924408p30928896.html > >> Sent from the Gnuplot - User mailing list archive at Nabble.com. > >> > >> > >> > >> > ------------------------------------------------------------------------------ > >> The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio > XE: > >> Pinpoint memory and threading errors before they happen. > >> Find and fix more than 250 security defects in the development cycle. > >> Locate bottlenecks in serial and parallel code that limit performance. > >> http://p.sf.net/sfu/intel-dev2devfeb > >> _______________________________________________ > >> gnuplot-info mailing list > >> gnu...@li... > >> https://lists.sourceforge.net/lists/listinfo/gnuplot-info > >> > > > ------------------------------------------------------------------------------ > > The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: > > Pinpoint memory and threading errors before they happen. > > Find and fix more than 250 security defects in the development cycle. > > Locate bottlenecks in serial and parallel code that limit performance. > > http://p.sf.net/sfu/intel-dev2devfeb > > _______________________________________________ > > gnuplot-info mailing list > > gnu...@li... > > https://lists.sourceforge.net/lists/listinfo/gnuplot-info > > > > > > -- > View this message in context: > http://old.nabble.com/explanation-to-a-short-script-tp30924408p30934168.html > Sent from the Gnuplot - User mailing list archive at Nabble.com. > > > > ------------------------------------------------------------------------------ > The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: > Pinpoint memory and threading errors before they happen. > Find and fix more than 250 security defects in the development cycle. > Locate bottlenecks in serial and parallel code that limit performance. > http://p.sf.net/sfu/intel-dev2devfeb > _______________________________________________ > gnuplot-info mailing list > gnu...@li... > https://lists.sourceforge.net/lists/listinfo/gnuplot-info > |
