Re: [Gnuplot-info] Gnuplot: How to convert STRINGS in DOUBLE? (with AWK)

[AstroPhysik <bwv...@gm...>]

Hi Thomas,
Thank you very much!
plot "star.dat"   using 7,  f(x) t "mean <x>" ,  1.*GewMW t "w.mean" w l
did the trick   =)

regards AP.


Thomas Sefzick wrote:
> 
> just tell gnuplot that 'GewMW' doesn't contain a filename but a numerical
> value:
> plot 1.*GewMW
> 
> 
> AstroPhysik wrote:
>> 
>> Hi Folks!
>> How can i convert in gnuplot strings to double?
>> 
>> I use AWK for calculating in a data file some weighted means. The result
>> should be displayed in gnuplot.
>> 
>> GewMW = system("gawk '{total+=$7; Nges+=1; Mean =
>> total/Nges;PhysikalischeWerte[$7] = $7;for(i=1; i<=Nges;i++)
>> Gewichtung[i] =  100.00 -((100.00/Nges) * (i-1));for(i=1; i<=Nges;i++)
>> SummeGewichtung += Gewichtung[i];for(i=1; i<=Nges;i++) SummeMW += (Mean *
>> Gewichtung[i]);GewichteterMittelwert =SummeMW /SummeGewichtung; } END
>> {print GewichteterMittelwert }' Stern.dat");
>> 
>> 
>> print GewMW
>> 
>> print GewMW shows the correct result but AWK or Gnuplot convert here the
>> result to a string: "GewMW = system(..)"  which is saved in GewMW.
>> This string i cannot process with plot..
>> 
>> plot "Stern.dat"   using 7,  f(x) t "mean <x>" ,  GewMW t "w.mean" w l
>> 
>> .. shows only the first mean but not the weighted mean from the value
>> GewMW (because it is a string here..)
>> 
>> i've also written a small  C++ Programm "stringToDouble(.. string )"
>> which returns a double, but i cannot call it in the correct way from
>> gnuplot?
>> 
>> GewMW = system(  stringtodouble(GewMW) );
>> GewMW = system("./stringtodouble(GewMW)");
>> 
>> The Listnings above bring  the errormessages:
>> "Star.dat", line 93: undefined function: stringtodouble
>> and:
>> sh: Syntax error: word unexpected (expecting ")")
>> 
>> I also tried to save the output to a file..
>> 
>> save '|grep GewMW >temp.dat';
>> 
>> and try to re-read it in gnuplot, hoping it will be interpreted as a
>> numeric value (double)..
>> 
>> Ähhhmmm, yes.. so faar.. nothing is working..
>> 
>> Does anyone have a tip which is more elegant/beautiful as mine are?
>> 
>> Thank you, :-)
>> AstroPhysik
>> 
> 
> 

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