
From:  Przemek Klosowski 
Subject:  Re: Problem with plotting of functions for large arguments 
Date:  Fri, 30 Oct 2015 10:55:44 0400 
Useragent:  Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 
On 10/30/2015 05:09 AM, kschnikow
wrote:
The interval above must be a typo: you probably meant to sayDear all, I have a problem using the plot() functions for e.g. plotting the sine function for large arguments > 1e6 For example, when I define the intervall x=10000000*pi:4*pi/100/10000004*pi; and I try to plot(x,sin(x)) I get rubbish. x=10000000*pi:4*pi/100:10000004*pi Now, it's true that the resulting plot(x,sin(x)) is wrong. The values are actually correct, as shown by plotting them as points by plot(x,sin(x),'.'). This is because the default graphics toolkit, fltk, has issues with plotting large magnitude numbers because uses single precision floating point internally. Most Octave installs will have two graphics toolkits available: fltk and gnuplot, and gnuplot does not have this problem, so switch to it and the plot will come out fine: graphics_toolkit ('gnuplot') plot(x,sin(x)) 
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