I was trying to plot a regression line with gnuplot, but instead to plot a straight line plot a line full of bend.I printed it in png format.Here a pic.

enter image description here

  • 1
    I think the curve is an optical illusion - those look like straight lines to me. By having the data points on the curve there, it can give that optical illusion. Commented Dec 8, 2015 at 21:48
  • So, how can I make it less serrated? I have to increase resolution? And how can I increase resolution in a simple way without having to change the dimension of lines dots and index?
    – Tarlo_x
    Commented Dec 8, 2015 at 21:52
  • Use a size parameter with set term.
    – muru
    Commented Dec 8, 2015 at 21:55
  • In this way I have to change all the dimensions of dots lines and index. I tried with 'set terminal png size 1024,768'
    – Tarlo_x
    Commented Dec 8, 2015 at 21:59

1 Answer 1


Given that the original question asks about why it's curved (and not about how to 'reduce the low-resolution segregation-ness' which is now being asked in comments):

The lines aren't actually curved. It's an optical illusion as a result of the data points being around the line, close enough to mess with your perception of the actual state of the line - it's really actually straight.

An example of this is seen in the U&L Meta post on the Community Promotion Ads - this post on the ad list shows how the lines are perceived as curved, when they're really actually straight.


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