On Tuesday 01 December 2009, questions anon wrote: > I would now like to add a line of best fit. I think the command is > polyfit()?? > But I can't seem to get it to work
These are the steps to make polyval work. I typed it into an 'ipython -pylab' session; I hope I included all relevant lines and I removed some of the output: #this is the input data In [13]:d_x = [0, 0.1, 0.3, 0.5, 0.7, 1, 1.2, 1.5, 1.8, 2] In [14]:d_y = [0.1, 0.11, 0.15, 0.3, 0.5, 0.8, 1, 1.2, 1.1, 1.2] #show input data In [15]:plot(d_x,d_y, label='data') #make 2nd degree polynom, and plot smoothly with 50 points In [17]:pol2 = polyfit(d_x, d_y, 2) In [18]:p_x = linspace(0, 2, 50) In [19]:p2_y = polyval(pol2, p_x) In [20]:plot(p_x,p2_y, label='pol 2nd') #also create line and plot it too (would not need 50 points) In [21]:pol1 = polyfit(d_x, d_y, 1) In [22]:p1_y = polyval(pol1, p_x) In [24]:plot(p_x,p1_y, label='line') #create legend so you can recognize the curves In [25]:legend() Eike. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
