Frequency response graphs

[danielmckenna]

I need to get autograph to draw frequency response graphs for me and I can\'t get it to do it right. My largest value for the y axis can not be exceeded by the curve and it has to pass through all the points.

However a curve of best fit goes well above the highest y value

http://www.learnabout-electronics.org/ac...10-4-1.gif this is the sort of graph I\'m looking to draw (both curves are examples of types of curves I want to draw)

Any help would be appreciated

Thanks

-Daniel McKenna

[Simon]

Dear Daniel,

Can you please provide us with the data you are using?

Thanks,

Simon

[danielmckenna]

Frequency (Hz)

[Simon]

Dear Daniel,

The issue is that Autograph does not know you are trying to plot an impedance curve it just knows it has to fit three points. The Best Fit option will plot the correct quadratic through the three points but it is not "correct" because of the context of the question.

We know it is not "correct" because we have more information about the curve. We know roughly what we expect it to look like. Therefore we need to give this information to Autograph.

We can give this information to Autograph by plotting a curve of a particular form. In this case we want a curve with one peak but that has a horizontal asymptote at y = 0.

For example (there are many others!):

y = exp(-x