Getting Simple Slope Of A Line

[charles phillipsParticipant]

Ok I started a User Showcase because I was getting some neat results, and now I have turned it into a “how do you do this?” post. Sigh. Can I switch it over here or just sort of continue the conversation here?

I have a very simple graph and want to get just the slope of a straight line, have added a Fit function.

Slope is 0.112?

Slope is 0.0311?

[dgteamModerator]

Hi Charles,

We can probably move the post, but for now let’s try to answer your question.

The Fit command article has a section on Fit results that shows how to view the output of the fit, including the slope.

In your case, you have to be careful as the x axis is time.  The labels show the months but the actual underlying scale is in seconds.  The slope will be the change in y / change in x, where x is in seconds.

For your first graph, the change in one month is about -5.  So you could have a ball park estimate of the slope:

-5/(60*60*24*32) = -0.00000180844907  1/sec

where is the unit is 1/sec.  If you wanted to have the change per day you would multiply by sec per day.

Does that help?

[Author]

Posts