Exponential Function

Go To Last Post
5 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Guys, I have a function that returns an exponential graph.  It starts at 0.4 falling to 0.2.  This works.  However the exponential starts at 0.4 falling slow and getting faster.  I want it to start at 0.4 falling fast and slowing down.  

 

test_var = (double)(0.2 * (1.0 / (1.0 + (exp(i))))) + 0.2;

Thanks for the help guys.

This topic has a solution.
Last Edited: Mon. Feb 15, 2021 - 08:54 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Please can you upload a hand drawing that approximates the desired curve?

 

Starting from i -inf , any fall is slow.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0


 

abdulai wrote:

Please can you upload a hand drawing that approximates the desired curve?

 

Starting from i -inf , any fall is slow.

 

 

Last Edited: Mon. Feb 15, 2021 - 07:11 PM
This reply has been marked as the solution. 
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Why not use Excel?...then you can rapidly adjust the constants like k1exp(-k2t)  to get the exact shape you want?   

Your curve looks rather 1/x like---maybe that is preferred? you can even use Excel* to compare them side-by-side.

Excel can also do a fit (built in--- just right-click on a plot line) to polynomials, exponential, etc, if you give it a bunch of desired points (select "show equation" option)

 

*or Open Office, which is a great freebie

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

avrcandies wrote:

Why not use Excel?...then you can rapidly adjust the constants like k1exp(-k2t)  to get the exact shape you want?   

Your curve looks rather 1/x like---maybe that is preferred? you can even use Excel* to compare them side-by-side.

Excel can also do a fit (built in--- just right-click on a plot line) to polynomials, exponential, etc, if you give it a bunch of desired points (select "show equation" option)

 

*or Open Office, which is a great freebie

 

Thanks guys for the input.