Maths / graph puzzle

  • Thread starter Thread starter Nick
  • Start date Start date
N

Nick

Hi,

I'm sure I'm being dumb but I can't think of a way to solve this. Any
help appreciated.

Given three given values of "Start", "End" and "Length", I need a
function for variables time "T" and values "X" where at T = 1 X=Start
and at T=Length X=End. However if you graph T and X (T along the Y axis
and X along the X axis) I'd like the graph to look something like the
graph of 1/X, i.e. an exponential like "fade" from Start to End over T
periods.

Hope this makes sense - any ideas appreciated!

Nick
 
probably,

X = (T - 1)/(Length - 1) * (End - Start) + Start

for different values between T = 1 to Length, use the above formula, and
then plot the reqd graph.


Mangesh
 
Assuming that your data are such that they will result in the kind of
chart you want...

Plot the T and X data in a XY Scatter chart. Then, double-click the y-
axis. In the resulting dialog box, select the Scale tab. In there
check the options for 'Values in reverse order' and 'Value (X) axis
crosses at maximum value'

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Multi-disciplinary business expertise
+ Technology skills
= Optimal solution to your business problem
Recipient Microsoft MVP award 2000-2007
 
Hi,

Thanks for the reply. Worked out this formula for a straight line
decrease. What I really am looking for is a way of making the decrease
not a straight line - i.e. a gradual fade, where in the last year the
decrease is far greater than in the first (and also a way of reversing
it so that the decrease in the last year is much less than the decrease
in the first).

Any more ideas?

Nick
 
Back
Top