ni.com is currently undergoing scheduled maintenance.

Some services may be unavailable at this time. Please contact us for help or try again later.

LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

equation solving

I would like to plot the following equation
I=exp(x-I)

Is there any easy way to solve for 'I' having a given x?
0 Kudos
Message 1 of 6
(3,357 Views)
Hi....try this....it will give you any number to any power, positive or negative.

Eric
Eric P. Nichols
P.O. Box 56235
North Pole, AK 99705
0 Kudos
Message 2 of 6
(3,357 Views)
Thanks, but I can't tell. My LV 6.1 is choking on your LV7.0 file.
0 Kudos
Message 3 of 6
(3,357 Views)
Try this one.
0 Kudos
Message 4 of 6
(3,357 Views)
Is that a number 1 in your exponential or a letter I? If it's the number 1 then the simple answer that you've been given will work. If it's the letter I then you have an algebraic equation of x=I+ln(I). Perhaps you could construct your array in reverse (i.e., determine x in terms of I) and then plot it the other way. I have attached a simple example. You could use a case structure in conjunction with a while loop instead of the for loop to set upper and lower limits on the value of x. Note that this will not give you equidistant x values.

There are certainly ways to solve for the value of I, but at present I can't think of any which are straightforward.

Hope this helps.

John
0 Kudos
Message 5 of 6
(3,357 Views)
Unfortunately it is the letter I. Perhaps Y=exp(X-Y) is clearer. And also I need to find Y for a given X not the reverse. Just plotting it the other way is difficult since Y will be varying over orders of magnitude while X isn't. And I would like it to be more general.

I could do this with the full out Lev-Marq but that seemed way overkill. I'm still hoping for a simple solution with a zero finder or something.
0 Kudos
Message 6 of 6
(3,357 Views)