# FindRoot solving of Excel input columns

Hi, I've posted another thread asking for general help on how to solve numerically with excel. Here is my specific situation if anybody is well versed with Mathematica programming. I'd appreciate any help.

I've successfully created a FindRoot to solve eqn's for one set of data points. However, I really need to automate this... here's what I'm working on:

A's are columns of excel data with a several hundred rows of data.
k's are constants
t's are variables to solve and plot.

k1=#; k2=#; k3=#;
Eqn1 = t1 - k1*Log[ 1 + (A1/A3)*(1 - exp(-t3)*(exp(-t2) ];
Eqn2 = t2 - k2*Log[ 1 + (A2/A3)*(1 - exp(-t3/) ];
Eqn3 = t3 -k3*t2;
FindRoot[{Eqn1==0,Eqn2==0,Eqn3==0}, { {t1,1},{t2,1},(t3,1} } ]

What I'd like to do is...
1. import 4 column (A1,A2,A3,A4) excel sheet, where A4 is carried through and not processed.
2. export 4 column results for (t1,t2,t3,A4) to xls, and plot t1 vs A4, t2 vs A4, t3 vs A4 in mathematica.

I've read through help to no avail... and have tried some kind of For loop on this FindRoot, and haven't been successful.

Much appreciate anybody's help.
PS - No budget currently for Wolframs Excel applet for Mathematica ;-)

Regards,
John

Last edited:

Ygggdrasil
Gold Member
I don't use mathematica, so I can't help with that, but there are other software, such as the freely available software R, which are made for reading, manipulating and writing large data sets:
https://www.r-project.org/

Last edited:
Dr Transport