Does this functionality exist in MathCAD?

[AReed]

I am trying to recreate an equation in mathCAD from an algorithm formed in in Excel. I know the general format of the of the equation (C*e^-kx), I know x is the variable and I know the constant C and all of the factors that contribute to the formation of k but I don't know how each input contributes to k. I am wondering if any of you know of a function in MathCAD (or even excel) to where I can plug in k and all of the variables that contribute to k and solve for the signs (X/+-) that make a pool of factors equal k. If it really comes down to it I will have to plug and chug to find the order of operations to take my variables constitute k. This is not for school this is not for job/money, only personal a pet project to clear one's mind. So does a function of this power exist?

 

[GregLocock]

Can you have another go at explaining what you want? it sounds like you want to do a best fit to a bunch of data. perhaps a copy of your spreadsheet would help

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[AReed]

I have a set of variables, five to be exact (a,b,c,d & e) and a single solution k. I am trying to find a way to acquire the list of operations in which said variables form the solution k.


a=68.0388555
b=2.424937
c=0.0508
d=4
e=4

k=-1.59080982659757

 

[IFRs]

This k is a terrible thing. It probably has some unit conversions, perhaps density and other real factors but may also have a 2 or 10 or some constant that was artificially used for a factor of safety, curve fit, etc. I find it best to plug in all the units and based on known answers determine the value of k that works. If you know what goes into k, put them all in including units and then determine what constant you need to make the answers match a series plain equations that bound the useful range of the equation.

 

[AReed]

This may be of some help. The green cells are a-e and k is represented in the trend-line on the graph.