×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Two sums and two variables

Two sums and two variables

Two sums and two variables

(OP)
How to write an equation in mathcad with two sums and two variables
For example: sum of all i-es and sum of all j-es, of equation q*k*yij

RE: Two sums and two variables

(OP)
I forgot to tell, program is Mathcad :D

RE: Two sums and two variables

I don't understand. You haven't defined anything at all, other than about 5 constants. What is t[i,j? why is k only k, when it appears that you want it dependent on t[i,j?

I suggest that you use the help files and read the examples, or ask your instructor

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Two sums and two variables

(OP)
QLFG = maximum expected LFG generation flow rate (m3/yr)
i = 1 year time increment
n = (year of the calculation) – (initial year of waste acceptance)
j = 0.1 year time increment
k = methane generation rate (1/yr)
Lo = potential methane generation capacity (m3/Mg)
Mi = mass of solid waste disposed in the ith year (Mg)
t[ij] = age of the j-th section of waste mass Mi disposed in the i-th year (decimal years)
MCF = methane correction factor
F = fire adjustment factor

My job is to solve this equation, but I have to explain mathcad this t[i,j] variable, because it's dependable of i and j. Even if I assign this variable with any number, my equation won't work... Anyone?

RE: Two sums and two variables

What I meant is that you have failed to enter any VALUES to the variables. How do you expect a program calculate an answer where you've provided no inputs?

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Two sums and two variables

Well, don' you think you're going to need a table of 160 values to enter? You can insert an Excel component, which will create an embedded worksheet, through which you can add in the values you need

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Two sums and two variables

(OP)
I think of that, just occured to me, well, thanx for now, if I need something else... Thanx a lot man :D

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources