×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*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.

Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

(OP)
Excel defaults to a "standard" way of producing graphs -> simple x,y plots of the numbers in a table. You produce a table of numbers in columns, it produces any variety of "plots of dots"

But, I want to "test" the output of equations (in my case, the data is for temperature, wet-bulb temperature, wind speed, and pressure over several years for data taken every hour each day) themselves.

What I'd like to do is estimate equations approximating these different values, "test" then against the data by plotting the equations and their data at various resolutions of time and years (sometimes plotting all the years over top of one another by day-of-year, some times looking at min-max and average data for the month, etc. Then, re-edit the equations and try again.

Frankly, I'm not sure what I'm going to find, so I don't know what I'll need to do - but I don't want to just look at or re-plot 32,000 data points every time..

Is there an Excel "equation editor" or add-on program that lets you display and plot equations themselves (4th order, 5th 6th order polynominals or the sum of sin and cosine waves for example) without forcing the user to "plot a table" ?

RE: Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

Under the hood Excel takes the table of cells from a spreadsheet and loads them into an array. Then the plot is actually generated from the array.

You can use VBA to create the array and plot it.

But frankly it seems to me to be not worth the effort.

I'm sure how, but I suspect that with the dynamic table features in the latest versions of Excel you could set things up on a spreadsheet to be able to enter the parameters and coefficients that you want to play with to accomplish what you are interested in.

RE: Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

A program like MiniTab will probably do what you want. You're really looking for "main effects" from the data.

You might check and see if they have a demo or limited version available since the main program is pretty expensive but it does a lot of heavy lifting.

RE: Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

(OP)
Give me a few hours to go through those instructions.

RE: Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

That's pretty sick Doug!

RE: Excel: Editing, Plotting and Graphing Equations - Not Tables of Numbers

Excel, out of the box, has curve fitting capabilities, to some limited degree. On the charts, you can right click a data series and use trendline. The same capabilities are available within a sheet.

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

Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

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.

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!