×
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.

# Does anyone know how to fix this....

## Does anyone know how to fix this....

(OP)
I don't understand that "must be an scalar", the number is already an scalar!

### RE: Does anyone know how to fix this....

Hello,

your second variable "rho" is a matrix with the dimension 1x1 and no skalar (because it stands in brackets).

The easiest way to fix this, is to define a new variable like this: p = r[0,0

That extractes the 0,0-element from this matrix and writes it to a scalar variable.

That would work but I think, your mistake is in the calculation before, rho shouldn't be a 1x1-matrix. This occurs if you multiple a 3x1 with a 1x3 matrix as vectorproduct. Instead of this you can use the scalarproduct (3x1)^T * (1x3). But there may be other possibilities.

Sorry for bad spelling, I've only spare time.
Christian

(OP)

### RE: Does anyone know how to fix this....

(OP)
I also tried to fix it with the solution that you gave me, but i don't understand it, is:

p = r[0,0

Now, i tried to write that but nothing happend, gave me an error, can you take a picture of that, like an example or something?

Thanks!

### RE: Does anyone know how to fix this....

Your problem starts with the definition of d, since its result shows up with a parenthesis around a single number, indicating a 1-D vector.

The simplest solution is to select the end of the definition of d and tack on [0.  Since the vector is 1-D, [0,0 results in an error.

TTFN

### RE: Does anyone know how to fix this....

The problem is that the vlookup function returns a vector.

#### Quote:

vlookup(z, A, c) Looks in the first column of a matrix, A, for a given value, z, and returns the value(s) in the same row(s) in the column specified, c. When multiple values are returned, they appear in a vector.
Apparently when a single value is returned, it appears in a one row vector.

IRstuff's solution should work.

### RE: Does anyone know how to fix this....

(OP)
HEY!!, that's perfect!!!, worked  BEAUTIFUL!!!

Thanks very much!!!

here it is........

#### 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.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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!