Hi
Say I have an expression:
Z(s):= c(s)[a(s)+b(s)]; where s is a variable
When I evaluated them, they are not the same.
Z(s)=
The results is not the same as:
c(s)[a(s)+b(s)]=
Please see attached for a better explanation. The bottom right row result is not the same as the bottom left result. Bottom right row is correct
I think it has to do with some kind of matrix errors
Thanks
Rdliquid
Solved! Go to Solution.
Your function Z(s) is NOT dependent on "s" but on "freq". If you want it to be dependent on "s" you would have to write
EDIT: The pic showed the wrong expression - replaced it for the correct one.
Did you type the [ ( and the ] ) ?
Then there's your error. You should ONLY type those if you want to make a matrix.
This equation should be typed in as:
c(s)*(a(s)+b(s)).
Success!
Luc
Hi Luc,
Thanks, no that is just an example and I used "[" instead of "(" for easy viewing the equation. Sorry for the confusion. The attachment will clears things up as what I mean.
I think it has to do with scalar and vector quantity.
Re-attaching the file in case it did not attach the first time
Thanks
Rdliquid
Your function Z(s) is NOT dependent on "s" but on "freq". If you want it to be dependent on "s" you would have to write
EDIT: The pic showed the wrong expression - replaced it for the correct one.
Hi Werner_E,
Thanks that's it and it makes sense to me now. Still trying to get comfortable with Mathcad 6
Thanks a lot!
Rdliquid
Have a follow up question on this topic,
Do you know why I can not give a variable "s" in Zin1(s)?
As you can see from below, Zin1(s) give me a unit error and yet Zin2 without variable "s" does not give me any errors? Zin1(s) should be correct since the right side of it depends on "s" right?
Thanks a lot for your helps
Rdliquid
The error message does not make sense and is misleading.
With Z.in2 you are defining a function, not an expression which you can evaluate as in Z.in2.
So simply delete the equal sign after the definition of the function.
When you define Z.in1(s), the s is the formal function argument and has nothing to do with the vector s you defined before. In the second expression in the pic I evaluate the function with the vector s as actual argument.
You could define the function using a completely different name for the formal argument and it would work the very same way. In the pic below I used sigma as formal argument name:
BTW, do you know that you can setup the sheet so that every result shows the imaginary unit as "j" and not as "i"?
Hi Werner_E,
Thanks a lot for your helps. It makes sense to me now.
I should not evaluate the function Zin1(s) after I defined it on the same line. After I moved down to the next line and evaluated Zin1(s) with the "=" sign and it works!
The reported error caused a lot of confusion for me and I was looking at a different area of the problem and I was unable to figure it out.
Also I did not know that "the s is the formal function argument and has nothing to do with the vector s you defined before". Thanks for that information as well
Not sure about the sheet set up but I am comfortable with using "i" as an imaginary number since school and just do not want to change.
Thanks again,
Rdliquid
If you are happy with "i" thats OK. I just thought to mention that you can change it to "j" throughout as its usual in electro techniques. I also noticed that you used "j" yourself when you defined s or Z(s), etc.