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M
Marius_P10-Marble
10-Marble
July 4, 2023
Solved

plotting issue -this variable is undefined

  • July 4, 2023
  • 2 replies
  • 3047 views

Hello,

 

I have some difficulties to plot on a XY axes system, the efficiency of a voltage converter. I want to have on the x-ax the output current in Amps, and on the y-ax the result in % for a specific switching frequency value.

The error that I got is related to the fact that the variable from the x-ax is undefined.

Could you help me please to understand what is wrong?

 

Thank you!

 

 

Best answer by Werner_E

Its not a good idea to omit units as its one of the strengths of Prime to be able to naturally deal with units.

Instead of using Io dimensionless and adding the unit Ampère just when you call the function, you should rather use a range variable with units for Io.

You may also consider formatting the function values as percent instead of multiplying with 100.

For further questions you sure should attach your Prime worksheet (and state which version you are using) instead of posting just pictures.

2 replies

M
MartinHanak24-Ruby III
24-Ruby III
July 4, 2023

Hi,

you picture contains large white area. Please use Snip&Sketch application to get picture of specific screen area.

Also upload Mathcad file if it is possible.

M
Marius_P10-MarbleAuthor
10-Marble
July 4, 2023

Hello Martin,

 

Please find attached the capture using snip & sketch tool.

M
MartinHanak24-Ruby III
24-Ruby III
July 4, 2023

Hi,

also upload Mathcad file if it is possible.

W
Werner_E25-Diamond I
25-Diamond I
July 4, 2023

Because you are using units on variable "Io" you can't use the quickplot feature of Prime.

You have to define a "Io" as a range to be used for plotting in front of the plot. Something like Io:=0A, 0.1A .. 120A.

M
Marius_P10-MarbleAuthor
10-Marble
July 4, 2023

Hello Werner,

 

Yes, I noticed that the units have an influence, and I did a small change, please see it attached.

 

Thank you!

W
Werner_E25-Diamond IAnswer
25-Diamond I
July 4, 2023

Its not a good idea to omit units as its one of the strengths of Prime to be able to naturally deal with units.

Instead of using Io dimensionless and adding the unit Ampère just when you call the function, you should rather use a range variable with units for Io.

You may also consider formatting the function values as percent instead of multiplying with 100.

For further questions you sure should attach your Prime worksheet (and state which version you are using) instead of posting just pictures.

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