xy plot - undefined variable

[dagi]

Hi 

My problem is to plot angular velocity as function of time. I get the message "this variable is undefined. Check that the label is set correctly" for the variable t - well - it's a variable defined in the function? - 

Tips would be much appreciated.

[DJF]

Sometimes mathcad needs its plotting range defined.  Usually it will default to -10 to +10 but sometimes it doesn't.  Not sure why.  Anyway, just give it a range variable for t.

t:=0s,0.01s,1s

[dagi]

thanks 🙂

[Fred_Kohlhepp · Accepted solution]

In this instance "t" needs to have units of time to balance the equation.

[Werner_E]

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@DJF wrote:

Sometimes mathcad needs its plotting range defined. 

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To be specific: You can't use the quickplot feature with units. You need to define a range for the abscissa values whenever you have to assign units to them. Keep in mind that when defining a range with units, its mandatory to provide the second value. Something like t:=0s .. 100s won't work.