Problem Plotting Functions

#1 Опубликовано: 08.07.2023 02:43:26

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My Mathcad brain causes me to misunderstand some SMATH syntax. The is especially true in XY-Plots. I have created two function: F(s) and F1(s), which is discontinuous. If I redefine the functions as vectors and use augment to define the x-axis, the plots look okay. However, when I try to plot just the function, it does not work. These plots do not create a trace list as with the vector versions. F(s) just doesn’t plot. F1(s) also doesn’t plot, plus it gives an error.

In short, how do I plot simple functions?

Any help is appreciate, as always.

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Reg CurryLoveland, CO

#2 Опубликовано: 08.07.2023 03:33:26

Alvaro Diaz Falconi

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Hi JReg. If I'm not wrong, just try to plot both with an undefined variable like F(so) and F1(so). The problem is that 's' is a vector.

Best regards.

#3 Опубликовано: 08.07.2023 07:28:35

RegRetired

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Razonar,
Thanks much. That works.

Hope you don't mind if I have a second question.

In this attached sm file, I calculate the solution to an ODE with those two driving functions. Note the last integral in the solution. If I use F(s) it works; however, F1(s) is the function I want in the integral. For some reason it does not work. You will have to change F to F1 in that last integral to see that it fails.

Have I missed something obvious?

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#4 Опубликовано: 08.07.2023 10:39:50

StvMath

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It works if you define F1 as: F1(z):=(M*(z-tstart)+Fexp(tstart))*(z≤tfinish)+Fexp(tfix)*(z>tfinish)

i.e. using Boolean values: (z≤tfinish) = 1 if true, 0 if false, etc.

Don't know why SMath has a problem integrating if.. else.. structures.

#5 Опубликовано: 08.07.2023 13:45:07

RegRetired

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Thanks. I’ll give that a try.

Reg CurryLoveland, CO

#6 Опубликовано: 08.07.2023 15:56:23

RegRetired

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Wrote
It works if you define F1 as: F1(z):=(M*(z-tstart)+Fexp(tstart))*(z≤tfinish)+Fexp(tfix)*(z>tfinish)

i.e. using Boolean values: (z≤tfinish) = 1 if true, 0 if false, etc.

Don't know why SMath has a problem integrating if.. else.. structures.

Thanks again. That really helped.

Reg CurryLoveland, CO

#7 Опубликовано: 09.07.2023 07:45:20

Jean Giraud

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Don't know why SMath has a problem integrating if.. else.. structures.

Smath integrates if/otherwise discontinuous functions.
Bolean must be specified completely, if NOT navigates.

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#8 Опубликовано: 10.07.2023 04:22:25

Вячеслав Мезенцев

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Due to the implementation features, you can't use the function argument the same way you do it in Mathcad. The component allows you to use a vector variable if you add a tilde before the name.

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Problem Plotting Functions - Cannot plot function - Сообщения