Hi. I am trying to set ranges of variables in a plot in Mathcad prime v.7.0. But it is really difficult for me. Can you give me some advice? Thank you so much.
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Your goal is to limit the lines to duplicate the picture, right?
It may be possible doing so with a couple of range variables (I guess you would need four different ranges to accomplish the task), but I find it more comfortable to define new functions using the if-function to "plot" NaNs where you don't want to see the line.
I added Eq1 which was missing in your plot.
EDIT: Just for fun I added a way to achieve the same plot using four ranges.
Your goal is to limit the lines to duplicate the picture, right?
It may be possible doing so with a couple of range variables (I guess you would need four different ranges to accomplish the task), but I find it more comfortable to define new functions using the if-function to "plot" NaNs where you don't want to see the line.
I added Eq1 which was missing in your plot.
EDIT: Just for fun I added a way to achieve the same plot using four ranges.
I am not sure what you problem is!? What your "before" pic is showing would not work in real good old Mathcad as well!
A numerical evaluation of a function definition is not allowed - for good reasons!
You should also be aware that if you define a range and follow that definition by a numerical evaluation, as you did when you defined "t", the range is turned into a vector! This is an undocumented feature and works the same in Mathcad 14/15 as well as in Prime.
That said you also should be aware that the results you get when you evaluate y(t) are NOT the results you might expect!
Because t is now a vector, e^-t is a vector, too, and the same applies to cos(5t). These two vectors are now multiplied and the result is a SCALAR (vector product)! This scalar is now multiplied with cos(10t) which again is a vector and thats the reason you get a vector result, but with values you did not expect.
The get the correct results you would have to apply vectorization when you call y(t).
You will see the very same behaviour in Mathcad 15, 14 as in Prime in this case.
So, no, this is not a bug, but just a matter of misunderstanding how Mathcad and Prime are working and dealing with ranges and vectors.
It looks to me that you mix up formal and actual argument of a function. Its the same in Mathcad/Prime as its in pure Math (and also similar to function definitions in most program languages.
If you look at the simple example below, x in the function definition f(x):=... has nothing to do with the x defined before. Its just the formal argument in the definition of the function and it would work the same if you use a different argument name here as can be seen in the second picture.
On contrary the x in the evaluation is the actual/current function argument and Mathcad uses the variable with that name when you evaluate the function or will give you an error if no variable x is defined.
Look again at the second where I used "t" as formal function argument. If you would put an eval equal sign after the definition, why should Mathcad use the variable "x" here? Formal function arguments can be named as you like and have no connection whatsoever with variables of the same name defined elsewhere.
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Concerning your criticism about Prime I fully agree, though. Its a shame that 15 year old Mathcad still is superior over its successor(?). Prime is slower, more awkward to handle is missing a lot of features available in old Mathcad and when it comes to plotting ... OMG!! And Prime sure has its bugs, but what you showed is not a bug, its normal behaviour even though you seem to find it not intuitive.
Thanks for your reply, I typically have only used algebraic equations, range variables, graphing, derivatives and integrals.
For most of my other needs I use other software packages to further process the data (OriginPro, for example).
The issue I found when you responded the first time helped identify that my previous worksheets where I typically asked for the evaluation of the range variable, along with the actual variable was from older versions before the = sign was allowed to be used at all.
I have been using MathCAD for ~27 years, so I typically only use it for the above basic functions, most notably, units calculation which was seriously damaged on my converted worksheets.
I have been used to the attached image for the issue I was having trouble with, because I was used to doing it the old way (v15 and prior).
It mixed the two images up, but on the left is what I started doing when they allowed the = sign to be done after the range variable. In my original reply, I mis-typed 'range variable' when I should have put the 'function' using the 'range variable', as I later realized. Below you can see how I now have been using the range variable evaluation, and on the right, the old way I did it to get an X, Y type of comparison next to each other.
I understand the mathematical difference of the variable vs. function, I had just done it more recently on new worksheets evaluating the range variable immediately after defining it, so I figured it would allow me to do the same after the function definition, similarly. Now I see my old worksheets had both next to each other but not immediately after the definition like I now do more regularly.
