A Small Bug in Differential Equations Display

A Small Bug in Differential Equations Display - Messages

#1 Posted: 6/16/2018 3:43:24 PM
Przemyslaw D. GACIA

Przemyslaw D. GACIA

4 likes in 11 posts.

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I found small bug in Differential Equations Display.
Simple example:
2018-06-16 Capture.PNG

Calculations are done. But symbolic evaluation do not show the outcome.
The problem is not catastrophic. But I thought it worth it to report it.
#2 Posted: 6/16/2018 9:59:33 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Wrote

Calculations are done. But symbolic evaluation do not show the outcome.
The problem is not catastrophic. But I thought it worth it to report it.



Confirmed: no bug ... your screen is lazy to expand ... if that what you have !

Diff2.PNG
#3 Posted: 6/17/2018 6:58:08 AM
Przemyslaw D. GACIA

Przemyslaw D. GACIA

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Group: User

Jean, you misunderstood the "problem".

Not the calculation is wrong.
This is:
2018-06-17 - Capture.PNG

As I wrote, it is not big and not a kind it is impossible to live with it.
I am just reporting what I notice.
#4 Posted: 6/17/2018 10:32:25 AM
Jean Giraud

Jean Giraud

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Wrote

As I wrote, it is not big and not a kind it is impossible to live with it.
I am just reporting what I notice.


There is no use to evaluate the Mathcad style. On the other hand,
many direct expansion Mathcad style can't be copied for export.
Thus, the best is the algorithmic construction. On that point,
Smath is fully competent ... look @ the "Colibri" attached.

Jean

DiffAlgo.PNG

Spline De Boor [Colibri].sm (34 KiB) downloaded 34 time(s).
#5 Posted: 6/17/2018 6:31:04 PM
Jean Giraud

Jean Giraud

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There are few more curiosities in Smath.
In Smath, erf(x) is not a scalar function in the maths sense,
Build the example
and if you get the two red ones, "X-not defined"
that you must read "erf(x) is not scalar" ... Thus:
1. vectorize the integrand
2. Pre-assign the X_Y plot
Example from version 6179

Derf.PNG
#6 Posted: 6/17/2018 6:53:50 PM
Andrey Ivashov

Andrey Ivashov

2269 likes in 3734 posts.

Group: Super Administrator

Thank you, [USERLINK]PDG[/USERLINK].

Bug confirmed. Will look at it later.
#7 Posted: 6/17/2018 7:08:08 PM
Przemyslaw D. GACIA

Przemyslaw D. GACIA

4 likes in 11 posts.

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I thank you Andrey.
I use SMath almost 10 years now.
Univ., Research, PhD, now at side projects.

Great tool. Great work.
#8 Posted: 6/17/2018 8:31:41 PM
Jean Giraud

Jean Giraud

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Wrote

I am just reporting what I notice.



That one, X_Y refuses plotting at all !

DerivGamma.PNG
#9 Posted: 6/17/2018 11:23:28 PM
Jean Giraud

Jean Giraud

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Wrote

Jean, you misunderstood the "problem".



I accept, but in turn you must accept the fundamental
concept of transit algorithm in integration/derivation.
Good thing it is this way, otherwise lot more advanced maths
could not be done or would issue errors messages of all kinds.
... light red page 4.

Jean

Maths_0 Transit [The concept].sm (76 KiB) downloaded 35 time(s).

#10 Posted: 6/17/2018 11:53:48 PM
Jean Giraud

Jean Giraud

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Wrote

transit algorithm


... this is another style of parametric solution.

ODE_Laplace 1rst [Type 1].sm (24 KiB) downloaded 37 time(s).
#11 Posted: 6/18/2018 12:32:23 AM
Jean Giraud

Jean Giraud

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Wrote

... this is another style of parametric solution.



... a much different style of transit.
At that times my brain diluted on that one !
Takes quite a while before "t_not defined"

Jean

TransitAdvanced.PNG

Integrate Voltera IntEQUATION.sm (28 KiB) downloaded 40 time(s).
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