Symbolic calculation versus numeric calculation

Symbolic calculation versus numeric calculation - Messages

#1 Posted: 2/6/2009 10:17:05 AM
sleschke

sleschke

0 likes in 13 posts.

Group: User

Hello Smath,

I would like to thank you too for providing such a great program.
When I tried some basic calculation I found some inconsistance
in the way a term is evaluated.

If I try: π/6 + π/6 ->
I will get 12π/36.
By using the menu this can be simplified to π/3

If I assign: X1:=π/6 X2:=π/6
and try: X1 + X2 ->
I will get 7440786129085100/7105427357601000

I would have expected the same result like in the direct calculation.

I had a similar effect when calculating a definite integral
from -π/6 to +π/6 of cos(x)dx I will get the result 1.
If I do the same integral for √2*cos(x)dx I will get 7071/5000

In general I would say that results should stay symbolic as far as possible.
It would also be nice if results would already be simplified as far as possible.
#2 Posted: 2/6/2009 11:23:45 AM
Andrey Ivashov

Andrey Ivashov

2269 likes in 3729 posts.

Group: Super Administrator

Thank you for the reports.
Wrote

when calculating a definite integral
from -π/6 to +π/6 of cos(x)dx I will get the result 1.
If I do the same integral for √2*cos(x)dx I will get 7071/5000


This happens because definite integrals program can evaluate only in numeric, that's why we can't fix it now. But I'll remember it for the future.
Wrote

If I assign: X1:=π/6 X2:=π/6
and try: X1 + X2 ->
I will get 7440786129085100/7105427357601000


Thanks for this finding, will try to fix it till next release.
#3 Posted: 2/6/2009 6:21:14 PM
Andrey Ivashov

Andrey Ivashov

2269 likes in 3729 posts.

Group: Super Administrator

One of the issues fixed:


Will be available in the next version of SMath Studio. Thank you once again
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