Evaluate expression for a variable(s) set to a number

#1 Опубликовано: 10.04.2014 16:26:17

127 сообщений из 494 понравились пользователям.

Группа: Moderator

Hi All,

So I am using Smath Studio for personal projects (I am converting from Mathematica that I no longer have access to).

Here is a very simple task i need to do and yet after 30 minutes of search I still do not know how to achieve it:

Say I have g=h+j-k+100

How do I evaluate g for h = 1, j=2, k=3?

I have found that if g=j+2, setting g(j)=g will do the trick for one variable only: g(1)=3, while g=j+2.

In mathematica it would be as simple as g/.{h->1,j->2,k->3}

This would come in very useful if you would want to evaluate function that has more than one variable.

Many thanks!

#2 Опубликовано: 10.04.2014 17:46:56

Alexander O. Melnik

127 сообщений из 494 понравились пользователям.

Группа: Moderator

Thank you ioan92! That is really what I needed.

Also what would be the best tutorial you can recommend on SMATH? Either English or Russian.

Thanks!

#3 Опубликовано: 10.04.2014 17:49:40

Martin Kraska

1 230 сообщений из 2 156 понравились пользователям.

Группа: Moderator

The FunctionsExtensions plugin provides the at() substitution function with special operator formatting. This exploits the symbolic storage of the expression in the variable g.

Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx

#4 Опубликовано: 10.04.2014 17:54:11

Alexander O. Melnik

127 сообщений из 494 понравились пользователям.

Группа: Moderator

That looks very interesting as well, will experiment. Thanks!

#5 Опубликовано: 17.04.2014 10:36:20

Alexander O. Melnik

127 сообщений из 494 понравились пользователям.

Группа: Moderator

Hi everyone!,

Not sure if this would be a bug but at() function does not seem to work while evaluating fuctions that include Min() or Max().

See workbook and photo attached.

Thanks!

2 пользователям понравился этот пост

Martin Kraska 17.04.2014 18:08:00, Davide Carpi 19.04.2014 03:42:00

#6 Опубликовано: 17.04.2014 11:10:56

Martin Kraska

1 230 сообщений из 2 156 понравились пользователям.

Группа: Moderator

Confirmed. This is bug of Min() and Max(). Apparently they always try to return a numeric result, regardles of what the optimization setting is. If they would return themselves with evaluated/preprocessed arguments, at() would work, as the example with max() shows.