calulate with math operators and Variables

[Gerald Weis]

I have written an Maro with the follow defininitions

\define Benzkauf2(Datum kmalt kmneu getankt Gesamtpreis)
<tr align=right>
    <td>$Datum$</td>
    <td>$kmalt$</td>
    <td>$kmneu$</td>
    <td>$getankt$</td>
    <td>$Gesamtpreis$</td>
    <td>[[$kmneu$ $kmalt$ substract[]]</td>
    <td>[[$getankt$]multiply[100]divide[[$kmneu$ $kmalt$ substract[]]]</td>
    <td>[[$Gesamtpreis$]divide[$getankt$]]</td>
</tr>
\end

but the caltulating do not work.

It shoud do so

1. kmneu - kmalt

2. getankt * 100 / (kmneu - kmalt)

3. Preisgesamt / getankt

how i can do it

thanks for help

[Mat]

Looking at the documentation example for subtract

[[$kmneu$ $kmalt$ substract[]]

should probably be

[[$kmneu$]subtract[$kmalt$]]

And you type

 <td>[[$Gesamtpreis$]divide[$getankt$]]</td>

but you state

3. Preisgesamt / getankt

i.e another name for the variable

<:-)

[Mat]

Note also that thing is calculated just because it's within brackets like that. If you want the expression evaluated it must also be enclosed in triple braces like so:

{{{ [...] }}}

<:-)

[Gerald Weis]

{{

Hello Mat,

i was trying your solutions.

i have read the dokumentation in tiddlywiki.com.

<td>{{{[[$kmneu$]subtract[$kmalt$]]}}}</td>

<td>{{{[[$Gesamtpreis$]divide[$getankt$]]</td>}}}

thats work

thanks

Only this dont work

<td>{{{[[[$getankt$]multiply[100]]divide[$kmneu$ substract[$kmalt$]]}}</td>

Its calculatete the equations, but not the solution of both.

its mean

1. {{{[[[$getankt$]multiply[100]]}}

2. {{{[$kmneu$ substract[$kmalt$]]}}

thats what my equation do

its dont divide

[Eric Shulman]

On Monday, February 17, 2020 at 10:51:15 PM UTC-8, Gerald Weis wrote:

<td>[[$kmneu$]subtract[$kmalt$]]</td>

<td>[[[$getankt$]multiply[100]]divide[[$kmneu$ $kmalt$ substract[]]]]</td>

<td>[[$Gesamtpreis$]divide[$getankt$]]</td>

 

You are using the wrong kind of outer brackets.

To *evaluate* a filter, use tripled curly braces around the entire filter expression.  Also, you can't "nest" filters, so use a variable to hold the result of the first calculation, and then reference that variable in the second calculation.

Finally, *after* computing the desired values, reference the variables to produce the output.

Thus:

\define Benzkauf2(Datum kmalt kmneu getankt Gesamtpreis)

<$vars v1={{{ [[$kmneu$]subtract[$kmalt$]] }}}>
<$vars v2={{{ [[$getankt$]multiply[100]divide<v1>] }}}>
<$vars v3={{{ [[$Gesamtpreis$]divide[$getankt$]] }}}>

<tr align=right>
    <td>$Datum$</td>
    <td>$kmalt$</td>
    <td>$kmneu$</td>
    <td>$getankt$</td>
    <td>$Gesamtpreis$<

/td>
    <td><<v1>></td>
    <td><<v2>></td>
    <td><<v3>></td>
</tr>
</$vars>
</$vars>
</$vars>
</tr>
\end

That should do what you want.  Let me know how it goes.

enjoy,

-e

Eric Shulman

TiddlyTools.com: "Small Tools for Big Ideas!" (tm)

InsideTiddlyWiki - http://www.TiddlyTools.com/InsideTW/

[Gerald Weis]

Hallo Eric,

i have tested it.

Its works fine.

now i have trying to round it on 2 or 3 Digits behind the decimnalpoint.

i dont find it.

thankyou

[Eric Shulman]

On Tuesday, February 18, 2020 at 1:42:04 AM UTC-8, Gerald Weis wrote:

now i have trying to round it on 2 or 3 Digits behind the decimnalpoint.

i dont find it.

TW Math filters include round[], trunc[], ceil[], and floor[]... any of which can be used to remove the decimal part of a number

To retain given number of decimal places, you would first multiply by a power of 10 (to shift the decimal place to the right), then apply round[] (or any of the other similar filters), and then divide again by the same power of 10 to shift the decimal place back to its original position in the number.  Thus:

<$vars v3={{{ [[$Gesamtpreis$]divide[$getankt$]multiply[1000]round[]divide[1000]] }}}>

will round the number to 3 decimal places.

enjoy,

-e

[Gerald Weis]

You are top

thanks