field math: field = field + 1

[Dave]

What's the simplest way to do this? 

 I did read about possibly having to install a "spreadsheet" plugin, but surely there is a simple straight foreward way to do addition and subtraction of values in fields...

Thanks,

Dave

[Mohammad]

Look here:

 http://mathmacros.tiddlyspot.com/

Or another version in http://tobibeer.github.io/tb5/#calc

[@TiddlyTweeter]

Or, for basic Math, Telmiger's simple, flexible, RPN plugin, https://tid.li/tw5/plugins.html#%24%3A%2Fplugins%2Ftelmiger%2Frpn. 

[Dave]

That's perfect! 

Thank you :)

[TonyM]

Mohammad,

Have you actually used the one at http://mathmacros.tiddlyspot.com/ the wiki is version 5.1.5  and  Is not working out of the box in 5.1.17

Regards

Tony

[Mohammad]

Tony!

 The modified one is in Tobias Beer tb5 and it works. The TW version there is 5.1.13

http://tobibeer.github.io/tb5/#calc

/Mohammad

[Dave]

Okay, I'm trying to subtract one field from another

field "due" is 20181112

and field "mynow" is 20181106

this works:

<<calc !!due -1>>

to give 20181111

but I've tried this

<<calc !!due -!!mynow>>

and this

<<calc !!due - !!mynow>>

and this

<<calc !!due -<$view field="mynow"/> >>

and I either get "20181112" as the result, or NaN

Is the calc macro only able to calculate with a single field?

[TonyM]

Dave,

I think you must use a text reference {{!!fieldname}} or fieldname

But never a !!fieldname

Check the calc doc and look for an example.

Tony

[Dave]

Found it!

this works

<<calc !!due -  by:!!mynow>>

I had skipped that previously because I though "by" indicated something else, but it actually is:

a value or a TextReference serving as the operand if the operation does not define any