Evaluating an expression within a command string in a palette

Does anyone know how to evaluate an expression in a command string for a palette.

I have saved a value in the system variable USERR5 and when I click on a button in a palette to insert some text I want to set the text height to the value in USERR5 multiplied by a standard value, for example 2 * 1.8.

I've tried wrapping the expression with brackets and quotation marks, but I still get an error message that says a numerical value is required to set the text height.

Somewhere I've seen how to do it but can unfortunately I can't find it anymore.

Maybe with a lisp expression:

 (* 2 (getvar "userr5"))

Try it in the command line first, for sure it returns a number.

Thanks Fuccaro, that works just fine. I think it was a mental block because its just simple LISP

Just a suggestion (* 2 (getvar "userr5")) change to (* 2.0 (getvar "userr5")) sometimes a 2* will return an integer answer v's 2.0 returns a real answer. Just a frustrating thing about programing in lisp.

May have an effect if you want 3.5 high text not 4.

Just a suggestion (* 2 (getvar "userr5")) change to (* 2.0 (getvar "userr5")) sometimes a 2* will return an integer answer v's 2.0 returns a real answer.

Point taken BigAl, thanks.

Just to round things off:

I have a palette on which I have various buttons where I can select which scale to use, ie. 1:500, 1:250, 1:100 etc. The command string for such a button is:

^C^Cltscale;0,5;regen;userr5;0.5;modemacro;"Scale 1:500;

It sets the LTSCALE, writes the value 0.5 to the system variable USERR5 and displayes the scale I have selected next to the coordinate display bottom left.

I then have another button where I insert som text which must be a certain size and style. The command string for such a button is:

^C^Ctextsize;$M=(* 4.0 $(getvar,userr5));_dtext;_style;12_Flrstk;\;270;

This sets the text height using a standard size multiplied by the value saved in USERR5 by the scale button above, issues the DTEXT command, selects the style and in this case sets the angle of the text (if you want to set the text angle by user input replace the 270 with a \ ).

I'm going to insert blocks from buttons and scale them in a similar fashion.

An advantage with this method is that you can set the size of text and blocks differently within one drawing. Using annotation is not always wanted and we have some funny clients :wink:.

Comments and improvements are welcome.

Well, yes. I missed that 2.0 thing. Thanks Bigal for your contribution!