subtract 2 numbers

[jbegleyc]

I am new to Jasper Reports and I am trying to put togather my first report. All I want to do is create a variable that subtracts 2 numbers:

 

$F{actual}-$F{forcast}

 

I can not seem to get this to work and can not find any examples. I keep getting a compile error:

 

'- operator invalid for java.lang.Double'

 

what could I be doing wrong here?

[Teodor Danciu]

Hi,

 

Note that those should be valid Java expressions.

And in Java you cannot subtract Double ojects just like that (unless you are using JDK 1.5 syntax).

 

So, you either try:

 

new Double($F1{actual}.doubleValue() - $F2{}.doubleValue(forcast))

 

Or, you could learn how to config the JDT compiler for 1.5 compatibility here:

 

http://sourceforge.net/mailarchive/forum.php?thread_id=8390023&forum_id=7912

http://sourceforge.net/mailarchive/forum.php?thread_id=8391557&forum_id=7912

http://sourceforge.net/mailarchive/forum.php?thread_id=8401091&forum_id=7912

 

Another approach would be to use the Groovy compiler.

Check the supplied /demo/samples/groovy sample in our project distribution to see how simplified expression syntax could be used thanks to the Groovy language.

 

I hope this helps.

Teodor

[jbegleyc]

Teodor,

 

Funny thing is I thought I had tried that before but it didn't work. It worked when I did it this time though so I must have typed something wrong.

 

Thank you for your help and I will check out the Groovy compiler when I get a chance.

 

Jeff