Hi Mike,
The same result as yours was reproduced in my environment: FME 2013 SP4.
The result of the first expression of yours is equal to this:
54.4194194444409 - 54.2462277777831 * 0.1 = 48.9947966666626
My manual calculating result is:
dy = ymax - ymin
= 54.4194194444409 - 54.2462277777831
= 0.1731916666578
dx = xmax - xmin
= -116.760933333319 - (-117.051986111095)
= 0.291052777776002
dx is greater than dy, so the result should be:
dx * 0.1 = 0.0291052777776002
It's different from both of old and new results of your expressions.
I guess @max function compares the arguments as character strings like this:
"54.4194194444409-54.2462277777831"
is greater than
"-116.760933333319--117.051986111095"
in lexicographic order.
@max function returns "54.4194194444409-54.2462277777831", and then the ExpressionEvaluator evaluates this string as an arithmetic expression.
"54.4194194444409-54.2462277777831*0.1"
The ExpressionEvaluator with this expression returns the same result as my manual calculation.
@max(@double(@Value(_ymax)-@Value(_ymin)),@double(@Value(_xmax)-@Value(_xmin)))*0.1
And, the AttributeCreator with this expression as "Value" also creates the correct value.
@Evaluate(texpr eexpr max(@Value(_ymax)-@Value(_ymin),@Value(_xmax)-@Value(_xmin))]*0.1])
Anyway, I think @max function should interpret its arguments as numeric values or arithmetic expressions, since it's categorized as one of the FME Math Functions.
I think this is a serious issue for all FME users. I'd like to contact Safe support, may I use your example?
Takashi
Simple test:
The ExpressionEvaluator with this expression returns 1 (NG).
@Evaluate(@max(-(-5),1))
This returns 5 (OK):
@Evaluate(@max(@int(-(-5)),1))
I tested a little more. It seems sure that FME Math Function max and min compare arguments as character strings in lexicographic order when the argument is an expression.
For example, these expressions return unexpected results.
@Evaluate(@max(-(-5),1)) -> returns 1
@Evaluate(@min(-(-5),1)) -> returns 5
@Evaluate(@max(1+0,0+5)) -> returns 1
@Evaluate(@min(1+0,0+5)) -> returns 5
Tease expressions return correct results.
@Evaluate(@max(@int(-(-5)),@int(1))) -> returns 5
@Evaluate(@min(@int(-(-5)),@int(1))) -> returns 1
@Evaluate(@max(@int(1+0),@int(0+5))) -> returns 5
@Evaluate(@min(@int(1+0),@int(0+5))) -> returns 1
I'll request the Safe support with the examples above. After receiving the answer, I'll report here.
Thanks so much Takashi - yes, please submit whatever you need.
Mike
Hi Mike,
I received this answer from Safe support: "This is a bug in the ExpressionEvaluator and other similar transformers which has now been fixed and should be in the next FME 2014 betas - likely builds 14183+. I will post a note to the FME Community once I have verified the fix." Concluding, your expressions are correct, but you encountered the bug unfortunately...
As a present workaround, I think this expression is effective. @max(@double(@Value(_ymax)-@Value(_ymin)),@double(@Value(_xmax)-@Value(_xmin)))*0.1
Takashi
Hi Mike and Takashi,
This has been fixed in FME 2014 betas and also a hot-fix for FME 2013 SP4, build 13547. @Evaluate(@max(-(-5),1)) now correctly returns 5 and not 1.
Cheers,
Dan
Hi,
I confirmed the max / min function in the newest FME 2013 SP4 (Build 13547) returns the expected values in all cases I tested.
Dan, thank you for the fixing and notification.
Takashi
