I can't understand example in wiki "Multiple User Defined Statistic In nGrinder"

[kdw9502]

# -*- coding:utf-8 -*-

# A simple example using the HTTP plugin that shows the retrieval of a
# single page via HTTP.
#
# This script is auto generated by ngrinder.
#
# @author admin
from net.grinder.script.Grinder import grinder
from net.grinder.script import Test
from net.grinder.plugin.http import HTTPRequest
from net.grinder.plugin.http import HTTPPluginControl
from java.util import Random

control = HTTPPluginControl.getConnectionDefaults()
# if you don't want that HTTPRequest follows the redirection, please modify the following option 0.
# control.followRedirects = 1
# if you want to increase the timeout, please modify the following option.
control.timeout = 6000

test1 = Test(1, "Test1")
request1 = HTTPRequest()

#grinder.statistics.registerDataLogExpression("Delivery time", "userLong0")
grinder.statistics.registerSummaryExpression("User_defined", "(/ userLong0(+ (count timedTests)))")

# Make any method call on request1 increase TPS
test1.record(request1)
random = Random()

class TestRunner:
    # initlialize a thread
    def __init__(self):
        grinder.statistics.delayReports=True
        pass

    # test method      
    def __call__(self):
        result = request1.GET("http://www.naver.com")

        # do something
        deliveryTime = random.nextInt(1000)
        grinder.sleep(deliveryTime)
        grinder.logger.info("deliveryTime: %d" % deliveryTime)
        grinder.statistics.forLastTest.setLong("userLong0", deliveryTime)

        if result.getStatusCode() == 200 :
            grinder.statistics.forLastTest.success = 1
        elif result.getStatusCode() in (301, 302) :
            grinder.logger.warn("Warning. The response may not be correct. The response code was %d." %  result.getStatusCode())
            grinder.statistics.forLastTest.success = 1
        else :
            grinder.statistics.forLastTest.success = 0

In this example, registerSummaryExpression register expression (/ userLong0(+ (count timedTests))).
As far as I know, the expression is post-fix format and "count timedTests" means how many test is,
then the expression as infix is userlong0/ ((count timeTests) + ) <- isn't it invalid? append nothing?

[donggyu04]

@kdw9502

Refer to the grinder's guide.

[kdw9502]

I already read that, but can't understand what does that append nothing means

[imbyungjun]

infix is invalid

[kdw9502]

제 말은, 예시코드의 prefix expression을 infix로 바꿔보면 저런데, prefix expression도 틀린게 아니냐는거죠

[imbyungjun]

You're right. The example has an error. The example in Wiki have to be ammended like below.

맞네요. 예시가 잘못되었습니다. Wiki 예시는 아래와 같이 수정되어야합니다.

"(/ userLong0(+ (count timedTests) untimedTests))"