kapacitor tickscript won't work after adjustment

I adjust tickscript(kapacitor) for my calculation. However, no alerts work after few changes. Before adjustment, it worked without problem. I wonder why it does not work after adjustment. To be more specific, I need to get "MACD" of my stock price. Measurements contain the price of each items. Anyone knows why?

before it was:

var db = 'telegraf'

var rp = 'autogen'

var measurement = 'exec'

var groupBy = ['symbol']

var whereFilter = lambda: TRUE

var name = 'coin'

var idVar = name + '-{{.Group}}'

var message = ' {{.ID}} {{.Level}} {{.Time}}'

var idTag = 'alertID'

var levelTag = 'level'

var messageField = 'message'

var durationField = 'duration'

var outputDB = 'chronograf'

var outputRP = 'autogen'

var outputMeasurement = 'alerts'

var triggerType = 'threshold'

var crit = 50000000000

var data = stream
    |from()
        .database(db)
        .retentionPolicy(rp)
        .measurement(measurement)
        .groupBy(groupBy)
        .where(whereFilter)
    |eval(lambda: "lastPrice")
        .as('value')

var trigger = data
    |alert()
        .crit(lambda: "value" > crit)
        .message(message)
        .id(idVar)
        .idTag(idTag)
        .levelTag(levelTag)
        .messageField(messageField)
        .durationField(durationField)
        .stateChangesOnly()
        .telegram()
        .chatId('####')
        .parseMode('Markdown')

trigger
    |eval(lambda: float("value"))
        .as('value')
        .keep()
    |influxDBOut()
        .create()
        .database(outputDB)
        .retentionPolicy(outputRP)
        .measurement(outputMeasurement)
        .tag('alertName', name)
        .tag('triggerType', triggerType)

trigger
    |httpOut('output')

Now it became:

var db = 'telegraf'

var rp = 'autogen'

var measurement = 'exec'

var groupBy = ['symbol']

var whereFilter = lambda: TRUE

var name = 'coin'

var idVar = name + '-{{.Group}}'

var message = ' {{.ID}} {{.Level}} {{.Time}}'

var idTag = 'alertID'

var levelTag = 'level'

var messageField = 'message'

var durationField = 'duration'

var outputDB = 'chronograf'

var outputRP = 'autogen'

var outputMeasurement = 'alerts'

var triggerType = 'threshold'

var crit = 0

var data = stream
    |from()
        .database(db)
        .retentionPolicy(rp)
        .measurement(measurement)
        .groupBy(groupBy)
        .where(whereFilter)
    |eval(lambda: "lastPrice")
        .as('v')

var avg12 = data
    |window()
        .period(3m)
        .every(1m)
    |mean('x1')
        .as('x1a')

var avg26 = data
    |window()
        .period(5m)
        .every(1m)
    |mean('x2')
        .as('x2a')

var macd = avg12
    |join(avg26)
        .as('x1a', 'x2a')
    |eval(lambda: float('x1a.value' - 'x2a.value'))
        .keep()
        .as('value')

var trigger = macd
    |alert()
        .crit(lambda: "value" > crit)
        .message(message)
        .id(idVar)
        .idTag(idTag)
        .levelTag(levelTag)
        .messageField(messageField)
        .durationField(durationField)
        .stateChangesOnly()
        .telegram()
        .chatId('###')
        .parseMode('Markdown')

trigger
    |eval(lambda: float("value"))
        .as('value')
        .keep()
    |influxDBOut()
        .create()
        .database(outputDB)
        .retentionPolicy(outputRP)
        .measurement(outputMeasurement)
        .tag('alertName', name)
        .tag('triggerType', triggerType)

trigger
    |httpOut('output')