Could someone help me? I want to use selector in self.EMA(symbol, period, resolution, selector).

I am using and I dont know how to use selector. I have tried data.Close Data.Close self.Data.Close only close. In Api I dont find exact information or I dont understand it.There is written:

QuantConnect.MarketDataTypeMarket Data Type of this data - does it come in individual price packets or is it grouped into OHLC.




# QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
# Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

from clr import AddReference

from System import *
from QuantConnect import *
from QuantConnect.Algorithm import *
from QuantConnect.Brokerages import *
from QuantConnect.Orders import *

import decimal as d

### <summary>
### The demonstration algorithm shows some of the most common order methods when working with Crypto assets.
### </summary>
### <meta name="tag" content="using data" />
### <meta name="tag" content="using quantconnect" />
### <meta name="tag" content="trading and orders" />
class BasicTemplateCryptoAlgorithm(QCAlgorithm):

def Initialize(self):
'''Initialise the data and resolution required, as well as the cash and start-end dates for your algorithm. All algorithms must initialized.'''

self.SetStartDate(2018, 4, 4) #Set Start Date
self.SetEndDate(2018, 4, 4) #Set End Date

# Although typically real brokerages as GDAX only support a single account currency,
# here we add both USD and EUR to demonstrate how to handle non-USD account currencies.
# Set Strategy Cash (USD)

# Set Strategy Cash (EUR)
# EUR/USD conversion rate will be updated dynamically
self.SetCash("EUR", 10000)

# Add some coins as initial holdings
# When connected to a real brokerage, the amount specified in SetCash
# will be replaced with the amount in your actual account.
self.SetCash("BTC", 1)
self.SetCash("ETH", 5)

self.SetBrokerageModel(BrokerageName.GDAX, AccountType.Cash)

# You can uncomment the following lines when live trading with GDAX,
# to ensure limit orders will only be posted to the order book and never executed as a taker (incurring fees).
# Please note this statement has no effect in backtesting or paper trading.
# self.DefaultOrderProperties = GDAXOrderProperties()
# self.DefaultOrderProperties.PostOnly = True

# Find more symbols here:
self.AddCrypto("BTCUSD", Resolution.Minute)
self.AddCrypto("ETHUSD", Resolution.Minute)
self.AddCrypto("BTCEUR", Resolution.Minute)
symbol = self.AddCrypto("LTCUSD", Resolution.Minute).Symbol

# create two moving averages = self.EMA(symbol, 30, Resolution.Minute)
self.slow = self.EMA(symbol, 60, Resolution.Minute)

def OnData(self, data):
'''OnData event is the primary entry point for your algorithm. Each new data point will be pumped in here.

data: Slice object keyed by symbol containing the stock data

# Note: all limit orders in this algorithm will be paying taker fees,
# they shouldn't, but they do (for now) because of this issue:

if self.Time.hour == 1 and self.Time.minute == 0:
# Sell all ETH holdings with a limit order at 1% above the current price
limitPrice = round(self.Securities["ETHUSD"].Price * d.Decimal(1.01), 2)
quantity = self.Portfolio.CashBook["ETH"].Amount
self.LimitOrder("ETHUSD", -quantity, limitPrice)

elif self.Time.hour == 2 and self.Time.minute == 0:
# Submit a buy limit order for BTC at 5% below the current price
usdTotal = self.Portfolio.CashBook["USD"].Amount
limitPrice = round(self.Securities["BTCUSD"].Price * d.Decimal(0.95), 2)
# use only half of our total USD
quantity = usdTotal * d.Decimal(0.5) / limitPrice
self.LimitOrder("BTCUSD", quantity, limitPrice)

elif self.Time.hour == 2 and self.Time.minute == 1:
# Get current USD available, subtracting amount reserved for buy open orders
usdTotal = self.Portfolio.CashBook["USD"].Amount
usdReserved = sum(x.Quantity * x.LimitPrice for x
in [x for x in self.Transactions.GetOpenOrders()
if x.Direction == OrderDirection.Buy
and x.Type == OrderType.Limit
and (x.Symbol.Value == "BTCUSD" or x.Symbol.Value == "ETHUSD")])
usdAvailable = usdTotal - usdReserved
self.Debug("usdAvailable: {}".format(usdAvailable))

# Submit a marketable buy limit order for ETH at 1% above the current price
limitPrice = round(self.Securities["ETHUSD"].Price * d.Decimal(1.01), 2)

# use all of our available USD
quantity = usdAvailable / limitPrice

# this order will be rejected (for now) because of this issue:
self.LimitOrder("ETHUSD", quantity, limitPrice)

# use only half of our available USD
quantity = usdAvailable * d.Decimal(0.5) / limitPrice
self.LimitOrder("ETHUSD", quantity, limitPrice)

elif self.Time.hour == 11 and self.Time.minute == 0:
# Liquidate our BTC holdings (including the initial holding)
self.SetHoldings("BTCUSD", 0)

elif self.Time.hour == 12 and self.Time.minute == 0:
# Submit a market buy order for 1 BTC using EUR
self.Buy("BTCEUR", 1)

# Submit a sell limit order at 10% above market price
limitPrice = round(self.Securities["BTCEUR"].Price * d.Decimal(1.1), 2)
self.LimitOrder("BTCEUR", -1, limitPrice)

elif self.Time.hour == 13 and self.Time.minute == 0:
# Cancel the limit order if not filled

elif self.Time.hour > 13:
# To include any initial holdings, we read the LTC amount from the cashbook
# instead of using Portfolio["LTCUSD"].Quantity

if > self.slow:
if self.Portfolio.CashBook["LTC"].Amount == 0:
self.Buy("LTCUSD", 10)
if self.Portfolio.CashBook["LTC"].Amount > 0:
# The following two statements currently behave differently if we have initial holdings:

# self.SetHoldings("LTCUSD", 0)

def OnOrderEvent(self, orderEvent):
self.Debug("{} {}".format(self.Time, orderEvent.ToString()))

def OnEndOfAlgorithm(self):
self.Log("{} - TotalPortfolioValue: {}".format(self.Time, self.Portfolio.TotalPortfolioValue))
self.Log("{} - CashBook: {}".format(self.Time, self.Portfolio.CashBook))