Technical Indicators¶

SQA::TAI provides access to 200+ technical analysis indicators from the TA-Lib C library. All indicators are accessible through simple, intuitive Ruby methods.

Indicator Categories¶

Overlap Studies¶

Moving averages and bands that overlay price charts:

Momentum Indicators¶

Measure the rate of price change:

Volatility Indicators¶

Measure market volatility and price range:

Volume Indicators¶

Analyze trading volume:

Pattern Recognition¶

Identify candlestick patterns:

Cycle Indicators¶

Hilbert Transform indicators for cycle analysis:

Price Transform Indicators¶

Transform OHLC data into representative prices:

Statistical Indicators¶

Statistical functions for trend analysis:

Usage Overview¶

All indicators follow a consistent API pattern:

require 'sqa/tai'

# Single input, single output
result = SQA::TAI.sma(prices, period: 10)

# Single input, multiple outputs
upper, middle, lower = SQA::TAI.bbands(prices, period: 20)

# Multiple inputs (OHLC data)
atr = SQA::TAI.atr(high, low, close, period: 14)

Common Parameters¶

Most indicators accept these standard parameters:

Parameter	Description	Default
`period`	Time period for calculation	Varies by indicator
`ma_type`	Moving average type (0=SMA, 1=EMA, etc.)	0 (SMA)
`nbdev_up`	Standard deviations for upper band	2.0
`nbdev_down`	Standard deviations for lower band	2.0

Return Values¶

Single output indicators return an array
Multiple output indicators return multiple arrays
Arrays may contain nil values for the warmup period
Use .compact to filter out nil values
Use .last to get the most recent value

Best Practices¶

Ensure sufficient data - Most indicators need a warmup period
Handle nil values - Check for nil before using values
Validate parameters - Use appropriate period lengths for your timeframe
Combine indicators - Use multiple indicators for confirmation
Backtest strategies - Always test before live trading

Example: Multi-Indicator Analysis¶

require 'sqa/tai'

# Load historical data
prices = load_stock_data('AAPL')

# Trend: Moving averages
sma_20 = SQA::TAI.sma(prices, period: 20)
sma_50 = SQA::TAI.sma(prices, period: 50)

# Momentum: RSI
rsi = SQA::TAI.rsi(prices, period: 14)

# Volatility: Bollinger Bands
upper, middle, lower = SQA::TAI.bbands(prices, period: 20)

# Analyze current conditions
current_price = prices.last
current_rsi = rsi.last

if current_price > sma_20.last && current_price > sma_50.last
  puts "Uptrend confirmed"
end

if current_rsi < 30
  puts "Oversold condition"
elsif current_rsi > 70
  puts "Overbought condition"
end

if current_price < lower.last
  puts "Price below lower Bollinger Band"
end