### Functions & Operators

**"{}" below represents placeholder, all expressions are not case sensitive, and “x” represents data time series**

`abs(x), log(x), sign(x)`

literally means absolute value, logarithm and sign function, respectively.

The following operators, including `+, -, *, /, >, <`

, also meet the meanings of their standards; `==`

represents “equal or not”; `||`

means “or”; `x? y: z`

indicates ternary operator.

`rank(x)`

: the ranking of cross-sections, returning the percentage of the location; it is necessary to specify multiple candidate target pools, which cannot be calculated for a single market and will directly return the original result.
`delay(x, d)`

: the value before the d period of the sequence.
`sma(x, d)`

: the simple moving average of the d period of the sequence.
`correlation(x, y, d)`

: the correlation coefficient of time series x and y over the past d periods.
`covariance(x, y, d)`

: the covariance of the time series x and y in the past d periods.
`scale(x, a)`

: it normalizes the data, so that `sum(abs(x)) = a`

(“a” defaults to 1).
`delta(x, d)`

: the current value of the time series x minus the value before d periods.
`signedpower(x, a)`

: `x^a`

.
`decay_linear(x, d)`

: weighted d-period moving average of time series x, with weights being d, d-1, d-2… 1 (normalized).
`indneutralize(x, g)`

: the neutral processing for industry classification “g”, currently not supported.
`ts_{O}(x, d)`

: perform “O” operations on the time series x in the past d periods (“O” can specifically represent “min” and “max”, etc., introduced later), “d” will be converted to an integer.
`ts_min(x, d)`

: the minimum value of the past d periods.
`ts_max(x, d)`

: the maximum value of the past d periods.
`ts_argmax(x, d)`

: `ts_max(x, d)`

position.
`ts_argmin(x, d)`

: `ts_min(x, d)`

position.
`ts_rank(x, d)`

: sorting of the past d periods time series x values (percentage sorting).
`min(x, d)`

: `ts_min(x, d)`

.
`max(x, d)`

: `ts_max(x, d)`

.
`sum(x, d)`

: the sum of the past d periods.
`product(x, d)`

: the product of the past d periods.
`stddev(x, d)`

: the standard deviation of the past d periods.

Data Exploration
Input Data