Function Calls

Function calls

A sub selection of the ML functionality is now supported as a set of variadic functions and can be called in a similar manner to python functions when imported to q using embedPy (more information here). These functions have been defined with a maximum of 8 input parameters, where any number of these can be optional, depending on the nature of the function itself. In addition to the varying number of arguments, users can also pass in a mixture of positional and keyword arguments.

Similarly to embedPy, the key things to note are:

• Default arguments will be applied where no explicit arguments are given
• Positional arguments can be used based on the initial function definition
• Individual keyword arguments are specified using the (infix) .var.kw operator (like embedPy pykw)
• A dictionary of keyword arguments can be passed using .var.kwargs (like embedPy pykwargs or python **kwargs)
• Keyword arguments last - We can combine positional arguments, lists of positional arguments, keyword arguments and a dictionary of keyword arguments. However, all keyword arguments must always follow any positional arguments. The dictionary of keyword arguments (if given) must be specified last.

Example function calls

Examples demonstrating different variadic combinations of arguments are shown below.

• Variadic function with single required argument
$cat example1.q \l init.q // Define an appropriate specification ensuring that X is defined as // a required input to the function spec:(!) . flip ( (description;"test specification"); (config ; namerequireddefault!/:( (X ;1b; ::); (y ;0b; 10); (func ;0b;max); (multi;0b; 4) ) ) ) // Define the function to be made variadic function:{[X;y;func;multi] multi*func y*X } // Compose the variadic function qfunc:.var.compose .var.generate[spec;function] // Load example script with variadic function qfunc which requires data$ q example1.q

// Using required arguments only
q)qfunc 100?1f

// Using required and positional arguments
q)qfunc[100?1f;5;med]

// Using required and named arguments
q)qfunc[100?1f;9;.var.kw[multi;9]]

// Using required and dictionary arguments
q)qfunc[100?1f;.var.kwargsfuncmulti!(med;15)]

• Variadic function with multiple required arguments
$cat example2.q \l init.q // Define an appropriate specification ensuring that X is defined as // a required input to the function spec:(!) . flip ( (description;"test specification"); (config ; namerequireddefault!/:( (X ;1b; ::); (y ;1b; ::); (func ;0b;max); (multi;0b; 4) ) ) ) // Define the function to be made variadic function:{[X;y;func;multi] multi*func y*X } // Compose the variadic function qfunc:.var.compose .var.generate[spec;function] // Load example script with variadic function qfunc which requires // 2 arguments, which are both lists of data$ q example2.q

// Using required arguments only
q)qfunc[100?1f;5]

// Using required and positional arguments
q)qfunc[100?1f;9;med]

// Using required and named arguments
q)qfunc[100?1f;15;.var.kw[multi;9]]

// Using required and dictionary arguments
q)qfunc[100?1f;2;.var.kwargsfuncmulti!(med;15)]