Using Built-in Functions

Full list of functions provided in PFA specification is available here.

In [1]:

from titus.genpy import PFAEngine
inputs = range(1, 10)

One-parameter Functions¶

One-parameter functions accept a single input argument.
Examples:

m.sqrt
m.sin
m.cos
m.tan
m.exp
m.ln (natural logarithm)
m.log10 (logarithm base 10)
m.floor
m.ceil
m.round

One-parameter functions do not need to enclose arguments in square brackets: {"m.sin": 3.14} is permitted instead of {"m.sin": [3.14]}.

YAML

In [2]:

pfa = """
input: double
output: double
action: 
  - m.sqrt: [input]"""

In [3]:

engine, = PFAEngine.fromYaml(pfa)

In [4]:

for num in inputs:
    print(engine.action(num))

1.0
1.4142135623730951
1.7320508075688772
2.0
2.23606797749979
2.449489742783178
2.6457513110645907
2.8284271247461903
3.0

[ ] for single parameter function is not mandatory.

In [5]:

pfa = """
input: double
output: double
action: 
  - m.sqrt: input"""

In [6]:

engine, = PFAEngine.fromYaml(pfa)
for num in inputs:
    print(engine.action(num))

1.0
1.4142135623730951
1.7320508075688772
2.0
2.23606797749979
2.449489742783178
2.6457513110645907
2.8284271247461903
3.0

JSON

In [7]:

pfa = """
{
    "input":"double",
    "output":"double",
    "action":[
        {"m.sqrt": "input"}
    ]
}
"""

engine, = PFAEngine.fromJson(pfa)
for num in inputs:
    print(engine.action(num))

1.0
1.4142135623730951
1.7320508075688772
2.0
2.23606797749979
2.449489742783178
2.6457513110645907
2.8284271247461903
3.0

Two-parameter Functions¶

Two-parameter functions accept two input arguments.
Examples:

"+" (addition)
"-" (subtraction)
"x" (multiplication)
"/" (floating-point division)
"//" (integer division)
"u-" (negation)
"%" (modulo)
"%%" (remainder)
"xx" (exponentiation)

YAML

In [8]:

pfa = """
input: double
output: double
action:
  - {m.round: {"*": [{m.sin: {+: [input, 100]}}, 100]}}"""

engine2, = PFAEngine.fromYaml(pfa)
for num in inputs:
    print(engine2.action(num))

JSON

In [9]:

pfa = """
{
    "input": "double",
    "output": "double",
    "action": [{
        "m.round": {
            "*": [
                {"m.sin": {"+": ["input", 100]}}, 
                100
            ]
        }
    }]
}
"""

engine2, = PFAEngine.fromJson(pfa)
for num in inputs:
    print(engine2.action(num))