generators/python/math.js
/**
* @license
* Visual Blocks Language
*
* Copyright 2012 Google Inc.
* https://blockly.googlecode.com/
*
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Generating Python for math blocks.
* @author q.neutron@gmail.com (Quynh Neutron)
*/
'use strict';
goog.provide('Blockly.Python.math');
goog.require('Blockly.Python');
// If any new block imports any library, add that library name here.
Blockly.Python.addReservedWords('math,random');
Blockly.Python['math_number'] = function(block) {
// Numeric value.
var code = parseFloat(block.getFieldValue('NUM'));
var order = code < 0 ? Blockly.Python.ORDER_UNARY_SIGN :
Blockly.Python.ORDER_ATOMIC;
return [code, order];
};
Blockly.Python['math_arithmetic'] = function(block) {
// Basic arithmetic operators, and power.
var OPERATORS = {
'ADD': [' + ', Blockly.Python.ORDER_ADDITIVE],
'MINUS': [' - ', Blockly.Python.ORDER_ADDITIVE],
'MULTIPLY': [' * ', Blockly.Python.ORDER_MULTIPLICATIVE],
'DIVIDE': [' / ', Blockly.Python.ORDER_MULTIPLICATIVE],
'POWER': [' ** ', Blockly.Python.ORDER_EXPONENTIATION]
};
var tuple = OPERATORS[block.getFieldValue('OP')];
var operator = tuple[0];
var order = tuple[1];
var argument0 = Blockly.Python.valueToCode(block, 'A', order) || '0';
var argument1 = Blockly.Python.valueToCode(block, 'B', order) || '0';
var code = argument0 + operator + argument1;
return [code, order];
// In case of 'DIVIDE', division between integers returns different results
// in Python 2 and 3. However, is not an issue since Blockly does not
// guarantee identical results in all languages. To do otherwise would
// require every operator to be wrapped in a function call. This would kill
// legibility of the generated code. See:
// http://code.google.com/p/blockly/wiki/Language
};
Blockly.Python['math_single'] = function(block) {
// Math operators with single operand.
var operator = block.getFieldValue('OP');
var code;
var arg;
if (operator == 'NEG') {
// Negation is a special case given its different operator precedence.
var code = Blockly.Python.valueToCode(block, 'NUM',
Blockly.Python.ORDER_UNARY_SIGN) || '0';
return ['-' + code, Blockly.Python.ORDER_UNARY_SIGN];
}
Blockly.Python.definitions_['import_math'] = 'import math';
if (operator == 'SIN' || operator == 'COS' || operator == 'TAN') {
arg = Blockly.Python.valueToCode(block, 'NUM',
Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
} else {
arg = Blockly.Python.valueToCode(block, 'NUM',
Blockly.Python.ORDER_NONE) || '0';
}
// First, handle cases which generate values that don't need parentheses
// wrapping the code.
switch (operator) {
case 'ABS':
code = 'math.fabs(' + arg + ')';
break;
case 'ROOT':
code = 'math.sqrt(' + arg + ')';
break;
case 'LN':
code = 'math.log(' + arg + ')';
break;
case 'LOG10':
code = 'math.log10(' + arg + ')';
break;
case 'EXP':
code = 'math.exp(' + arg + ')';
break;
case 'POW10':
code = 'math.pow(10,' + arg + ')';
break;
case 'ROUND':
code = 'round(' + arg + ')';
break;
case 'ROUNDUP':
code = 'math.ceil(' + arg + ')';
break;
case 'ROUNDDOWN':
code = 'math.floor(' + arg + ')';
break;
case 'SIN':
code = 'math.sin(' + arg + ' / 180.0 * math.pi)';
break;
case 'COS':
code = 'math.cos(' + arg + ' / 180.0 * math.pi)';
break;
case 'TAN':
code = 'math.tan(' + arg + ' / 180.0 * math.pi)';
break;
}
if (code) {
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
}
// Second, handle cases which generate values that may need parentheses
// wrapping the code.
switch (operator) {
case 'ASIN':
code = 'math.asin(' + arg + ') / math.pi * 180';
break;
case 'ACOS':
code = 'math.acos(' + arg + ') / math.pi * 180';
break;
case 'ATAN':
code = 'math.atan(' + arg + ') / math.pi * 180';
break;
default:
throw 'Unknown math operator: ' + operator;
}
return [code, Blockly.Python.ORDER_MULTIPLICATIVE];
};
Blockly.Python['math_constant'] = function(block) {
// Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
var CONSTANTS = {
'PI': ['math.pi', Blockly.Python.ORDER_MEMBER],
'E': ['math.e', Blockly.Python.ORDER_MEMBER],
'GOLDEN_RATIO': ['(1 + math.sqrt(5)) / 2', Blockly.Python.ORDER_MULTIPLICATIVE],
'SQRT2': ['math.sqrt(2)', Blockly.Python.ORDER_MEMBER],
'SQRT1_2': ['math.sqrt(1.0 / 2)', Blockly.Python.ORDER_MEMBER],
'INFINITY': ['float(\'inf\')', Blockly.Python.ORDER_ATOMIC]
};
var constant = block.getFieldValue('CONSTANT');
if (constant != 'INFINITY') {
Blockly.Python.definitions_['import_math'] = 'import math';
}
return CONSTANTS[constant];
};
Blockly.Python['math_number_property'] = function(block) {
// Check if a number is even, odd, prime, whole, positive, or negative
// or if it is divisible by certain number. Returns true or false.
var number_to_check = Blockly.Python.valueToCode(block, 'NUMBER_TO_CHECK',
Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
var dropdown_property = block.getFieldValue('PROPERTY');
var code;
if (dropdown_property == 'PRIME') {
Blockly.Python.definitions_['import_math'] = 'import math';
var functionName = Blockly.Python.provideFunction_(
'math_isPrime',
['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(n):',
' # https://en.wikipedia.org/wiki/Primality_test#Naive_methods',
' # If n is not a number but a string, try parsing it.',
' if type(n) not in (int, float, long):',
' try:',
' n = float(n)',
' except:',
' return False',
' if n == 2 or n == 3:',
' return True',
' # False if n is negative, is 1, or not whole,' +
' or if n is divisible by 2 or 3.',
' if n <= 1 or n % 1 != 0 or n % 2 == 0 or n % 3 == 0:',
' return False',
' # Check all the numbers of form 6k +/- 1, up to sqrt(n).',
' for x in range(6, int(math.sqrt(n)) + 2, 6):',
' if n % (x - 1) == 0 or n % (x + 1) == 0:',
' return False',
' return True']);
code = functionName + '(' + number_to_check + ')';
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
}
switch (dropdown_property) {
case 'EVEN':
code = number_to_check + ' % 2 == 0';
break;
case 'ODD':
code = number_to_check + ' % 2 == 1';
break;
case 'WHOLE':
code = number_to_check + ' % 1 == 0';
break;
case 'POSITIVE':
code = number_to_check + ' > 0';
break;
case 'NEGATIVE':
code = number_to_check + ' < 0';
break;
case 'DIVISIBLE_BY':
var divisor = Blockly.Python.valueToCode(block, 'DIVISOR',
Blockly.Python.ORDER_MULTIPLICATIVE);
// If 'divisor' is some code that evals to 0, Python will raise an error.
if (!divisor || divisor == '0') {
return ['False', Blockly.Python.ORDER_ATOMIC];
}
code = number_to_check + ' % ' + divisor + ' == 0';
break;
}
return [code, Blockly.Python.ORDER_RELATIONAL];
};
Blockly.Python['math_change'] = function(block) {
// Add to a variable in place.
var argument0 = Blockly.Python.valueToCode(block, 'DELTA',
Blockly.Python.ORDER_ADDITIVE) || '0';
var varName = Blockly.Python.variableDB_.getName(block.getFieldValue('VAR'),
Blockly.Variables.NAME_TYPE);
return varName + ' = (' + varName + ' if type(' + varName +
') in (int, float, long) else 0) + ' + argument0 + '\n';
};
// Rounding functions have a single operand.
Blockly.Python['math_round'] = Blockly.Python['math_single'];
// Trigonometry functions have a single operand.
Blockly.Python['math_trig'] = Blockly.Python['math_single'];
Blockly.Python['math_on_list'] = function(block) {
// Math functions for lists.
var func = block.getFieldValue('OP');
var list = Blockly.Python.valueToCode(block, 'LIST',
Blockly.Python.ORDER_NONE) || '[]';
var code;
switch (func) {
case 'SUM':
code = 'sum(' + list + ')';
break;
case 'MIN':
code = 'min(' + list + ')';
break;
case 'MAX':
code = 'max(' + list + ')';
break;
case 'AVERAGE':
var functionName = Blockly.Python.provideFunction_(
'math_mean',
// This operation excludes null and values that are not int or float:',
// math_mean([null, null, "aString", 1, 9]) == 5.0.',
['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(myList):',
' localList = [e for e in myList if type(e) in (int, float, long)]',
' if not localList: return',
' return float(sum(localList)) / len(localList)']);
code = functionName + '(' + list + ')';
break;
case 'MEDIAN':
var functionName = Blockly.Python.provideFunction_(
'math_median',
// This operation excludes null values:
// math_median([null, null, 1, 3]) == 2.0.
['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(myList):',
' localList = sorted([e for e in myList ' +
'if type(e) in (int, float, long)])',
' if not localList: return',
' if len(localList) % 2 == 0:',
' return (localList[len(localList) / 2 - 1] + ' +
'localList[len(localList) / 2]) / 2.0',
' else:',
' return localList[(len(localList) - 1) / 2]']);
code = functionName + '(' + list + ')';
break;
case 'MODE':
var functionName = Blockly.Python.provideFunction_(
'math_modes',
// As a list of numbers can contain more than one mode,
// the returned result is provided as an array.
// Mode of [3, 'x', 'x', 1, 1, 2, '3'] -> ['x', 1].
['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(some_list):',
' modes = []',
' # Using a lists of [item, count] to keep count rather than dict',
' # to avoid "unhashable" errors when the counted item is ' +
'itself a list or dict.',
' counts = []',
' maxCount = 1',
' for item in some_list:',
' found = False',
' for count in counts:',
' if count[0] == item:',
' count[1] += 1',
' maxCount = max(maxCount, count[1])',
' found = True',
' if not found:',
' counts.append([item, 1])',
' for counted_item, item_count in counts:',
' if item_count == maxCount:',
' modes.append(counted_item)',
' return modes']);
code = functionName + '(' + list + ')';
break;
case 'STD_DEV':
Blockly.Python.definitions_['import_math'] = 'import math';
var functionName = Blockly.Python.provideFunction_(
'math_standard_deviation',
['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(numbers):',
' n = len(numbers)',
' if n == 0: return',
' mean = float(sum(numbers)) / n',
' variance = sum((x - mean) ** 2 for x in numbers) / n',
' return math.sqrt(variance)']);
code = functionName + '(' + list + ')';
break;
case 'RANDOM':
Blockly.Python.definitions_['import_random'] = 'import random';
code = 'random.choice(' + list + ')';
break;
default:
throw 'Unknown operator: ' + func;
}
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
};
Blockly.Python['math_modulo'] = function(block) {
// Remainder computation.
var argument0 = Blockly.Python.valueToCode(block, 'DIVIDEND',
Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
var argument1 = Blockly.Python.valueToCode(block, 'DIVISOR',
Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
var code = argument0 + ' % ' + argument1;
return [code, Blockly.Python.ORDER_MULTIPLICATIVE];
};
Blockly.Python['math_constrain'] = function(block) {
// Constrain a number between two limits.
var argument0 = Blockly.Python.valueToCode(block, 'VALUE',
Blockly.Python.ORDER_NONE) || '0';
var argument1 = Blockly.Python.valueToCode(block, 'LOW',
Blockly.Python.ORDER_NONE) || '0';
var argument2 = Blockly.Python.valueToCode(block, 'HIGH',
Blockly.Python.ORDER_NONE) || 'float(\'inf\')';
var code = 'min(max(' + argument0 + ', ' + argument1 + '), ' +
argument2 + ')';
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
};
Blockly.Python['math_random_int'] = function(block) {
// Random integer between [X] and [Y].
Blockly.Python.definitions_['import_random'] = 'import random';
var argument0 = Blockly.Python.valueToCode(block, 'FROM',
Blockly.Python.ORDER_NONE) || '0';
var argument1 = Blockly.Python.valueToCode(block, 'TO',
Blockly.Python.ORDER_NONE) || '0';
var code = 'random.randint(' + argument0 + ', ' + argument1 + ')';
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
};
Blockly.Python['math_random_float'] = function(block) {
// Random fraction between 0 and 1.
Blockly.Python.definitions_['import_random'] = 'import random';
return ['random.random()', Blockly.Python.ORDER_FUNCTION_CALL];
};