Files
blockly/generators/python/math.js
Neil Fraser 90b3f75d82 Remove @author tags (#5601)
Our files are up to a decade old, and have churned so much, that the initial author of the file no longer has much meaning.

Furthermore, this will encourage developers to post to the developer group, rather than emailing Googlers (usually me) directly.
2021-10-15 09:50:46 -07:00

385 lines
14 KiB
JavaScript

/**
* @license
* Copyright 2012 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Generating Python for math blocks.
*/
'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,Number');
Blockly.Python['math_number'] = function(block) {
// Numeric value.
var code = Number(block.getFieldValue('NUM'));
var order;
if (code === Infinity) {
code = 'float("inf")';
order = Blockly.Python.ORDER_FUNCTION_CALL;
} else if (code === -Infinity) {
code = '-float("inf")';
order = Blockly.Python.ORDER_UNARY_SIGN;
} else {
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.
};
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.
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 Error('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';
Blockly.Python.definitions_['from_numbers_import_Number'] =
'from numbers import Number';
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 not isinstance(n, Number):',
' 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.
Blockly.Python.definitions_['from_numbers_import_Number'] =
'from numbers import Number';
var argument0 = Blockly.Python.valueToCode(block, 'DELTA',
Blockly.Python.ORDER_ADDITIVE) || '0';
var varName = Blockly.Python.nameDB_.getName(block.getFieldValue('VAR'),
Blockly.VARIABLE_CATEGORY_NAME);
return varName + ' = (' + varName + ' if isinstance(' + varName +
', Number) 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':
Blockly.Python.definitions_['from_numbers_import_Number'] =
'from numbers import Number';
var functionName = Blockly.Python.provideFunction_(
'math_mean',
// This operation excludes null and values that aren't 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 isinstance(e, Number)]',
' if not localList: return',
' return float(sum(localList)) / len(localList)']);
code = functionName + '(' + list + ')';
break;
case 'MEDIAN':
Blockly.Python.definitions_['from_numbers_import_Number'] =
'from numbers import Number';
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 isinstance(e, Number)])',
' 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 Error('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];
};
Blockly.Python['math_atan2'] = function(block) {
// Arctangent of point (X, Y) in degrees from -180 to 180.
Blockly.Python.definitions_['import_math'] = 'import math';
var argument0 = Blockly.Python.valueToCode(block, 'X',
Blockly.Python.ORDER_NONE) || '0';
var argument1 = Blockly.Python.valueToCode(block, 'Y',
Blockly.Python.ORDER_NONE) || '0';
return ['math.atan2(' + argument1 + ', ' + argument0 + ') / math.pi * 180',
Blockly.Python.ORDER_MULTIPLICATIVE];
};