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Some additional helper functions #7

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Some additional helper functions #7

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3dceb6e
fixed some changes
aliang8 Jun 28, 2017
b862d6f
added tests and fixed function
aliang8 Jun 30, 2017
c72cb3d
fixed getCofficientAndConstant
aliang8 Jun 30, 2017
f1d1e81
pushing
aliang8 Jun 30, 2017
9ccc904
fixed getCoefficientAndConstants
aliang8 Jun 30, 2017
4f769a2
fixed comments
aliang8 Jul 1, 2017
fc21cc9
fix 2^2 case
aliang8 Jul 1, 2017
7a26bad
nodeEquals in hasSameBase
aliang8 Jul 2, 2017
cbc3bb9
revert package
aliang8 Jul 2, 2017
b14fdeb
fixed some helper functions
aliang8 Jul 4, 2017
2ecf06c
fixes
aliang8 Jul 4, 2017
623f926
merge with master
aliang8 Jul 4, 2017
e94f341
made some changes
aliang8 Jul 4, 2017
0c40e27
more fixes
aliang8 Jul 4, 2017
b21ee85
fix getVariableFactors
aliang8 Jul 4, 2017
29938d4
fix getVariableFactors
aliang8 Jul 4, 2017
c669902
fixed
aliang8 Jul 5, 2017
2b31dfd
added some more changes to getCoefficientAndConstants
aliang8 Jul 5, 2017
62f8a0d
revert lines
aliang8 Jul 6, 2017
acde4be
added hasCoeff and negate
aliang8 Jul 6, 2017
8c5671b
fix lint
aliang8 Jul 6, 2017
caf9282
merge with master
aliang8 Jul 6, 2017
5df8e66
fixed comments
aliang8 Jul 6, 2017
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31 changes: 26 additions & 5 deletions lib/__test__/query.test.js
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
import assert from 'assert'
import {parse} from 'math-parser'
import {parse, print} from 'math-parser'
import stringify from 'json-stable-stringify'

const reverseAlphabetical = (a, b) => a.key < b.key ? 1 : -1
Expand Down Expand Up @@ -109,6 +109,27 @@ describe('query', () => {
assert(!query.isPolynomial(parse('1/x')))
})

it('hasCoeff', () => {
assert(query.hasCoeff(parse('2x')))
assert(query.hasCoeff(parse('2x^2')))
assert(query.hasCoeff(parse('2 x y z')))
assert(!query.hasCoeff(parse('2')))
assert(!query.hasCoeff(parse('x')))
})

it('negate', () => {
assert.equal(print(query.negate(parse('2'))), -2)
assert.equal(print(query.negate(parse('2x^2'))), `-2 x^2`)
assert.equal(print(query.negate(parse('2xyz'))), `-2 xyz`)
assert.equal(print(query.negate(parse('-2'))), 2)
assert.equal(print(query.negate(parse('-2x^2'))), `2 x^2`)
assert.equal(print(query.negate(parse('-2x^2 y^2'))), `2 x^2 y^2`)
assert.equal(print(query.negate(parse('2x^2 y^2'))), `-2 x^2 y^2`)
assert.equal(print(query.negate(parse('2/3'))), `-2 / 3`)
assert.equal(print(query.negate(parse('-2/3'))), `2 / 3`)
assert.equal(print(query.negate(parse('(x+3)/3'))), `-(x + 3) / 3`)
})

it('hasSameBase', () => {
assert(query.hasSameBase(parse('x^1'), parse('x^2')))
assert(query.hasSameBase(parse('(x+1)^2'), parse('(x+1)^x')))
Expand Down Expand Up @@ -225,10 +246,10 @@ describe('query', () => {
assert(!query.isRel(x))
})

it('isNumber', () => {
assert(query.isNumber(a))
assert(query.isNumber(parse('-2')))
assert(!query.isNumber(x))
it('isRationalNumber', () => {
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Maybe add some tests that check for factions and decimals.

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👍

assert(query.isRationalNumber(a))
assert(query.isRationalNumber(parse('-2')))
assert(!query.isRationalNumber(x))
})

it('getValue', () => {
Expand Down
56 changes: 40 additions & 16 deletions lib/query.js
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ export const isApply = node => node && node.type === 'Apply'
export const isParens = node => node && node.type === 'Parentheses'

// deprecated, use isApply
export const isOperation = node => isApply(node) && !isNumber(node)
export const isOperation = node => isApply(node) && !isRationalNumber(node)
export const isFunction = node => isApply(node) && isIdentifier(node.op)

// TODO: curry it?
Expand All @@ -26,9 +26,9 @@ export const isAbs = node => _isOp('abs', node)
export const isFact = node => _isOp('fact', node)
export const isNthRoot = node => _isOp('nthRoot', node)
export const isFraction = node => isNeg(node) ? isFraction(node.args[0]) : isDiv(node)
export const isConstantFraction = node => isFraction(node) && node.args.every(isNumber)
export const isConstantFraction = node => isFraction(node) && node.args.every(isRationalNumber)
export const isIntegerFraction = node => isFraction(node) && node.args.every(isInteger)
export const isDecimal = node => isNumber(node) && getValue(node) % 1 != 0
export const isDecimal = node => getValue(node) % 1 != 0

const relationIdentifierMap = {
'eq': '=',
Expand All @@ -41,25 +41,25 @@ const relationIdentifierMap = {

export const isRel = node => isApply(node) && node.op in relationIdentifierMap

export const isNumber = node => {
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I think we should keep isNumber in addition to isRationalNumber.

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@aliang8 aliang8 Jul 6, 2017 •
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Hmmm I don't see how it would be useful, but I add it back.

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I guess we isInteger. Okay, let's leave this as is. We can always add it back later if it does turn out we need it.

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Sure :D

if (node.type === 'Number') {
export const isRationalNumber = node => {
if (node.type === 'Number' || isConstantFraction(node) || isIntegerFraction(node) || isDecimal(node) ) {
return true
} else if (isNeg(node)) {
return isNumber(node.args[0])
return isRationalNumber(node.args[0])
} else {
return false
}
}

export const isInteger = node => {
return isNumber(node) && Number.isInteger(getValue(node))
return isRationalNumber(node) && Number.isInteger(getValue(node))
}

export const isPolynomial = (node) => {
if (isPolynomialTerm(node)) {
return true
} else if (isDiv(node)) {
return isNumber(getDenominator(node)) && isPolynomial(getNumerator(node))
return isRationalNumber(getDenominator(node)) && isPolynomial(getNumerator(node))
} else if (isAdd(node) || isMul(node)) {
return node.args.every(isPolynomialTerm)
} else {
Expand All @@ -70,10 +70,10 @@ export const isPolynomial = (node) => {
export const isVariableFactor = (node) =>
isIdentifier(node) ||
isPow(node) && (isPolynomial(node.args[0]) || isPolynomialTerm(node))
&& (isNumber(node.args[1]) || isVariableFactor(node.args[1]))
&& (isRationalNumber(node.args[1]) || isVariableFactor(node.args[1]))

export const isPolynomialTerm = (node) => {
if (isNumber(node) || isConstantFraction(node) || isDecimal(node)) {
if (isRationalNumber(node)) {
return true
} else if (isIdentifier(node)) {
return true
Expand Down Expand Up @@ -130,13 +130,13 @@ export const getDenominator = (node) => {
}

export const hasConstantBase = node => isPow(node) &&
(isNumber(node.args[0]) || isConstantFraction(node.args[0]) || isIntegerFraction(node.args[0]))
(isRationalNumber(node.args[0]) || isConstantFraction(node.args[0]) || isIntegerFraction(node.args[0]))

// TODO: handle multivariable polynomials
// Get degree of a polynomial term
// e.g. 6x^2 -> 2
export const getPolyDegree = (node) => {
if (isNumber(node)) {
if (isRationalNumber(node)) {
return build.number(0)
} else if (isIdentifier(node)) {
return build.number(1)
Expand All @@ -156,14 +156,14 @@ export const getPolyDegree = (node) => {

// TODO: 2^2
export const getCoefficient = (node) => {
if (isNumber(node) || hasConstantBase(node)) {
if (isRationalNumber(node) || hasConstantBase(node)) {
return node
} else if (isIdentifier(node) || isPow(node)) {
return build.numberNode('1')
} else if (isNeg(node)) {
return build.neg(getCoefficient(node.args[0]), {wasMinus: node.wasMinus})
} else if (isMul(node)) {
const numbers = node.args.filter(arg => isNumber(arg) || isConstantFraction(arg))
const numbers = node.args.filter(arg => isRationalNumber(arg) || isConstantFraction(arg))
if (numbers.length > 1) {
return build.mul(...numbers)
} else if (numbers.length === 1) {
Expand Down Expand Up @@ -210,7 +210,7 @@ export const sortVariables = (variables) =>
{constants: [3], coefficientMap: ['x^2': [2, 5], 'x': [3]]}
*/
export const getCoefficientsAndConstants = (node, coefficientMap = {}, constants = [], others = []) => {
if (isNumber(node) || isConstantFraction(node)) {
if (isRationalNumber(node) || isConstantFraction(node)) {
constants.push(node)
} else if (isFunction(node) || hasConstantBase(node)) {
// cos, sin, f(a), etc
Expand All @@ -233,7 +233,7 @@ export const getCoefficientsAndConstants = (node, coefficientMap = {}, constants
coefficientMap[key].push(coefficient)
}
} else if(isPolynomial(node) || isAdd(node) || (isMul(node) && node.args.every(isPolynomialTerm))) {
// 2x^2 + 3x + 1, 3x^2 * 2x^2
// 2x^2 + 3x + 1, 3x^2 * 2x^2, x + 4 + x + 2^x
node.args.forEach(function(arg) {
getCoefficientsAndConstants(arg, coefficientMap, constants, others)
})
Expand All @@ -255,3 +255,27 @@ export const hasSameBase = (node1, node2) => {
}

export const nodeEquals = (node1, node2) => print(node1) === print(node2)

export const hasCoeff = (node) => {
return isPolynomialTerm(node) && !isIdentifier(node) && !isRationalNumber(node)
}

// e.g 3 -> -3, -3x -> 3x, x + 3 -> -(x + 3), 2/3 -> -2 / 3
export const negate = (node) => {
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I think this should be part of build not query.

if (isNeg(node)) {
return node.args[0]
} else if (isAdd(node)) {
return build.neg(node)
} else if (isFraction(node)) {
return build.div(negate(getNumerator(node)), getDenominator(node))
} else if (isPolynomialTerm(node)) {
if (isNeg(getCoefficient(node))) {
return build.apply(
'mul',
[negate(getCoefficient(node)), ...node.args.slice(1)],
{implicit: node.implicit})
} else {
return build.neg(node)
}
}
}