archive-gh-me/mathjs
1
0
Fork 0
mirror of https://github.com/josdejong/mathjs.git synced 2026-01-25 15:07:57 +00:00
Code Issues Projects Releases Wiki Activity

Support pow() as an argument for derivative() (#1417)

Browse Source 
* Support pow() as an argument for derivative()

Add support for the pow() function as an argument for math.derivative().

Fixes #1259.

* Unit tests for derivatives of pow()

* Support for derivate of pow() function
This commit is contained in:
sam-19 2019-03-02 11:37:43 +02:00 committed by Jos de Jong
parent 0905122757
commit 9bfdff1d06
2 changed files with 15 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/function/algebra/derivative.js
View File

@ -300,6 +300,10 @@ function factory (type, config, load, typed) {
]), constNodes)
}
break
case 'pow':
constNodes[arg1] = constNodes[node.args[1]]
// Pass to pow operator node parser
return _derivative(new OperatorNode('^', 'pow', [arg0, node.args[1]]), constNodes)
case 'exp':
// d/dx(e^x) = e^x
funcDerivative = new FunctionNode('exp', [arg0.clone()])
@ -746,7 +750,7 @@ function factory (type, config, load, typed) {
*/
function funcArgsCheck (node) {
// TODO add min, max etc
if ((node.name === 'log' || node.name === 'nthRoot') && node.args.length === 2) {
if ((node.name === 'log' || node.name === 'nthRoot' || node.name === 'pow') && node.args.length === 2) {
return
}

10
test/function/algebra/derivative.test.js
View File

@ -160,6 +160,16 @@ describe('derivative', function () {
compareString(derivativeWithoutSimplify('acoth((2x))', 'x'), '-(2 * 1) / (1 - (2 x) ^ 2)')
compareString(derivativeWithoutSimplify('abs(2x)', 'x'), '2 * 1 * abs(2 x) / (2 x)')
// See power operator tests above
compareString(derivativeWithoutSimplify('pow(0, 2^x + x^3 + 2)', 'x'), '0')
compareString(derivativeWithoutSimplify('pow(1, 2^x + x^3 + 2)', 'x'), '0')
compareString(derivativeWithoutSimplify('pow(10, 2x + 2)', 'x'), '10 ^ (2 x + 2) * log(10) * (2 * 1 + 0)')
compareString(derivativeWithoutSimplify('pow(x^x^x^x, 0)', 'x'), '0')
compareString(derivativeWithoutSimplify('pow(x + 2, 1)', 'x'), '1 + 0')
compareString(derivativeWithoutSimplify('2 * pow(x, 2)', 'x'), '2 * 2 * 1 * x ^ (2 - 1)')
compareString(derivativeWithoutSimplify('2 * pow(x, -2)', 'x'), '2 * -2 * 1 * x ^ (-2 - 1)')
compareString(derivativeWithoutSimplify('pow(x^3 + x, 5x + 2)', 'x'), '(x ^ 3 + x) ^ (5 x + 2) * ((3 * 1 * x ^ (3 - 1) + 1) * (5 x + 2) / (x ^ 3 + x) + (5 * 1 + 0) * log(x ^ 3 + x))')
compareString(derivativeWithoutSimplify('exp(2x)', 'x'), '2 * 1 * exp(2 x)')
})